ECOLOGICAL DISTRIBUTION SAN JUAN BASIN, New Mexico

ECOLOGICAL DISTRIBUTION

of some vertebrates in the SAN JUAN BASIN, New Mexico

by Arthur H. Harris with sections by William J. Koster and David M. Niles number

8 Museum of New Mexico Papers in Anthropology Santa Fe, 1963

Museum of New Mexico Press

A Salvage Archaeology program conducted by the Museum of New Mexico in co-operation with the National Park Service, Southwest Region, Department of the Interior, in the Navajo Reservoir District of the Upper Colorado Storage Project.

Edited by RICHARD WORMSER Editor of Publications, Division of Anthropology

© Museum of New Mexico Press 1963

NAVAJO PROJECT STUDIES VII

Library of Congress Catalog Card Number: 63 -63281 Price $2.50

TABLE OF CONTENTS FOREWORD ................................................................................................................................................................................ 7 INTRODUCTION…………………………………………………………………………………………………………………………………. 8 Topography ................................................................................................................................... 9 Vegetation ......................................................................................................................................................................... 10 Pinyon-Juniper ..................................................................................................................................................... 10 Relict Conifer ........................................................................................................................................................ 12 Sagebrush .............................................................................................................................................................. 12 Riparian ................................................................................................................................................................. 12 Ponderosa Pine -Douglas Fir ............................................................................................................................... 15 Grassland ............................................................................................................................................................... 15 Cultivated Areas ................................................................................................................................................... 15 Climate .............................................................................................................................................................................. 15 Presentation of Data ....................................................................................................................................................... 16 ACCOUNTS OF SPECIES ........................................................................................................................................................ 17 Amphibians ....................................................................................................................................................................... 17 Ambystoma tigrinum Green ................................................................................................................................ 17 Scaphiopus bombifrons Cope .............................................................................................................................. 17 Bufo boreas Baird and Girard ........................................................................................................................... 17 Bufo woodhousei Girard ...................................................................................................................................... 17 Pseudacris nigrita Le Conte ................................................................................................................................. 18 Rana catesbeiana Shaw .................................................................................................................................... 18 Rana pipiens Schreber ......................................................................................................................................... 18 Reptiles ............................................................................................................................................................................. 19 Chrysemys picta Schneider.................................................................................................................................. 19 Crotaphytus collaris Say ..................................................................................................................................... 19 Holbrookia maculata Girard ................................................................................................................................ 19 Sceloporus undulatus Latreille ......................................................................................................................... 20 Sceloporus graciosus Baird and Girard .......................................................................................................... 20 Sceloporus Wiegmann .......................................................................................................................................... 21 Uta stansburiana Baird and Girard .................................................................................................................. 21 Urosaurus ornatus Hallowell .............................................................................................................................. 22 Phrynosoma cornutum (Harlan) .......................................................................................................................... 22 Phrynosoma douglassi (Bell) ............................................................................................................................... 22 Cnemidophorus tigris Baird and Girard ........................................................................................................... 22 Cnemidophorus velox Springer .......................................................................................................................... 23 Cnemidophorus inornatus Baird. ...................................................................................................................... 23 Cnemidophorus Wagler ....................................................................................................................................... 24 Eumeces multivirgatus Taylor .......................................................................................................................... 24 Thamnophis cyrtopsis (Kennicott) ..................................................................................................................... 24 Thamnophis elegans (Baird and Girard) ......................................................................................................... 25 Opheodrys vernalis (Harlan) ................................................................................................................................ 25 Arizona elegans Kennicott .................................................................................................................................. 25 Pituophis catenifer (Blainville) ............................................................................................................................ 26 Masticophis taeniatus (Hallowell) ...................................................................................................................... 26 Lampropeltis doliata (Linnaeus) ........................................................................................................................ 26 Crotalus viridis (Rafinesque) .............................................................................................................................. 26 Mammals ........................................................................................................................................................................... 27 Sorex vagrans Baird ........................................................................................................................................... 27 Myotis yumanensis (H. Allen) ............................................................................................................................. 27 Myotis evotis (H. Allen) ....................................................................................................................................... 27 Myotis volans (H. Allen) ...................................................................................................................................... 27 Myotis californicus (Audubon and Backman) .................................................................................................. 28 Myotis subulatus (Say) ........................................................................................................................................ 28 Lasionycteris noctivagans (Le Conte) ................................................................................................................ 28 Pipistrellus hesperus (H. Allen) ......................................................................................................................... 28 Eptesicus fuscus (Palisot de Beauvois) ............................................................................................................ 29 Lasiurus cinereus (Palisot de Beauvois) .......................................................................................................... 29 Euderma maculatum ( J. A. Allen) .................................................................................................................... 29 Plecotus townsendi Cooper ................................................................................................................................ 29 Antrozous pallidus (Le Conte) ............................................................................................................................ 30

Tadarida molossa ( P a l l a s ) ………..…………………………………………………………….………………………….30 Sylvilagus nuttalli (Bachman) .......................................................................................................................... 31 Sylvilagus auduboni (Baird) .............................................................................................................................. 31 Sylvilagus Gray .................................................................................................................... 32 Lepus californicus Gray ..................................................................................................................................... 32 Eutamias minimus (Bachman) .......................................................................................................................... 32 Eutamias quadrivittatus (Say) .......................................................................................................................... 32 Marmota flaviventris (Audubon and Bachman) ............................................................................................. 33 Citellus leucurus (Merriam) ............................................................................................................................... 34 Citellus spilosma (Bennett) ............................................................................................................................... 34 Citellus variegatus (Erxleben) ......................................................................................................................... 34 Citellus lateralis (Say) ........................................................................................................................................ 34 Cynomys gunnisoni (Baird) ............................................................................................................................... 35 Sciurus aberti Woodhouse ................................................................................................................................. 35 Thomomys bottae (Eydoux and Gervais) ......................................................................................................... 35 Thomomys talpoides (Richardson)..................................................................................................................... 35 Perognathus flavus Baird.................................................................................................................................... 36 Perognathus apache Merriam ........................................................................................................................... 36 Perognathus Wied-Neuwied ............................................................................................................................... 36 Dipodomys ordi Woodhouse .............................................................................................................................. 37 Dipodomys spectabilis Merriam ....................................................................................................................... 37 Castor canadensis Kuhl ..................................................................................................................................... 37 Reithrodontomys megalotis (Baird) .................................................................................................................. 37 Peromyscus crinitus (Merriam) ......................................................................................................................... 38 Peromyscus maniculatus (Wagner) ................................................................................................................. 38 Peromyscus boylii (Baird) .................................................................................................................................. 39 Peromyscus truei (Schufeldt) ........................................................................................................................... 39 Peromyscus Gloger ............................................................................................................................................. 40 Onychomys leucogaster (Wied-Neuwied) .......................................................................................................... 40 Neotoma albigula Hartley .................................................................................................................................. 41 Neotoma stephensi Goldman ............................................................................................................................. 41 Neotoma mexicana Baird ................................................................................................................................... 42 Neotoma cinerea (Ord) ...................................................................................................................................... 42 Neotoma Say and Ord ........................................................................................................................................ 42 Microtus pennsylvanicus (Ord) ......................................................................................................................... 42 Microtus montanus (Peale) ................................................................................................................................ 43 Microtus longicaudus (Merriam) ...................................................................................................................... 43 Microtus Schrank ............................................................................................................................................... 43 Ondatra zibethicus (Linnaeus) ......................................................................................................................... 44 Mus musculus Linnaeus ................................................................................................................................... 44 Zapus princeps J . A . A l l e n ................................................................................................................................. 44 Erethizon dorsatum (Linnaeus) ......................................................................................................................... 44 Canis latrans Say ................................................................................................................................................ 45 Canis lupus Linnaeus ....................................................................................................................................... 45 Vulpes fulva (Desmaret) ..................................................................................................................................... 45 Vulpes macrotis Merriam ................................................................................................................................. 45 Urocyon cinereoargenteus (Schreber).............................................................................................................. 46 Ursus americanus Pallas .................................................................................................................................... 46 Ursus horribilis Ord .......................................................................................................................................... 46 Bassariscus astutus (Lichtenstein) ................................................................................................................. 46 Procyon lotor (Linnaeus) ..................................................................................................................................... 46 Mustela frenata Lichtenstein ........................................................................................................................... 46 Mustela vison Schreber ...................................................................................................................................... 47 Taxidea taxus (Schreber) .................................................................................................................................... 47 Spilogale putorius (Linnaeus) ........................................................................................................................... 47 Mephitis mephitis (Schreber) ........................................................................................................................... 47 Felis concolor Kerr .............................................................................................................................................. 47 Lynx rufus (Schreber) ....................................................................................................................................... 48 Cervus canadensis Erxleben ............................................................................................................................. 48 Odocoileus hemionus (Rafinesque) .................................................................................................................. 48 Antilocapra americana (Ord). ............................................................................................................................ 48 Ammotragus lervia Pallas ................................................................................................................................. 48 DISCUSSION .......................................................................................................................................................................... 49 APPENDIX A – THE FISHES OF THE NAVAJO RESERVOIR DISTRICT BY WILLIAM J. KOSTER . . ...................... 54 APPENDIX B – BIRDS NOTED IN THE NAVAJO RESERVOIR DISTRICT BY DAVID M. NILES . . . ........................ 56 BIBLIOGRAPHY ...................................................................................................................................................................... 62 List of Previous Navajo Project Studies ............................................................................................................................ 64

LIST OF FIGURES 1. Pinyon -juniper growth on canyon sides overlooking the Pine River just above its junction with the San Juan ........................................................................................................................................................9 2 . Relict co nifer stand in Benito Canyon near its junction with the Pine River ......................................................... 11 3.

Sagebrush country south of the San Juan River ......................................................................................................13

4.

Two views of riparian habitat along the Pine River ..................................................................................................13

5. 6.

Poorly developed ponderosa pine-Douglas fir habitat on flanks of Chimney Rock Me sa, west side of the Piedra River Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Cultivated land within the Arboles Land Form .........................................................................................................14

7.

Roost of Tadarida molossa ................................ .................................................................................. 30

8.

Perognathus apache habitat in pinyon -juniper growth ............................................................................................ 36

9.

Approximate distributions of member species of Groups II, III, and IV ..................................................................50

10. Approximate distributions of member species of Groups V, VI, VII, and VIII .......................................................51 11. Approximate distributions of member species of Group IX ..................................................................................... 52 12. List of species composing nine groups of associated animals ................................................................................. 53

TABLE I. Temperature and Precipitation Records from Seven Stations .................................................................................. 16

FOREWORD

In itia l survey s and exca va tion s in the Na va jo Reservoir District brough t to light pa st even ts appa ren tly ca used by environ m en ta l chan ges ( D i t t e r t , et a l, 1961 , p . 1 6 ) . Ava ilab le evid en ce suggested th a t the chang es, th ough m in or, had resulted in d em og raph ic sh ifts and certa in cultural chang es. In vestiga tion s of severa l ty pes were devised to determine whether or not the suggested chang es ha d a ba sis in fa ct and, if so, their magnitude and temporal placement. Jam es S . Find ley of the Depa rtment of Biology , Un iversity of New Mexico, p roposed that a systematic field study and collection of living vertebra te fa una b e mad e to d etermine th e m ean ing , in environm en ta l term s, of the occurren ce of a g iven sp ecies a t an archaeolog ica l site. In add ition, the collection provid es compa ra tive ma teria l so tha t a rchaeolog ica l b on e sp ecimen ma y b e id en tified at the lowest p ossib le taxon om ic l e v e l . In the following paper, Arthur H. Harris, of th e Depa rtm en t of Biology , Un iversity of New Mexico, presen ts th e results of the field

faunal study. The data describe present fau nal assemblages, distributions, new records, and similar information without the interpretation of past events as represented in archaeological specimens. Thus, it is primarily a biological report, but indispensable for future interpretation of archaeological bone specimens. Studies of the latter material are now in progress. In addition, the study area covered by the investigations is sufficiently large to serve the same purposes for archaeological work being carried out in the Irrigation District of the Navajo P r o j e c t . Also, a study of the fishes represented in the San Juan and Pine Rivers has been made by William J. Koster, and one of birds by David M. Niles. Like other vertebrate remains, the study of present fishes and birds becomes important for archaeological purposes because of their use by the previous inhabitants of the Navajo Reservoir D is tr ic t. Alfred E. Dittert, Jr.

INTRODUCTION

Navajo Dam, part of the Colorado River Project complex, nearing completion on the San Juan River, some fifteen miles south of the New Mexico-Colorado state line, will hold back a reservoir extending five to six miles into Colorado along the San Juan and Piedra Rivers and almost to the state line along the Pine River, a major tributary of the San Juan. Irrigation lands to be fed from the Reservoir will extend sporadically west along and to the south of the San Juan, almost to the Arizona state line.

The School of American Research, until the summer of 1959, and the Museum of New Mexico, since then, have carried out salvage archaeology operations in the Dam and Reservoir areas under contract with Southwest Region of the National Park Service. Similar operations will be carried out in the lands to be irrigate d. To provide data on present vertebrate distribution and ecology for later interpretation of archaeological data, the author spent two weeks of August, 1958, and the summers of 1959 and 1960 in the field for the above institutions.

Primary emphasis has been upon the mammals, with se condary atte nt ion to re pt i le s a nd am p h i b i a ns . We l l o ve r 1 2 0 0 s pe cimens, collected by trapping and shooting, were preserved for study in the laboratory. Other specimens were collected, identified, and discarded in the field. Plant specimens, noted on environmental features, and comments of local inhabitants also were collected.

The area investigated during the periods of study includes most of those areas in which salvage archaeology will be carried out in the immediate future. The area has not been covered with equal attention to all parts, most work having been done in the

v i c i n i t y o f th e D a m and Re se r vo i r. I n a d di tion to the main study area, a check point was set up to the north. Minor pla ce name s wit hin the Re se rvoir study are a are carrie d on USGS t o pographi c maps of 1954, Allis on, Carracas , B u r n t M e s a , R os a, P i ne Ri ve r , a n d Go me z Ranch Quadrangles of the 7.5 minute series. Beyond these limits to the south and east, reference may be made to the Army Map Service, Aztec and Shiprock Quadrangles of 1954, 1:250, 000 scale. North of the Reserv o i r a re a , c o ve r a ge i s g i ve n b y A r m y M a p Service, Durango Quadrangle. State highway maps should be consulted for all road and town locations.

The author wishes to thank the above mentioned institutions, members of the field parties during the study periods, and, particularly, Alfred E. Dittert, Jr., of the Museum of New Mexico, who has been in charge of the archaeological field program. Thanks also are due James S. Findley, who freely gave advice and aid during the field work and the p re p ar a t i on o f t he ma nu s c r i p t , a nd W i l l i am C. Martin, who identified many of the plant s p e c i m e n s . B o t h a r e o f t h e U n i v e r s i t y o f N e w Me x i co . S te p he n D . D u r r a n t, f i e l d s u pe rvisor of the University of Utah Ecological R e s e a r c h e s d u r i n g t h e s u m m e r o f 1 9 6 0 , kindly offered use of some data. This manuscript was submitted during the summer of 1961 and remains, in January, 1963, essentially as at that time. However, the information on the ages of trees in the relict conifer stands, made available by F . W . E d d y , o f t h e M u se u m o f N e w M e x i c o , has been added since then, as have the definite re cords of mountain li on and p ro nghorn occurring within the Reservoir area.

Fig. 1. Pinyon-juniper growth on canyon sides overlooking the Pine River just above its junction with the San Juan. The topography is typical of the Junction Land Form.

One important source of biological information has appeared since the summer of 1961. Ecological Studies of the Flora and Fauna of Navajo Reservoir Basin was pub-

lished as Number 55 of the University of Utah Anthropological Papers, in October, 1961. Records from this work are not included here.

TOPOGRAPHY A land form consists of an area possessing a similar complex of physiographic features throughout its extent. Dittert, et al, (1961, pp. 18,20) have named three such land forms in and adjacent to the Reservoir area: the Arboles, Junction, and Blanco Land Forms. These terms are used here, but the Blanco Land Form has been expanded to cover somewhat more territory, as noted

below, and two new land forms, the Gallegos Mesa and the Waterflow defined. The Arboles Land Form extends north from just below the state border into Colorado. Wide valleys with sloping walls and rounded highlands are characteristic, although more rugged and angular forms appear locally. The highest altitude within

10

ECOLOGICAL DISTRIBUTION OF SOME VERTEBRATES

this area is approximately 8, 500 feet, atop the Piedra Peaks. The Junction Land Form lies south of the Arboles Land Form and consists essentially of a high, dissected plateau. Alternating, almost horizontal, strata of sandstones and clays of early Tertiary age are incised by deep and narrow, steep-sided canyons (Fig. 1). Altitudes range from approximately 5, 700 feet at the dam to some 6, 800 feet in the higher portions of the plateau. South of the Dam, the canyons broaden somewhat and relief lessens. This is the Blanco Land Form and, for the purposes of this paper, may be said to continue to the south of the San Juan River along the eastern border of the study area and westward along

and north of the river to the vicinity of Farmington. The Blanco Land Form is replaced to the south by rolling terrain with, in general, little relief. It is broken only occasionally by remnants of the plateau-forming strata and by cliffs or bluffs along drainage ways. Sands and clays are prominent features. This may be known as the Gallegos Mesa Land Form. North of the San Juan, northwest of Farmington, the terrain is somewhat similar to the Gallegos Mesa Land Form, but out-crops of rocks and clays are more common, the ground tends to be somewhat harder and rockier, and sand areas are less common. This may be known as the Waterflow Land Form.

VEGETATION Several recognizable vegetational units occur within the study area. These units are by no means clear-cut, invariable entities. They vary in composition and development spatially and often merge with one another to greater or lesser degree. Nevertheless, they do give a general picture of the environment at any one place. Pinyon-juniper This unit is characterized by the presence of the Colorado pinyon (Pinus edulis) and one or more of several junipers (Juniperus spp.). Associates throughout the study area may include Gambel oak (Quercus gambelii), mountain mahogany (Cercocarpus spp.), Utah serviceberry (Amelanchier utahensis), and skunkbush (Rhus trilobata). Understory plants may include big sagebrush (Artemisia tridentata), yuccas (Yucca spp.), and cane and pad cacti (Opuntia spp.)

sole representative of the genus. In more sheltered areas within an area extending from several miles south of the New Mexico- Colorado boundary, Rocky Mountain juniper (J. scopulorum) appears, becoming common north of the Colorado line. A few members of a third species of juniper (J. osteosperma) appear along the western edge of the study area. The pinyon-juniper unit also varies greatly in thickness of growth and in proportions of associates to be found with the "marker" species. Thus, in some areas, the tree forms are widely spaced and understory plants, such as sagebrush, relatively abundant. Elsewhere, crowding may preclude almost all under story plants. In a different Manifestation, junipers and pinyons occur very sparsely, with oak, mountain mahogany, Fendlera, and service-berry supplying most of the larger plants.

In general, the pinyon-juniper assoThe unit changes to some degree from ciation is found on canyon walls and slopes south to north. In the south, the one- seeded throughout the Junction Land Form (Fig. 1) juniper (J. monosperma) appears to be the

F i g . 2. Relict conifer stand in Benito Canyon near its junction with the Pine River.

12


and much of the Blanco Land Form of the New Mexican portions of the study area and on the lower slopes of high areas in Colorado, where it may merge with the ponderosa pine forests. Slight slopes on the plateau top south of the Colorado line, within the Junction Land Form, may be in pinyon-juniper, while immediately surrounding areas are in sagebrush. In several cases, where sagebrush occurs on gentle slopes in such situations, junipers and pinyons appear to be invading. South and west of the Junction Land Form, stands become rarer, usually depauperate in terms of associates, and almost entirely restricted to areas of relatively great re-lief.

were taken in 1959 by A. E. Dittert, Jr., F . W. Eddy, and J. J. Hester. The specimens were studied by Tom Lee, Laboratory of Tree-Ring Research, University of Arizona.

Relict Conifer

Sagebrush

Small (one to several dozen individuals) relictual populations of Douglas fir (Pseudotsuga taxifolia) and, to a somewhat lesser extent, ponderosa pine (Pinus ponderosa) appear sporadically throughout the New Mexican portion of the Junction Land Form (Fig. 2). Stands are associated, in most cases, with rather deep canyons and may appear near the head, within the length of the canyon, near the mouth, or, occasionally, in various combinations of these positions. In several cases, stands appear on northwesterly slopes along the San Juan and Pine Rivers proper, but most are in tributary canyons. A few scattered trees may occur unassociated with canyons. Some such stands of Douglas fir may recently have been reproducing successfully, but most entirely lack young trees. Associated plants may be only those typical of the pinyon-juniper unit or may include plants commonly associated with more mesic associations, such as wild cur -rent (Ribes aureum), choke cherry (Prunus virginiana), gray barberry (Berberis fendleri), and narrow-leaf cottonwood (Populus angustifolia). Corings of Douglas fir and ponderosa pine trees associated with Benito Canyon

Dates for the inner rings from Douglas fir trees were 1723, 1751, 1752, 1763, 1772, 1795, 1822, and 1846; those for two ponderosa pine trees were 1820 and 1841. No evidence was seen at this site of reproduction after these dates. Thus there is indicated rather regular reproduction occurring until the middle of the nineteenth century, with no successful reproduction since.

Big sagebrush (Artemisia tridentata) forms rather extensive, almost pure stands within the Junction Land Form on flats or on very gently sloping sites. To the south, within the eastern portions of the Gallegos Mesa Land Form, sagebrush may border the pinyon-juniper regions in a band that may be many miles wide (Fig. 3). The areas of individual stands decrease as one goes north of the Colorado line. In all cases, big sagebrush is the dominant plant; yucca and several species of grasses may appear in small numbers and, in the vicinity of arroyos or on river bottomland, greasewood (Sarcobatus vermiculatus), saltbush (Atriplex canescens), snakeweed (Gutierrezia lucida), and cocklebur (Xanthium saccharatum) may appear. Riparian In favorable areas along permanent water courses, in sloughs, and in moist, sheltered canyons may be found associations of cottonwoods (Populus wislizenii in the south and P. angustifolia within and north of the Reservoir), skunkbush, wild olive (Forestiera neomexicana), willows (Salix exigua and, less commonly, S. lasiandra), and box elder (Acer negundo) (Fi g. 4). The latter is restricted mainly or entirely to the Junction and Arboles Land Forms, as is the occasional appear-

F i g . 3. Sagebrush country south of the San Juan River. Photograph is from near Estrella, south of the study area.

Fig. 4. Two views of riparian habitat along the Pine River.

F i g . 5. Poorly developed ponderosa pine-Douglas fir habitat on flanks of Chimney Rock Mesa, west side of the Piedra River Valley.

Fig. 6. Cultivated land within the Arboles Land Form. View facing south across the Allison Valley toward Burnt Mesa.

INTRODUCTION

15

an te of ha wthorn s (Crata eg us s p p . ) . I n some a reas, poison ivy (Rh us rad ican s) ma y a ppear and a few examp les of sa lt cedar (Tama rix s p . ) occur in m ore open areas south of th e Colorad o bounda ry . Along irrig a tion d itches and sma ller strea ms, damp va lley s, occa siona lly on the flood p la in s of the la rger strea ms, and in sloug hs, an other typ e of d evelopm en t occurs, with or sepa ra te from th e ab ove. S edg es (particula rly S cirpus a cutus), h orse- ta ils (Eq uisetum spp .), ca ttails (Typ ha la tifolia), an d severa l grasses occur in va rious comb ina tion s. P ond erosa P in e - Doug la s fir In th e h igh er portion s of th e stu dy area, in Colora do, p oor to g ood stand s of pond erosa p in e and Doug la s fir app ea r. In the better d evelop ed a reas, Ga mb el oak , a spen (Pop ulus tremuloides), g ray ba rb erry , narrow lea f cotton wood, ' and a ld er (Aln us s p . ) also occur. Rocky Moun ta in jun ip er is commonly presen t. In less well d eveloped a reas, p lants more typ ica l of th e p iny on -jun ip er un it rep la ce th e ab ove sp ecies to a g rea ter or lesser d eg ree ( F i g . 5 ) . La rge ponderosa p in es a round build ings in the valley of the San Juan River east of Arboles may be remn an ts of h istorically larg er stan ds. Grasslan d Occurrin g a t g en era lly lower eleva tions than the sag ebrush , the gra ssland seems to show two facies. S outh of th e San

Juan River, grasses of several species form fairly dense, but low, stands with m any associates in the form of yucca (Yucca glauca), snakeweed, Mormon tea (Ephedra trifurca), pad cactus (Opuntia s p . ) and tumbleweed (Salsola kali). In sand dune areas and at lower altitudes, the grasses decrease in thickness of stand and the asso ciates become more common. This section of the grassland may meet with the sagebrush to the east in a very sharp line. With- in the Waterflow Land Form, the grassland appears poorer, both in thickness of stand and number of associates. Saltbush be -comes more common, but Mormon tea, snakeweed, and cacti decrease in numbers. In part, this may be a reflection of the soil, which is harder and rockier than that to the south. Cultivated Areas The bottomlands of the San Juan, Pine, and Piedra Rivers are much utilized for the growing of such crops as alfalfa, c l o v e r , fruits, and corn. A few localities on the plateau top of the Junction Land Form and much of the area around Arboles, Allison, and westward are also in crops, although these localities are not in the river valleys proper ( F i g . 6). In most situations, irrigation is necessary (small fields of corn and wheat have been grown without i r r i g ation on the plateau top, however). As a result of such cultivation, grassy vegetation and various crop plants supply animals a relatively recent habitat formerly absent or, at best, greatly re stricted.

CLIMATE Dittert, et a l (1961 ) ha ve brought togeth er clim a tic d a ta for th e immed ia te vicinity of th e R e s e r v o i r . I sohyeta l lin es run essentially northwest-southeast; the eighteen in ch isohyet fa lls just n orth of th e Reservoir lim its, and th e ten inch isoh yet crosses the area in the vicin ity of Bla nco. The April to

September period receives 55 -60 per cent of the total annual precipitation. Temperature and precipitation data for sta tions in or near the study area are given in Table I and have been taken from data presented in Climate and Man (Gittings, 1941; Hardy, 1941).

TABLE I

16

Temperature and Precipitation Records from Seven Stations Station

Temperature measured in degrees Fa hrenheit January Average

Annual Precipitation measured in inches

July Average

Maximum

Minimum

Aztec

26.8

73.7

104

-27

9.17

Bloomfield

26.8

74.7

106

-35

9.14

Fruitland

29.6

74.0

110

-21

6.76

Farmington

--

--

--

--

8.44

Rosa (near)

--

--

--

--

13.17

Shiprock

28.1

76.6

106

-18

7.59

Ignacio

21.8

67.5

101

-38

16.10

PRESENTA TION OF DATA To mak e clea r the g eographic distrib ution with in the study area and, insofar as kn own , th e preferred and lim iting ecological fea tures of th e amph ib ian s, r e p t il e s , and ma mma ls, th e followin g form of presentation ha s b een d ecid ed up on : (1 ) Wh ere little would be gained by compa rison s and con tra sts with other organism s, eith er b eca use of an in sufficiency of da ta or beca use of seem ing ly straightforward situa tion s, commen ts are g iven in the form of sp ecies accoun ts sta ting th e geographical rang es a s kn own with in th e study area, and d eta iling th e ecolog ica l cond itions as far as p ossib le. S ome ad d itiona l d a ta are given for th e ba ts beca use of th e pa ucity of such in forma tion in th e litera ture. (2 ) Wh ere compa risons are of par ticula r in terest, b ecause of the presence of closely rela ted sp ecies (b elong ing to the same g en us), g en eric a ccoun ts m ay be given following th e sp ecies a ccoun ts. I t is felt tha t by th is manner of pre sen ta tion , unm ean ing ful dup lication in sp ecies accoun ts may be avoided and greater insight into the dynamics of distribution gained,

reptiles are given in the same order as in Schmidt's Check List of North American Amphibians and Reptiles (1953); Hall and Kelson's Mammals of North America (1959) is followed for the mammals. For each species, record -stations of occurrence are given under the heading " L o c a l i t i e s . " Records from the literature are included when such fall within the study area or in the immediate vicinity (in genera] this includes all of La Plata and Archuleta Counties in Colorado, but a less well defined area in New Mexico). The record- stations are based on personal field work, on specimens in the University of New Mexico Collection of Vertebrates, and on records in the literature In the absence of a literature citation, the records are from the first two sources men tioned (all specimens collected personally and preserved are now in the University of New Mexico Collection of Vertebrates). A figure in parentheses following a locality refers to the number of specimens from that station.

ACCOUNTS OF SPECIES

AMPHIBIANS • Amby stoma tig rin um Green Tig er Sa lamand er In d ividua ls were seen or collected in farm land , p iny on- jun iper, sa gebrush, and gra ssland hab ita ts. Metam orph osed individ ua ls have b een seen in a rod en t b urrow exca va ted in to the a lm ost vertica l side of an arroy o and in a d eep cra ck form ed by water in a clay-wa lled cany on sid e. S pecim en s were collected from a cla y- bottom ed tank on the bottom of a canyon and from an earthen ca ttle tank in irrig a ted fa rm land . Wh ere sufficien t wa ter for b reeding occurs, m emb ers of th is sp ecies p robably are p resen t th roughout th e study a rea. Loca lities: COLORADO: La P la ta Co.: Durang o (Maslin, 19 59, p .'7 ) ; Allison (2 ). Arch uleta Co. (Maslin , 1 9 5 9 .p .7 ). NEW MEXI CO: San Juan Co.: Uliba rri Cany on, N 1/2 S ec. 25 , T 32 N, R 7 W, (sigh t record); 16 m i. S and 1 m i. W of Farm ing ton , S ec. 17 , T 26 N, R 13 W (11 ). Rio Arriba C o . : U e l l ' s Ca ny on, S ec. 26 , T 32 N, R 6 W (sigh t r e c o r d ) .

• Scaphiopus bombifrons Cope Cen tra l P la ins Sp adefoot Th is toad wa s collected on ly in juniper a nd sag eb rush , n ear g rea sewood g row ing along wa sh es. One in d ivid ua l wa s found after da rk , severa l h und red feet from a dirt ca ttle tank ; th e rema ind er were from mud at th e edge of the tank or, in a very few cases, from th e wa ter.

J.S.Findley has identified members of this genus by call at Allison, La Plata C o . , Colo. L o c a litie s : COLORADO: La Plata C o . : Oxford (Maslin, 1959, p.9). NEW MEXICO: Sa n Juan C o . : 2 mi. NW of Blanco (9).

• Bufo boreas Baird and Girard Boreal Toad Members of this species are available only from the northern checkpoint. They were found in quiet water near the mouth of Gordon Creek. Riparian vegeta tion borders the stream, with spruce forest nearby. The boreal toad probably exists somewhat further south, perhaps even to the northern portions of the main study area. Localities: COLORADO: Archuleta C o . : jct. Gordon Creek and Piedra River (6).

• Bufo woodhousei Girard Woodhouse's Toad Woodhouse's toad is widespread throughout the study area. One specimen was taken from a group of Bufo boreas in chorus in an area of spruce (Picea engelmannii) and riparian vegetation; other specimens were secured from all vegetational types represented in the study area, although only in the sparser areas of ponder -

18


osa p ine -Doug las fir f o r e s t . Th e only limit a tion ap pea rs to b e the la ck of available wa ter –th e d ryn ess of the summ er of 1960, wh en m ost field work wa s done in the south, ma y a ccoun t for appa ren t ab sence in some a reas, since ra in pools were unavailable for collectin g purp oses. Th e few choruses loca ted would seem to ind ica te a preference for wa ter with little vegeta tion. At Allison , for example, though n um erous irriga tion d itch es and heavily veg eta ted tank s were ava ilab le, th e breeding ch orus a nd ind ivid ua ls in am p lexus were found only in a tank which had no noticeable vegeta tion in 1959 , and b ut little the follow in g y ea r. I n g en era l, ind ivid ua ls located in wa ter at other sites were in d irt tanks or strea ms with little vegeta tion. Loca lities: COLORADO: La Plata Co. Rio Florida near Durang o (Maslin, 1959, p . 13 ); 11 m i. S of Durang o (Maslin, 1959, p . 14 ); Allison (17 ). Archuleta C o . : jct. Gord on Creek and P iedra River (1); Piedra River, upp er camp ground NW of Chimney Rock (Maslin, 1959, p. 14); Deep Canyon (6); Yellowjacket turn off, Colo. 151 (1); vicinity Allison, S ecs. 14 and 23 , T 32 N, R 6 W(3). NEW MEXI CO: San Juan Co.: near Pine River, S ec. 7 , T 30 N, R 7 W (2 ); 2 mi. NW of Bla nco (9 ); ab out 3 m i. E and 3 mi. S of Fa rm ing ton (2 ); ab out 5 m i. W and 2 mi. S of Bloomfield (6 ); Ga lleg os Cany on , Sec. 9, T 28 N, R 12 W (1 ). Rio Arriba Co,: 2 mi. S of Rosa (1 ).

Tadpoles, almost ready for metamorphosis, were collected from meadows near the upper Piedra River in late June. The call of this species was heard from marshes at Blanco, San Juan Co., New Mexico, several hours after dawn, but none was seen. Localities: COLORADO: La Plata C o . : 10 mi. S of Durango (Maslin, 1959, p. 17); 1 1/2 mi. W Allison (1). Archuleta C o . : Gordon Creek near jct. with Piedra River (la r v a e ); Pagosa Springs (Maslin, 1959, p. 16); vicinity Allison, Secs. 14 and 23, T 32 N, R 6 W (21).

• Rana catesbeiana Shaw Bullfrog No evidence of the bullfrog, widely introduced in the Southwest, was found north of the Dam site. South of the Dam site, one specimen was found in a heavily vegetated backwater area of th e San Juan R i v e r . Riparian vegetation and croplands are in the immediate vicinity, with pinyonjuniper on the canyon walls. An individual was seen several times in a large dirt cattle tank at the edge of Gallegos Canyon, some six miles south of the San Juan River°. The tank is fairly deep and with a fair amount of submergent vegetation. Localities: NEW MEXICO: San Juan Co.: about 3 mi. N (by road) of Archuleta (1).

• Pseudacris nigrita LeConte Ch orus Frog

• Rana pipiens Schreber Leopard Frog

In the vicinity of Allison, the chorus frog wa s heard freq uently a lon g irrigation ditches and in those tanks which supported g ood growth s of aq ua tic veg eta tion. The ma jority of specim en s were collected at n igh t. On e sp ecim en, however, was found d uring th e day tim e on a freq uently watered la wn.

Leopard frogs are not uncommon in the irrigation areas, natural sloughs, and other areas of permanent water which support vegetation near the water's edge. L o c a litie s : COLORADO: La Plata Co.: 20 mi. N of Hermosa (Maslin, 1959,

ACCOUNTS OF SPECIES

19

p. 19); 8 mi. NW of Hesperus (Maslin, 1959, p . 19 ); 1 0 m i. S of Duran go (Ma slin, 1959, p . 19 ); vicin ity Columb in e Ra nger Station (5 ), Durang o (Maslin, 195 9, p . 19); Rio Florida, near Durango (Maslin, 1959, p. 19); Allison (2 ). Arch uleta C o . ; jct. Gordon Creek an d P ied ra River (1 ); P ied ra River

upper campground N W of Chimney Rock (Maslin, 1959, p. 19); vicinity Allison, Secs. 14 and 23, T32 N, R 6 W (1). NEW MEXICO: San Juan Co.: Pine R i v e r , NW 1/4, Sec. 7, T 30 N, R 7 W (1); 4 mi. N and 1 mi. E of Waterflow (1).

REPTILES • Chrysemys picta Schn eider Pa in ted Turtle Th e pa in ted turtle m ay occur in p erman en t stream s with in the main study a rea. No sp ecim en s a re a va ilab le from within th e Reservoir b ut th ere are app arently reliab le rep orts of th e presen ce of a turtle, p resumab le of th is species, in the Piedra River nor th of Arboles an d in the San Juan south of th e Jun ction Lan d Form. One sp ecimen wa s p ick ed up from a road west of th e stud y a rea by A . E . D i t t e r t , J r . ; a small strea m was n ea rby . Loca lities: COLORADO: La Plata C o . : 5 m i. N of Durango, An ima s River d ra in age (Ma slin , 1959 , p.23 ); 3 mi. E of Oxford, Colo. Rt. 172 (1 ).

• Crotaphy tus colla ris Sa y Colla red Liza rd Th e collared liza rd was most often seen on or nea r rock s in p in yon -juniper or, occa siona lly , sa geb rush h ab itat. On severa l occasion s, y oung liza rd s were cap tured or seen a t d ista nces of up to severa l hun dred feet from rocky areas usua lly in sag eb rush , but in on e instance in ripa rian ha b ita t. P iny on -jun iper was n ea rby in th ese cases. On e a dult and one juven ile an ima l were tak en in a clay- hill area of scattered pinyons and junipers. In th is la tter ca se, th ere were n o rocks for a m ile or more from the p oin ts of capture; th e ad ult liza rd was snap -trapp ed from a

rodent burrow opening and the immature animal was taken from beneath wood debris. In the Gallegos Canyon area, these lizards inhabit rock outcrops in a marginal pinyon juniper area mixed with much grass and sagebrush. Localities: COLORADO: La Plata C o . : near Bondad (Maslin, 1959, p . 2 6 ). Archuleta C o . : Arboles (1). NEW MEXICO: San Juan C o . : Pine R i v e r , N E 1/4 Sec. 18, T 32 N, R 7 W (1); extreme SE corner Sec.29, T 31 N, R 7 W (1); Pine River, NE 1/4 Sec. 7, T 30 N, R 7 W (1); Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W (2); near jct. Sambrito Creek and San Juan River (1); Pine River Canyon, Sec. 20, T 3 1 N , R 7 W ( 1 ) ; S e c . 29, T 3 0 N , R 8 W , 5,800' (1); jct. San Juan and Pine Rivers, N W 1/4 Sec. 17, T 30 N, R 7 W (2); Gallegos Canyon, Sec. 9, T 28 N, R 12 W (1); about 3 mi. E and 3 mi. S of Blanco, Sec. 34, T 29 N, R 9 W, 5800' (1); 3 1/2 mi. E and 7 mi. S of Bloomfield, Sec. 32, T 28 N, R 10 W (2). Rio Arriba Co.: extreme SE corner Sec. 22, T 32 N, R 6 W (1).

• Holbrookia maculata Girard Lesser Earless Lizard The lesser earless lizard seems to be associated with sandy portions of the grassland south of the San Juan R i v e r . It is doubtful that its range extends north of the river within the river within the study area.

22


an d 3 m i. S of Blan co, S ec. 34 , T 29 N, R 9 W, 58 00' (4 ); 16 m i. S and 1 m i. W of Fa rm ing ton , Sec. 17, T 26 N, R 13 W(1); 2 1 /4 m i. N an d 1 1 /4 m i. E of Waterflow, S ec. 28 , T 30 N, R 1 5 W (3 ); 5 1/2 mi. N an d 1 1 /2 m i. W of Wa terflow, Sec. 12, T 30 N, R 16 W (3 ); 3 1/2 m i. E a n d 7 m i . S of Bloomfield, S ec. 32 , T 28 N, R 10 W (3 ); 1 m i. E and 9 m i. S of Bloomfield, Sec. 11 , T 27 N, R 11 W (1 ); ab out 4 mi. S of Ga lleg os S tore, n ear Ga llegos Ca nyon (I ).

pine areas in the north (there is a sight record from near the San Juan River, two miles west and one mile north of Juanita, Archuleta C o . , C o l o . ) and throughout t he flatter areas of pinyon-juniper and sage brush in the more southerly portions of the Junction Land F o r m . No specimens were taken within those portions of the study area south of the Junction Land Form, but, as they are known to occur south of the study area in habitat similar to that of the Gallegos Mesa Land Form, they probably are present throughout the southern por tions of the study area.

• Urosa urus orna tus Ha llowell Tree Lizard

Nowhere were members of this species recorded from riparian situations or from cropland and they appeared absent from situations of strong topographic relief.

Ca ry (19 11, p .26 ) reported observ ing th is liza rd a t Arb oles, Arch uleta C o . , Colo. No mem bers of th is sp ecies were seen or collected and it seem s lik ely th at this was a m isid en tifica tion , p erhap s ba sed upon a young _______ S celoporus und ulatus. If, h owever, th e record is g ood, th en it must be a ssum ed tha t the an ima l is extremely rare or ha s van ished from th e Arb oles and Junction Land Form s. Alth ough not seen imm ed ia tely south of th ese a reas, more work would be n ecessary to a llow a definite sta tem en t a s to its presen ce or absence.

• Ph ryn osom a corn utum (Harlan) Texas Horn ed Liza rd Ma slin (195 9, p .37 ) cites Cope as listin g P ag osa , Arch uleta C o . , Colo., as a loca lity for th is sp ecies. I t seems reasonab ly sa fe to con clud e on th e grounds of kn own d istrib ution and hab ita t that this record rests up on an escap ed p et, a misla beling , or a m isid en tifica tion.

• Ph ryn osom a d oug la ssi ( B e l l ) Short Horn ed Liza rd Alth ough seem ing ly n ot common, th is liza rd was foun d in th e op en ponderosa

Small, apparently f i r s t- y e a r individuals were first collected during the first week of August, 1959. L o c a litie s : COLORADO: La Plata Co. (Maslin, 1959, p . 4 0 ) . Archuleta C o . : 2 mi. N of Chromo (Maslin, 1959, p.40); SW 1/4 of SE 1/4 Sec. 10, T 32 N, R 5 W (1). NEW MEXICO: San Juan Co.: SW 1/4 Sec. 8, T 32 N, R 7 W (1); E side NW 1/4 Sec. 10, T 32 N, R 6 W (1); NW 1/4 Sec. 22, T 32 N, R 6 W (1); near San Juan River, Sec. 3, T 31 N, R 6 W (1); near mouth Cotton wood Canyon, SE 1/4 Sec. 17, T 31 N, R 6 W (1); Pine River R d . , SE 1/4 Sec. 17, T 31 N, R 7 W (1); Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W (1). Rio Arriba Co.: San Juan River, Sec. 27, T 32 N, R 6 W (1).

• Cnemidophorus tigris Baird and Girard Western Whiptail The western whiptail appears to be limited in distribution to the area south of the Junction Land Form, although perhaps overlapping to a slight degree into this region in a few places. It has been taken in the sparser portions of the lower pinyon -

ACCOUNTS OF SPECIES

juniper zone, in grassland, and in marginal ripa rian situa tion s. With in the distribu tiona l a rea of C. in ornatus, a s now known, C. tigris ap pea rs to b e lim ited to wash areas an d the b ordering a reas of rock out-crops an d b luffs. In th e western portions of the study area , north of the San Juan River, wh ere C. inorn a tus ha s n ot been found, C. tig ris is foun d in b oth th e typ es of areas d escrib ed ab ove and in a reas of lesser relief an d thus may f i l l th e nich e of C. inornatus in th is reg ion . The western whiptail has been taken in reg ions of sandy and of rock substrata. Wh en associa ted with th e la tter, it was seldom foun d a mon g b ould ers, but rather in a reas of exposed bedrock with small a reas of soil a nd sa nd. Th is liza rd may b e a ctive during m id-d ay, a fter m ost other sp ecies have r e t i r e d . In th is resp ect, it approaches the sched ule of C. in orna tus, th ough usually ap pea rin g somewha t later in the morning and remaining active somewhat later in the a fternoon . Loca lities: NEW MEXI CO: San Juan C o . : a b out 3 m i. E a nd 3 m i. S of Farmington (2 ); Ga lleg os Cany on , Sec. 9, T 28 N, R 12 W (10 ); Kutz Cany on a t jct. with US 44 (1 ); ab out 3 m i. E a nd 3 m i. S of Bla nco, Sec. 3 4, T 29 N, R 9 W, 5800' (1); 2 1 /4 m i. N an d 1 1 /4 m i. E of Waterflow, S ec. 28 , T 30 N, R 1 5 W (3 ); 5 1/2 mi. N an d 1 1 /2 m i. W of Wa terflow, Sec. 12, T 30 N, R 16 W (2 ).

23

tends into the more open areas of pinyonjuniper, riparian, and low streamside vegetation. Although commonest on flat or gently sloping tracts, it occurs for short distances beyond such habitats into boulder fields at cliff bases, debris along slopes of small valleys, and, occasionally, onto steep canyon walls. Areas of heavy plant growth, including pinyon-juniper, and of finely dissected topography appeared uninhabited by this species. L o c a litie s : COLORADO: La Plata C o . : Allison (1). Archuleta C o . : Carracas- Arboles R d . , NE 1/4 of SW 1/4 Sec. 17, T 32 N, R 4 W (1). NEW MEXICO: San Juan Co.: near jct. Sambrito Creek and San Juan River (2); Pine River Canyon, Sec. 20, T 31 N, R 7 W (3); E side NW 1/4 Sec. 10, T 32 N, R 6 W (1); SW 1/4 Sec. 11, T 32 N, R 6 W (2); Sambrito Creek, SW 1/4 Sec. 10, T 32 N, R 6 W (1) ; Sambrito Creek, S 1/2 Sec. 15, T 32 N, R 6 W (1); San Juan River, NW 1/4 Sec. 22, T 32 N, R 6 W (4); mouth of Benito Canyon, NW 1/4 of NW 1/4 Sec. 29, T 32 N, R 7 W (2); NW 1/4 of SW 1/4 Sec. 4, T 30 N, R 7 W (1); Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W(2); jct. San Juan and Pine R i v e r s , NW 1/4 Sec. 17, T 30 N, R 7 W (1); 1/2 mi. S of Navajo Dam site (1); 2 mi. NW of Blanco (1); about 3 mi. E and 3 mi. S of Blanco, Sec. 34, T 29 N, R 9 W, 5800' (2). Rio Arriba C o . : Rosa (1); SE 1/4 Sec. 13, T 32 N, R 6 W (4); SW 1/4 Sec. 23, T 32 N, R 6 W (1).

• Cnemidophorus inornatus Baird Little Whiptail • Cnemidophorus velox Springer P la teau Wh ip ta il Th e p la tea u wh ip ta il was found to in hab it th e Jun ction Land Form, overlapp ing sligh tly in to th e Bla nco and Arboles Land Form s. I t is found ma in ly within open b order a rea s, in sag eb rush m ost commonly, b ut seld om furth er than several hundred ya rd s from oth er, th icker vegetation or rocky outcrops. I ts rang e a lso ex-

The little whiptail was found in grassland areas south of the San Juan R i v e r . At one collection station, in an area of sharp transition between grassland and sagebrush, a few individuals were taken from sagebrush, but always within a few hundred yards of grassland. The lizards were common on the higher, sandy ridges where shrubby vegetation (parti cularly Ephedra) was common; they were

26


• P ituoph is ca ten ifer ( B l a i n v ille ) Gopher Snake

Localities: NEW MEXICO: San Juan C o . : NE 1/4 Sec. 24, T 32 N, R 7 W (1).

Th e g oph er snak e was the least re stricted ecolog ica lly of an y of the snakes found in th e stud y a rea. S pecimens were ta ken from th e lower levels of the ponderosa p ine- Doug la s fir forest, from pinyon- juniper, sag eb rush , fa rm la nd, and riparian habitats. Most specim en s are from a reas which are p redom inan tly non rocky and possess only g en tle slop es.

• Lampropeltis doliata (Linnaeus) Milk Snake

Loca lities: COLORADO: Archuleta C o . : P ag osa (Maslin, 195 9, p. 62); 0.4 mi. (b y road ) S of th e jct. of Colo. 151 and US 16 0 (1 ). NEW MEXI CO: Sa n Juan Co.: b ounda ry between S ecs. 9 and 16, T 32 N, R 6 W (1 ); NW 1/4 S ec. 22 , T 32 N, R 6 W (1); S E 1/4 of S E 1 /4 Sec. 26 , T 32 N, R 7 W (1); W sid e P in e River, opposite Wool Can -yon (1 ); Ulib arri Cany on , N 1 /2 Sec. 25, T 32 N, R 7 W (1 ); n ea r m outh Cottonwood Canyon, S E 1/4 S ec. 17 , T 31 N, R 6 W (1); Pine River, S W 1 /4 Sec. 8 , T 30 N, R 7 W (1); Pine River, NE 1 /4 of NW 1 /4 S ec. 7, T 30 N, R 7 W (1 ); Sa n Juan River, just S of confluence with P in e River (1 ); Wa t erflow (1); Gallegos Ca nyon, S ec. 9 , T 28 N, R 12 W (1); 1 1/2 m i. W an d 7 m i. S of Bloomfield, Sec. 4, T 27 N, R 11 W (1 ). Rio Arriba C o . : S ec. 22, T 32 N, R 6 W (1).

• Masticophis taeniatus (Hallowell) Desert S triped Whipsnake On ly one sp ecimen of the d esert strip ed wh ip snak e wa s en countered within th e stud y a rea . Th is ind ividual was caught about midmorning among pinyons and juni p ers with in th e Junction Land Form. Sagebrush is nearby as an understory plant and, a few h und red feet a way , a north slope sup p orts h ea vy growths of m ountain mahogany am idst the p in yon s and junipers; smaller am oun ts of Utah serviceb erry and Gambel oak app ea r. Th e loca lity shows moderate r e l i e f ; a lth ough th e sub stratum is pre d om in a tely of cla y, sand stone outcrops ap p ea r nea r by .

A single specimen, which escaped before preservation, was taken near the mouth of Deep Canyon, Archuleta C o . , Colo., on the morning of 6 July 1959. The snake was found beneath a decaying log in an area of ponderosa pine and Gamb el oak. Rocky Mountain juniper and skunkbush also occur in the area; Douglas f i r is present a short distance up-canyon. The snake was examined carefully after capture and the identification to species is considered certain despite the later loss of the specimen,

• Crotalus viridis (Rafinesque) Western Rattlesnake This snake is relatively rare within the study area. The northernmost record is from the edge of a small stream with a growth of narrow-leaf cottonwood along its mar -gins. Ponderosa pine and some Douglas fir cover the nearby slopes. Two specimens are available from the pinyon-juniper unit, one from among the rocks of a canyon wall, the other from the relatively flat plateau top separating the San Juan and Pine R i v e r s . In the latter case, rather large amounts of shrubby growth (Gambel oak, mountain mahogany, e t c . ) are present. The sole specimen from south of the Junction Land Form was found coiled beside a snap trap in the damper portion of a sedge bed on the east margin of Gallegos Canyon. Pinyon-juniper, sagebrush, and grassland intermingle to some degree in this region.

ACCOUNTS OF SPECIES

27

A very sparse growth of cottonwood and wild olive is found in th e vicin ity. Loca l in hab ita n ts seem to consider th e ra ttlesnak e r a r e . I t seem s p robab le that it rea ch es little further n orth in the vicinity. Ma slin (195 9 ) does n ot report re-cord s from th e two Colorad o coun ties in to wh ich the study area extend s.

Localities: COLORADO: Archuleta C o . : 4 mi. S (by road) of the jct. of Colo. 151 and US 160 (1). NEW MEXICO: San Juan Co.: E wall of canyon of Pine R i v e r , oppo site mouth of Wilmer Canyon, SE 1/4 of SE 1/4 Sec. 19, T 32 N, R 7 W (1); Pine River R d . , SE 1/4 of SE 1/4 Sec. 26, T 32 N, R 7 W (1); Gallegos Canyon, Sec. 9, T 28 N, R 12 W (1).

MAMMALS • S orex vag ran s Ba ird Va gra n t Sh rew On e sp ecimen was trapp ed on 6 July 19 59, by Clyde J. Jones, in a _Microtus m on ta nus run wa y through th ick sedg es (S cirp us a cutus) in termixed with som e grasses. P ond erosa p in e, p iny on , and jun ip ers occur in th e g enera l a rea . Warren (1942) reports that this shrew is found th rough out pra ctica lly th e whole m oun ta in ous reg ion of Colorado to an elevation a s low a s 7, 00 0 feet. Loca lities : COLORADO:_ Arch uleta C o . : 2 m i. E and 1 /2 mi. N of Ch imn ey Rock ( 1 )• • Myotis y uman en sis (H. Allen ) Yuma My otis Un til comp letion of a recen t study (Ha rris and Find ley , 1962 ) b ased on the necessity for id en tifica tion of two sp ecimens from with in th e study a rea, ba ts of th is typ e were a ssign ed to th e sub sp ecies M. lucifug us ph asm a Miller and Allen . Th e study has resulted in their placement within the present sp ecies. Th e two sp ecim ens were tak en from over an ea rth en ca ttle tan k, one on 11 June an d the second on 16 Jun e. Th e general area is on e of crop lan ds; th ose tra cts n ot in crops a re in sag eb rush .

Both animals were pregnant f e m a l e s . In the earlier capture, a single embryo was just discernible, and the individual taken on 16 June had one embryo measuring 12 mm. (Crown X rump). Localities: COLORADO: La Plata C o . : Allison (2).

• Myotis evotis (H. Allen) Long eared Myotis Specimens from the study area were taken over a small tank formed by the dam ming of an intermittent stream. The vege tation is that of the ponderosa pine -Douglas fir unit, with the former tree by far the more common. A small amount of aspen is near -by. Gambel oak and junipers are common. The specimens were taken on 22 July 1960. All were females; one was im mature. Localities: COLORADO: Archuleta C o . : Deep Canyon (3).

• Myotis volans (H. Allen) Long legged Myotis The long- legged myotis is known from ponderosa pine -Douglas fir forest and from riparian growth in the canyon of the

F i g . 7. Roost of Tadarida molossa.

L o ca l it i es : NEW MEXICO: San Juan Co.: ca ve n ea r P in e River, SE 1 /4 Sec. 6, T 30 N, R 7 W (2 ).

A very young female was captured on 7 July. Lactating females were collect ed on 14 and 19 July; apparently nonlactating females on 14, 19, 22, and 27 July. Males were collected on 19 and 27 July.

• Antrozous pallidus (Le Conte) Pallid Ba t

Localities: COLORADO: Archuleta C o . : Deep Canyon (1). NEW MEXICO: San Juan Co.: Marcelo Lucero place, Pine River Canyon (2); W side of Todosio Can -yon (1); Gale Wash, 4 mi. E and 2 mi. S of Bloomfield (3); about 3 mi. E and 3 mi. S of Farmington (5); 16 mi. S and 1 mi. W of Farmington, Sec. 17, T 26 N, R 13 W (1).

The pallid bat may be presumed to be widespread throughout the southern portions of th e stud y a rea , b ecom ing ra re to the north. On e sp ecimen was tak en in p onderosa pineDoug las fir forest; others cam e from well d evelop ed p iny on-jun iper stand s, marginal p inyon-jun iper with m uch sa ge -brush, and from g ra ssland . La ck of a va il-ab le roosting sites p ossib ly could be a lim it ing factor, but rela tively few area s are without potential sites within flying distance. Th e one roost found in the study area wa s b eh ind a th in slab of rock on a cliff face. Ava ilab le space wa s about two inches at the wid est.

• Tadarida molossa ( P a l l a s ) Big F r e e t a i l Bat On e of the few known roosts of this large bat was in the Reservoir area ( F i g . 7). Two large rock shelters, a short distance below the lip of the canyon wall of

ACCOUNTS OF SPECIES

th e P in e River an d within a few h undred ya rd s of ea ch oth er, supp orted a total of some th irty ba ts (estima ted ). Both shelters a re a pproxima tely 10 0 feet ab ove the Recent a lluvium terra ce of th e P ine R i v e r . The cany on wa lls in th is section are very steep. Th e shelters a re d ifficult of a ccess, ropes b eing required for sa fe en try to one. Both fa ce app roxima tely east. Th e ba ts were in crevices in the ceiling s of the sh elters. Th e crevices are long (th irty feet or m ore for on e; thirty to forty feet for the oth er), d eep (six feet or m ore for on e; an estimated eigh t to ten feet for th e oth er), a nd a t a h eigh t of about six to eig h t feet a bove the floors of the shelters. A slig h t ang ling in lea ving th e roost would p rovide th e ba ts with th irty feet or more of free f a l l . I n b oth ca ses, th e crevices curved so a s to b lock view of th eir full vertical exten t.

31

Within the study area, this rabbit is concentrated north of the Colorado state line. It is common in ponderosa pine Douglas f i r , in those areas of pinyon -juni per which also support good stands of Gambel oak, and in riparian habitat in that region. Two specimens have been taken in the New Mexican portion of the study area. One of these was collected from dense sage brush in a small valley with perman ent water; mi xed with the sagebrush are good stands of grass, willows, narrow - leaf cottonwood, squawberry, and some juniper. Irrigated fields are nearby. The other specimen was collected in a very dense stand of pinyon -juniper. Both are from the Junction Land Form, no t far south of the Colorado state line.

V eg eta tion in th e vicin ity is pinyonjun ip er, well- d evelop ed on ly on the flats ab ove th e cany on wa lls; the wa lls them selves supp ort fa ir numb ers of juniper, a few p iny ons, and m uch b rush (m ountain ma hog any , e t c . ) . Ripa ria n g rowth and c ultiva ted field s are on th e b ottomlands of th e cany on. A few relict con ifer stands exist in th e g enera l vicin ity .

L o c a litie s : COLORADO: Archuleta C o . : NE 1/4 of SE 1/4 Sec. 18, T 32 N, R 4 W (1); Sec. 23, T 32 N, R 4 W (2); Sec. 18, T 32 N, R 4 W (1); N 1/2 Sec. 22, T 3 2 N , R 4 W ( 1 ) ; 21/2 mi. Sand 1 m i . W of Chimney Rock (1); Deep Canyon, 4 mi. S and 1/2 mi. W of Chimney Rock (5). NEW MEXICO: San Juan Co.: Sambrito Creek, SE 1/4 of SW 1/4 Sec. 15, T 32 N, R 6 W (1); Pine River R d . , W side Sec. 3, T 31 N, R 7 W (1).

A l l collected ind ivid ua ls were fema les. A sp ecim en tak en on 30 June was ca rry ing an em bry o (crown X rump length, 33 mm .). Oth ers collected th e same date an d on 18 July ha d n o emb ry os.

• Sylvilagus auduboni (Baird) Desert Cottontail

Loca lities: NEW MEXICO: San Juan Co.: P ine River Cany on nea r Todosio Can y on (7 ). • Sylvilagus nuttalli (Bachman) Nutta ll' s Cotton ta il Nutta ll' s cotton ta il is primarily an an ima l of th e pon derosa p in e -Douglas fir un it, but extends to lower eleva tions in ripa rian an d the d en ser p iny on -juniper ha b ita ts.

In keeping with its common name, this rabbit is most plentiful in the more xeric portions of the study area. It was observed in grassland, sagebrush, open pinyon- juniper, and brushy stream or wash vegetation. In the more open habitats, in dividuals were most common in or n e ar rocky or dissected regions, seldom being observed in flat, open sagebrush or grass land. Few specimens were collected in the southern portions of the area, but were

32


seen at most stations except those of little top og raph ic r e l i e f . Loca lities: COLORADO: La Plata _ C o . : Allison , E sid e NW 1 /4 Sec. 15, T 32 N, R 6 W (1 , sk ull p ick up ). NEW MEXICO: San Juan Co.: NE 1/4 Sec. 12, T 3 2 N, R 7 W (1 ); S W 1 /4 S ec. 34,T 32 N, R 7 W (1); NE 1/4 of SE 1/4 Sec. 5, T 30N, R 7 W (1 ); Ulibarri Cany on , N 1 /2 Sec. 25, T 3 2 N, R 7 W (1 ); NW 1 /4 S ec. 9, T 32 N, R 6 W (1 ); 2 m i. NW of Blan co (1 ); Fruitla nd (Nelson , 1909 , p. 23 2 ); Aztec (Nelson, 19 09, p .232 ); Bla nco (Nelson , 1909, p.232); Ca nyon Blan co (Nelson, 1909 , p .232). Rio Arrib a C o . : Dulce (Nelson , 1 909 , p.232).

• Sy lvila gus Gray Cotton ta ils Th e d istrib utions of Nuttall's cotton ta il a nd th e d esert cotton ta il overlap to some d eg ree. With in th is zone of sym patry, Nutta ll' s cotton ta il tend s to in habit the d en ser veg eta tion ty pes and th e desert cotton ta il m a in ly th e m ore open a reas. In the Sa mbrito Creek d ra in age south of the Colorad o lin e, for examp le, Nutta ll' s cottontail was found in the dense vegetation along the strea m, wh erea s th e desert cottontail was ta ken from nea rby sa geb rush fla ts. The zone of overlap is narrow, p robab ly little if any g rea ter tha n ten m iles in wid th, and appears cen tered a few m iles south of th e New Mexico-Colorad o sta te lin e. The results of th is study would seem to bear out the sta tem en t of Warren (194 2, p .271) that " . . . s o m e t i m e s (th e) two sp ecies are found at p ra ctica lly th e same l o c a l i t y . "



Lepus ca liforn icus Gray Black -tailed Jack Rabbit

In the northern portions of the study a rea, th e b la ck -ta iled ja ck rabb it was seen, with few excep tions, on ly in a reas of sage b rush an d was com mon th ere. Records of sigh ting s from th e study a rea reveal none

from the Piedra Valley north of approxi mately Arboles; in the San Juan Valley to the east of Arboles, however, there are records almost to Cato. It is probable that the range of these animals extends to a grea ter or lesser extent into pinyon -juniper and perhaps occasionally into lower ponderosa pine f o r e s t . To the south, it was observed in both sagebrush and grass - land, although more common in the f o r m e r . Localities: COLORADO: La Plata C o . : Ft. Lewis (Warren, 1942, p.262); Bayfield (Warren, 1942, p. 262). Arch uleta C o . : NW 1/4 Sec. 23, T 32 N, R 6 W (1). NEW MEXICO: San Juan C o . : E 1/2 T 31 N, R 8 W (1); Sec. 12, T 30 N, R 8 W (1); Aztec (Nelson, 1909, p.145); Fruitland (Nelson, 1909, p. 145); Canyon Blanco (Nelson, 1909, p. 145).

•

Eutamias Minimus (Bachman) Least Chipmunk

The least chipmunk, absent from the study area proper, was common, along with the Colorado chipmunk, near the junc tion of Gordon Cre ek with the Piedra Rive r . Warren (1942, p. 146) mentions that this animal ranges down to the pinyon and juniper zone and that it has been taken with the Colorado chipmunk. Thus it may be presumed that its lower limits are near the study area's boundaries. Localities: COLORADO: La Plata C o . : Florida (Howell, 1929, p. 50). Archuleta C o . : Gordon Creek near jct. with Piedra River (4); Navajo River (Howell, 1929, p.50); Chromo (Howell, 1929, p. 50 ).

•

Eutamias quadrivittatus (Say) Colorado Chipmunk

The Colorado chipmunk is common in the ponderosa pine -Douglas fir forest where thickets, fallen logs, and other de bris provide ample cover, and in those

ACCOUNTS OF SPECIES

p ortions of th e p iny on- jun ip er a nd relict con ifer un its wh ere rock outcrops occur; it appea rs to b e absen t from a ll b ut the th ick est growths of n on-rocky p inyon -juni p er a rea s. In th e more south erly portions of th e stud y a rea , th is ch ipm unk lives a-long h igh cliffs an d a mon g rock d eb ris even wh ere the p iny on-jun iper un it is extremely spa rse, with sagebrush and g ra sses prevalen t. Th e ma jor fa ctor lim iting its geo g raph ic d istrib ution seem s to b e the availab ility of cover (th ough it seems to be absent from even th e th ickest ripa rian c o v e r ) . The an ima ls app ear n oticeab ly m ore wary in reg ions b elow pon derosa p in e- Douglas f i r vegeta tion than in th e h igher life- zones that p rovide b etter overh ead cover; th is may well b e in response to th e grea ter dan ger, pa rticula rly from b irds, in th e m ore open a reas. The Colorado chipmunk occurs with th e least ch ip mun k in th e sp ruce forest of th e upper P ied ra R i v e r . In the south there is eq ua lly close p roxim ity to the antelope g roun d sq uirrel. Loca lities: COLORADO: La Plata C o . : Ba yfield (Howell, 1929, p. 83); Bon dad (Howell, 1929, p.83); Florida (Howell, 1929, p . 8 3 ) . Arch uleta C o . : Gordon Creek near jct. with P ied ra River (4 ); Pag osa Sp rings (Howell, 1929, p. 83); Deep Canyon (6 ); S tollsteimer Creek n ea r mouth Deep Can -y on (1); N side Sa n Juan River, ab out 1/2 m i . E of Gato (1); 2 m i. W and 1 m i. N of Juan ita (2 ); Chromo (Howell, 1929, p. 83). N EW MEXI CO: San Juan Co.: Ben ito Can-yon , NE 1 /4 of NW 1/4 S ec. 29, T 32 N, R 7 W (1 ); NW 1 /4 of SW 1/4 S ec. 4, T 30 N, R 7 W (2); 4 m i. S and 1/2 mi. E of Allison (1 ); P in e River Cany on, Sec. 20, T 31 N, R 7 W (3 ); jct. San Jua n a nd Pine R i v e r s , NW 1/4 Sec. 17, T 30 N, R 7 W(1); P ine R i v e r , NW 1/4 S ec. 7 , T 30 N, R 7 W (8); P ine River, S W 1/4 S ec. 8, T 30 N, R 7 W (1); 1/2 m i. S of the Na va jo Dam site (2); about 3 m i. E an d 3 m i. S of Blan co, S ec. 34, T 29 N, R 9 W, 5800'(1); La rg o Can yon (Ba iley, 1931, p. 85); a b out

33

3 mi. E and 3 mi. S of Farmington (4). Rio Arriba C o . : SE 1/4 Sec. 13, T 32 N, R 6 W, 6400' (1); Uell's Canyon, SE 1/4 Sec. 26, T 32 N, R 6 W (1) ; Dulce (Howell, 1929, p.83); about 1 mi. N of Bancos Can- yon (1); near mouth of Bancos Canyon (1).

•

Marmota flaviventris (Audubon and Bachman) Yellow -bellied Marmot

Yellow -bellied marmots have been seen by myself and other members of the field party near Sambrito Creek, Sec. 15, T 32 N, R 6 W, 5, 980', San Juan Co . , New Mex. Two specimens were collected from this general area by the University of Utah Ecological Researches party in the summer of 1960 (S.D. Durrant, personal communication). Vegetation at the locality where the animals were seen is largely scattered sagebrush, but excellent grass, willows, narrow-leaf cottonwoods and a few junipers are nearby and irrigated croplands lie on Miller Mesa immediately above the site. Although the presence within the study area of an animal usually considered to be a hig h mountain form in southern Colorado and northern New Mexico was unexpected, a possible explanation lies in the nearby irrigated green crops, which provide an avenue to the higher country to the north via the Piedra Valley, with relatively few stretches entirely free of green fodder. Presence at such an altitude under these conditions shows likelihood of marmots being limited in their southern distribution not by climatic conditions acting directly upon the animals themselves, but because of the absence of suitable green foods. Slight increases in moisture over present conditions might very well lead to a considerable expansion of range. Localities: COLORADO: La Plata C o . : F l o r i d a , 7200' (Howell, 1915, p.55). Archuleta C o . : Gordon Creek near jct . with Piedra River (1).

34

•


Citellus leucurus ( M e r r i a m ) Wh ite -ta iled An telop e Squirrel

Th is sma ll g round squirrel enters th e Blan co Lan d Form , wh ere it is found on th e cany on bottom s among sagebrush, greasewood, and other canyon floor shrubs. V eg eta tion on the canyon walls and mesa top s is of th e p iny on- jun iper unit. The squirrel was not found in the Junction Land Form , but a pproa ch es th e southern edges an d m ay en ter in yea rs of h igh population n umb ers. S outh and west of the Blanco Land Form the animal is ubiquitous except in the m ore d evelop ed riparian habitats. It is p erhap s more comm on ab out washes and rocky outcrops, b ut a lso occurs in flat a reas. In th e la tter p laces, bannertail ka nga roo ra t d en s may b e occupied, al th ough p rob ab ly any burrow system of suitab le size may b e utilized . Loca lities: NEW MEXICO: San Juan C o . : 1 /2 m i. S of Archuleta (1); Aztec (Ba iley, 193 1, p .95 ); b etween Aztec and Lap la ta (Howell, 1938 , p. 17 6 ); Sec. 29, T 30 N, R 8 W, 5800 ' (1 ); Fruitla nd (Bailey, 1931, p.95); Blanco Canyon (Bailey, 1931, p.95); Ga le Wa sh , 4 mi. E and 2 mi. S of Bloomfield (2 ); ab out 3 mi. E and 3 mi. S of Farm ing ton (4 ); about 3 mi. E and 3 m i. S of Blan co, S ec. 34 , T 29 N, R 9 W, 58 00' (1 ); 5 m i. N and 1 /2 mi. W of Waterflow (1 ); 2 1 /4 m i. N and 1 1/4 mi. E of Wa terflow, S ec. 2 8, T 30 N, R 15 W (1); 7 m i. S and 6 m i. W of Bloomfield, Sec. 4, T 27 N, R 12 W (1 ); 11 m i. E and 13 mi. S of Fa rm ing ton (1 ).

•

the dens of the bannertail kangaroo rat upon occasion. Localities: NEW MEXICO: San Juan Co.: 7 mi. S and 6 mi. W of Bloomfield, Sec. 4, T 27 N, R 12 W (1); 14 mi. S and 2 mi. W of Farmington (1); 1 1 m i . E and 13 mi. S of Farmington (2).

•

Citellus variegatus (Erxleben) Rock Squirrel

The rock squirrel is widespread and common in pinyon- juniper areas in much of the Blanco Land Form and its range continues north well into the ponderosa pine Douglas fir unit. It is most common in rocky areas but has been found in well developed riparian growth and about cultivated cropland near farm buildings. This ground squirrel was neither seen nor collected south of the San Juan R i v e r , even in areas very similar to its habitat north of the r i v e r . Warren (1942, p. 118) states: "In Colorado it is found from 8, 000 feet down." Localities: COLORADO: La Plata C o . : Allison (1). Archuleta C o . : Deep Canyon, 4 mi. S and 1/2 mi. W of Chimney Rock (1); near mouth Deep Canyon (1). NEW MEXICO: San Juan Co.: extreme SW corner Sec. 14, T 32 N, R 6 W (1); Pine River Canyon, Sec. 20, T 31 N, R 7 W (3); Pine River, NE 1/4 Sec. 7, T 30 N, R 7 W (1); Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W (1); Pine River, NW 1/4 Sec. 8, T 30 N, R 7 W (2); jct. San Juan and Pine Rivers (1).

Citellus spilosma (Bennett) Sp otted Ground Sq uirrel

Th is sp ecies was found only in rela tively fla t gra sslan ds south of the San Juan River, where it occurs sym patrically with the wh ite -ta iled a n telop e sq uirrel. Grasses, Morm on tea, tumb leweed , a nd yuccas are common m emb ers of the veg etation. This an ima l, like th e an telop e sq uirrel, utilizes

•

Citellus lateralis (Say) Goldenmantled Ground Squirrel

This ground squirrel was not found in the main study area but a specimen was taken a short distance to the east, and others

35

ACCOUNTS OF SPECIES

in the m ead ows an d edg e of t h e sp ruce forest on th e up per P iedra R i v e r . A rela tively slight in crea se in moisture would p robab ly allow inva sion of th e more m esic p ortion s of the stud y a rea . Loca lities: COLORADO: Arch uleta C o . : Gordon Creek n ear jct. with P ied ra River (6 ); P ag osa Sp ri ng s (Howell, 1938 , p. 194). NEW MEXI CO: Rio Arriba C o . : ab out 5 mi. W and 4 m i. N of Dulce (1 ).

•

Cy nom ys g unn ison i (Ba ird ) Gunn ison' s P r a i r i e Dog

Because of poisoning campaigns, the present d istrib ution of th e pra irie d og is a question ab le reflection of t h e pa st d istrib ution, an d may b e somewha t restricted compared to ea rlier day s. Th e n orthernm ost colon ies loca ted in Colorado were n ea r Allison, n ea r S am b rito Creek close to th e sta te lin e, an d on Miller Mesa. In New Mexico, th ere wa s a colony near Rosa. Th ese town s were on or n ea r cultivated or recen tly cultiva ted land . Sagebrush a nd/or pinyon -jun ip er is the common vegeta tional typ e in nearb y un cul tivated a reas. No p ra irie dog town s are known from th e un irriga ted p la tea u top within th e Jun ction Land For m . South of this land form, towns were quite common in the gra ssland s. Non e was found in sag eb rush . Loca lities: COLORADO: Arch uleta C o . : NW 1/4 S ec. 23, T 32 N, R 6 W (1 ); S E 1/4 Sec. 24, T 32 N, R W (1 ). NEW MEXICO: Sa n Juan Co.: NE 1 /4 S ec. 12 , T 32 N, R 7 W;(4 ) S ec. 28 , T 28 N, R 13 W (1); Lapla ta (Ba iley, 1931 , pp . 130 -131 ); N side of va lley a t Fruitland (Ba iley, 19 31, p . 129); Lib erty ( H o l l i s t e r , 1916 , p. 34 ).

sparsely, in the ponderosa pine forests of the higher elevations. L o c a litie s : COLORADO: La Plata C o . : Florida (Warren, 1942, p. 152). Archuleta C o . : Pagosa Springs (Warren, 1942, p. 152).

•

In the northern portions of the study area, pocket gophers appear limited to the bottomlands and, occasionally, to the terraces of the San Juan River and its tribu taries and to the cultivated lands in the vicinity of the state l ine. Vegetation varies from ponderosa pine-Douglas fir forest through domesticated crops such as alfalfa and hay to river bottomland vegetation ( w e l l developed and otherwise). South of the San Juan River, the gopher is distributed in a spotty fashion throu gh the grasslands. There is some concentration along major dry washes where vegetation is somewhat thicker than average, but sizeable areas of occupancy occur elsewhere. L o c a litie s : COLORADO: La Plata C o . : Bayfield (Warren, 1942, p. 160); Los Pinos (Baile y, 1915, p. 75). Archuleta C o . : mouth of Archuleta Canyon (1); near mouth of Deep Canyon (1); Arboles (Warren, 1942, p. 160); NE 1/4 of SE 1/4 Sec. 18, T 32 N, R 4 W (1). NEW MEXICO: San Juan Co.: Pine R i v e r , NE 1/4 Sec. 7, T 30 N, R 7 W (1); jct. Pine and San Juan Rivers (1); Fruitland (Bailey, 1915, p. 75); about 3 mi. E and 3 mi. S of Farmington (1); 7 mi. S and 6 mi. W of Bloomfield, Sec. 4, T 27 N, R 12 W (2).

• •

S ciurus aberti Woodh ouse Abert' s Sq uirrel

Sciurus aberti was not found in the study area , but p robab ly occurs, a t lea st

Thomomys bottae (Eydoux and Gervais ) Southern Pocket Gopher

Thomomys talpoides (Richardson) Northern Pocket Gopher

The northern pocket gopher replaces the southern at higher altitudes. The south-

36


ern p ock et gop her apparen tly is th e only one found within the study area, but probably g oes little furth er n orth b efore it is replaced by th e n orthern species. L o c a l i t i e s : COLORADO: La P lata C o . : Florida, 72 00° (Wa rren , 1942 , p . 1 63 ). Arch uleta C o . : Gord on Creek n ea r jct. with P ied ra River (3 ); Pa gosa P eak (Ba iley , 1915, p .112 ); Pag osa Sp ring s (Ba iley, 191 5, p. 11 2 ).

•

Perognathus flavus Baird S ilky Pock et Mouse

Although primarily an animal of the op en gra ssland s, the silk y p ock et mouse en ters extremely spa rse p iny on- jun iper in th e vicin ity of Blan co. It wa s not found farth er n orth. Localities: NEW MEXICO: San Juan Co.: Fruitland (Goldman , 193 2a, p. 90); 2 m i. NW of Bla nco (4 ); 3 m i. E and 3 mi. S of Fa rm ing ton (2 ); 7 m i. S and 6 m i. W of Bloomfield, S ec. 4 , T 27 N, R 12 W (2).

•

Perognathus apache Merriam Apa ch e P ock et Mouse

Within the Junction Land Form, the Apa ch e p ock et mouse occurs in well devel oped pinyon -juniper stands on the relatively fla t in terfluves ( F i g . 8 ) and a long canyon b ottom la nds am id sag eb rush , g rea sewood, etc. I t seem s to b e q uite ra re in a ll these reg ions, however. To th e south a nd west, it inh abits th e g rassla nds, b oth a long and b etween w a sh es. Here it wa s taken , n ot in frequently, by n igh t hun ting . Localities: NEW MEXICO: San Juan Co.: P in e River R d . , S E 1 /4 of SW 1 /4 Sec. 9 , T 31 N, R 7 W (1 ); Lucero p lace, S E 1/4 of NE 1/4 S ec. 17 , T 31 N, R 7 W (1 ); 5 1/2 m i. N and 1/2 m i. W of Wa ter-

F i g . 8. Perognathus apache habitat in pinyon-juniper growth.

flow, Sec. 12, T 30 N, R 16 W (1); about 3 mi. E and 3 mi. S of Farmington (1); Gallegos Canyon, Sec. 9, T 28 N, R 12 W (1); about 3 mi. E and 3 mi. S of Blanco, Sec. 34, T 29 N, R 9 W, 5800 ' (1); 7 mi. S and 6 mi. W of Bloomfield, Sec. 4, T 27 N, R 12 W (2); 16 mi. S and 1 mi. W of Farm ington, Sec. 17, T 26 N, R 13 W (2). •

Perognathus Wied -Neuwied Pocket Mice

Within the study area, the Apache pocket mouse's range continues north for a c onsiderable distance beyond that of the silky. Within the area of sympatry, however, no dif ferences in habitat were noticed. Members of both species were captured by hand within ten minutes and a hundred yards or less of each other in seemingly uniform ha bitat.

ACCOUNTS OF SPECIES

•

Dipodomys ordi Woodhouse Ord's Kanga roo Ra t

37

•

Castor canadensis Kuhl Beaver

Ord's ka nga roo ra t occurs n orth to the edg e of the Junction Land Form , but not into th a t reg ion excep t, p ossib ly , for sh ort dista nces up th e ma jor river va lley s. I t was common n owh ere with in th e study a rea during th e summ er of 1960 .

At present the beaver occurs along the permanent water-courses within the study area and there is no reason to believe the situation was essentially different in the past, except that irrigation ditches are now utilized in addition to streams.

Th e an im a l app ears limited to the gra ssland s and th ose sta nds of sag eb rush wh ich in clud e many a ssocia tes, such as saltbush and grea sewood . In th e la tter ty pe of habitat, the animals are concentrated mainly along wa sh es.

In most of the area under consider ation, dams are not constructed, the animals constructing burrows. In some places, trees are not present along or near the banks of the inhabited section of r i v e r . Sagebrush, greasewood, and a few willows appear to be the only possible food in such cases.

Th e n orth ern most sta tion for this ani ma l, two m iles NW of Bla nco, is b ased upon a sigh t record. Loca lities: NEW MEXI CO: Sa n Juan Co.: Bla nco (S etzer, 1 949 , p.558 ); Fruitla nd (S etzer, 1949 , p.558 ); Ga le Wa sh , 4 m i. E and 2 m i. S of Bloom field (4); Ga lleg os Can-yon, Sec. 9 , T 2 8 N, R 12 W (2 ); 7 m i. S an d 6 mi. W of Bloom field , S ec. 4, T 2 7 N, R 12 W (1).

•

Dip od omy s sp ectab ilis Merriam Ba nnerta il Kan garoo Ra t

Th e lim its of d istribution of this rodent within the study area are approximately th e sam e a s for Ord' s ka nga roo ra t, and the bannertail is found in much the same type of vegeta tion. Loca lities: NEW MEXI CO: Sa n Juan Co.: nea r Fruitland (Ba iley, 19 31, p .260 ); near Bloomfield, N side of San Juan River (Bailey, 19 31, p .260 ); Bla nco Can yon (Ba iley, 1931, p.260 ); Largo Can yon (Ba iley , 193 1, p .260); 7 m i. S and 6 m i. W of Bloomfield , S ec. 4, T 27 N, R 12 W (1 ); 1 m i. E an d 9 m i. S of Bloomfield, S ec. 11 , T 27 N, R 11 W (1 ); Ga lleg os S tore, 10 m i. S and 7 m i. W of Bloomfield (1 ).

Localities: NEW MEXICO: San Juan Co.: jct. of San Juan and Pine R i v e r s , NW 1/4 Sec. 17, T 30 N, R 7 W (1).

• Reithrodontomys megalotis (Baird) Western Harvest Mouse The western harvest mouse ranges widely through the study area in croplands, sloughs, marshes, and wash edges. In cultivated areas, the animal is common in alfalfa, hay, and weeds; away from areas of cultivation, its habitat is in the growth of grasses and bushes along the courses of washes. Such situations often are relatively barren, with individual plants widely spaced (though less so than away from the washes). In the Pine River Canyon, one specimen was collected from among rocks of the canyon wall, some twenty to thirty feet above the upper r i v e r t e r r a c e . Vegetation here is of scattered pinyons and junipers with their associated shrubs and forbs. This is the only case where a harvest mouse was taken among such surroundings. The species probably extends well to the north of the study area in the river valleys.


38

L o c a l i t i e s : COLORADO: La Plata C o . : Allison (4 ). Arch uleta C o . : 6 mi. S and 4 1/2 mi. W of Chimney Rock (2); NE 1/4 of S E 1/4 S ec. 18 , T 32 N, R 4 W (6 ); NW 1/4 S ec. 23 , T 32 N, R 6 W (1 ); 1 m i. E and 0.2 m i. N of Arb oles (1 ); Arb oles (Wa rren, 19 42, p .196 ). NEW MEXI CO: Sa n Juan Co.: Lap la ta (Howell, 1914, p.30); Aztec (Howell, 1914 , p.30 ); extreme NW 1/4 of NW 1/4 S ec. 9 , T 32 N, R 6 W (1); Ulibarri Ca nyon, N 1 /2 Sec. 2 5, T 32 N R 7 W (1); P ine River Cany on , S ec. 2 0, T 31 N, R 7 W (7 ); P in e River, NW 1 /4 S ec. 7, T 30 N, R 7 W (5 ); P in e River, NE 1 /4 S ec. 7 , T 30 N, R 7 W (2 ); P in e River, S W 1/4 S ec. 8, T 30 N, R 7 W (3 ); ab out 3 m i. N (by road ) of Archuleta (2); Fruitland (Howell, 1914, p .3 0 ); 1 1/2 mi. W of Fa rm ing ton (1 ); Farm ing ton (Howell, 1914, p .30 ); 1 112 m i. W of Bloomfield (1); Bloomfield (1 ); Ga lleg os Cany on , Sec. 9, T 28 N, R 12 W (4 ); 16 m i. S and 1 m i. W of Fa rm ing ton , Sec. 17, T 26 N, R 13 W (2).

•

P erom yscus crin itus ( M e r r i a m ) Ca nyon Mouse

In th e a rea und er consideration, P erom yscus crin itus ap pea rs to reach th e north ern lim its of its rang e at about th e New Mexico -Colorad o sta te line. Wa rren (194 2, p .204 ) sta tes that "...it ap pea rs to live exclusively am ong rocks, ... " Th e p resen t author find s no reason for d isag reemen t h ere, and, in fa ct, it seems that th e p resence of rock s alon e is n ot always sufficien t and tha t somewha t jumbled blocks a re usua lly presen t. Thus, th e mouse most often is found wh ere deb ris from a cliff face ha s a ccum ula ted a t th e ba se. As y et, these m ice ha ve n ot been ta ken with in th e study a rea in other than pinyon- juniper vegetation, though this unit ha s n ot a lway s been well d evelop ed. Loca li ties: NEW MEXICO: San Juan Co.: P in e River, NW 1 /4 S ec. 7 , T 30 N,

R 7 W (2); 5 1/2 mi. N and 1 1/2 mi. W of Waterflow, Sec. 12, T 30 N, R 16 W (3); about 3 mi. E and 3 mi. S of Farmington (3); about 3 mi. E and 3 mi. S of Blanco, Sec. 34, T 29 N, R 9 W, 5800' (5).

• Peromyscus maniculatus (Wagner) Deer Mouse The deer mouse is extremely wide spread throughout the study area. Nearly any line of traps of reasonable number produced at least one specimen, almost regardless of habitat. Highest population numbers appear to have been in the spruce and ponderosa pine- Douglas fir forests of the upper Piedra R i v e r , in areas of contemporary or recent cultivation, and, at least during the summer of 1960, in the almost pure sage-brush flats of the Junction Land F o r m . Even in conditions seemingly optimal for other species of Pe romyscus, a few speci mens of this species were almost invariably taken. The deer mouse was rarest in open, unbroken grassland and was not taken in several stations located in this vegetational unit. Here, other species of the genus were also absent. Localities: COLORADO: La Plata C o . : Durango (Warren, 1942, p. 200); Bayfield (Warren, 1942, p. 200); Allison (6). Archuleta C o . : Pagosa Springs (Warren, 1942, p. 200); Gordon Creek near jct. with Piedra River (11); 0.4 mi. S ( by road) of the jct. of Colo. 151 and US 160 (2); mouth of Archuleta Canyon (5); Archuleta Canyon (5); Stollsteimer Creek near mouth of Deep Canyon (6); Deep Canyon, 4 mi. S and 1/2 mi. W of Chimney Rock (18); 6 mi. S and 4 1/2 mi. W of Chimney Rock (1); 6 1/2 mi. S and 5 mi. W of Chimne y Rock (2); 1 1/4 mi. E and 1 mi. S of Chimney Rock (5); Piedra River, NW 1/4 Sec. 4, T 32 N, R 5 W (10) ; Arboles (Warren, 1942, p. 202); 1 mi. E and 0.2 mi. N of Arboles (3); Carracas -Arboles R d . , NE 1/4 of SW 1/4

ACCOUNTS OF SPECIES

Sec. 1 7 , T 32 N, R 4 W ( 8 ) ; Sandoval Can-y on , S E 1 / 4 o f S E 1/4 S e c. 12, T 32 N, R 5 W (2 ); NE 1/4 of S E 1/4 S ec. 18, T 32N, R 4 W ( 9 ) ; 2 mi. W and 1 mi. N of Juanita ( 9 ); NW 1/4 S e c. 2 3 , T 3 2 N , R 6 W (3 ); E s i d e of S a n J ua n R iv er, NW 1/4 S e c. 21, T 3 2 N, R 5 W (5 ) . N EW M EXI CO : Sa n Juan Co.: Laplata (J. A . A l len , 1 8 9 3 , p . 74); A z t ec ( J . A . A l l e n , 1 8 9 3 , p.74); 5 1 /2 m i. N a n d 1 1 /2 m i. W of W a te rf lo w , S ec . 12 , T 3 0 N, R 1 6 W (2 ); 2 1/4 m i. N a n d 1 1 / 4 m i. E o f Wa te rf l o w, S e c. 2 8 , T 3 0 N, R 15 W ( 3 ); 2 1 /2 m i . W a n d 1 / 2 m i. S of R os a, NE 1 /4 S ec . 1 6 , T 3 2 N , R 6 W (1 3 ) ; Sambrito Creek , S W 1 /4 of S E 1/4 Sec. 15, T 32 N, R 6 W (2 ) ; P in e R iv er Ca n y on , Sec. 20, T 31 N, R 7 W ( 1 0 ) ; Lucero place, S E 1/4 o f N E 1 /4 S ec . 17, T 3 1 N, R 7 W ( 6 ); P in e R i ve r, NW 1 /4 S e c. 7 , T 30 N, R 7 W (6 ); P in e R i ve r, NE 1 / 4 S ec . 7 , T 30 N, R 7 W (3 ) ; P in e R iv er R d . , S E 1 /4 of SW 1/4 S ec . 9 , T 3 1 N, R 7 W (2 ); e x t r em e NW 1/4 o f N W 1 /4 S e c. 9 , T 3 2 N , R 6 W ( 1 ) ; N W 1 /4 S ec . 1 1 , T 3 2 N , R 6 W ( 2 ); E 1 / 2 of N W 1 /4 S e c. 1 0 , T 3 2 N, R 6 W (2 ) ; N W 1 /4 of S W 1 /4 S ec . 4 , T 30 N, R 7 W (2 ); S W 1 /4 of NE 1/4 S ec. 24, T 32 N, R 7 W (1 ) ; 9 m i . S a n d 6 1 /2 m i. W o f B l o om f i e ld (5 ) ; 9 m i. S o f B l oom f ie ld , S ec . 1 0 , T 2 7 N, R 1 1 W (2 ) ; 3 1 /2 m i. E and 7 m i. S of B lo om f i e ld , S ec . 3 2 , T 2 8 N, R 1 0 W (2 ); U lib a rri Ca n y on , N 1 /2 S ec. 25, T 3 2 N, R 7 W (2 4 ) ; 2 m i. NW o f B lan co ( 3 ); Ga l l eg o s Ca n y on , S e c. 9 , T 2 8 N, R 12 W (3); a bout 3 mi. E a nd 3 mi. S of F a rm in g t on (4 ); S ec . 2 9 , T 3 0 N , R 8 W , 5 8 0 0 ' (2 ); Ga l e W a sh , 4 m i . E a n d 2 mi. S of B lo om f i e ld (2 ) ; a b o u t 3 m i. E and 3 m i. S of Blan co, S ec. 34 , T 29 N, R 9 W, 5800' ( 5 ); 1 6 m i . S a n d 1 m i. W of Fa rm ing to n, S ec . 1 7 , T 2 6 N, R 1 3 W (5 ). R i o Ar r iba C o .. : S W 1 /4 S e c. 2 3 , T 3 2 N, R 6 W (2 ); e x t rem e S E co rn e r S ec . 2 2 , T 3 2 N , R 6 W ( 1 ).

•

P er om y s cu s b oy l i i ( Ba ir d) B r u sh Mo us e

Th e b rush m ouse is p red ominately a r ock d we l le r of th e p in y on -j un ip e r un it,

39

b u t in v ery we ll d ev e lop ed p iny on- j un ipe r with in th e J unc tion Land F orm , th e m ou se may be taken fa r fr om any ma jo r ro ck ou tc r ops , in qu ite lev e l a re as . In se v era l ca se s, th e b ru sh m ou se was fo und whe re pinyon was absent and junipers very sparse, in h eavy tr ee and shr ub gr o wth of r ipa r ian c hara c te r. The c rea ture e n te rs the lo we r pa r ts o f th e p onde ro sa p in e- Do ug las f ir forest. L o c a litie s : CO L OR AD O: A rch u le ta Co.: 6 1/2 m i. S and 5 m i. W o f C h im n ey Ro ck (1 ); P iedra R i v e r , NW 1 /4 Se c.4, T 32 N, R 5 W (2 ); Sand ova l Canyon , S E 1 /4 of SE 1/4 Se c. 12, T 32 N, R 5 W (1 ); 2 m i. W and 1 m i. N of Ju an ita (20 ); 1 m i. E and 0.2 m i. N o f Arb o les (2 ). NE W M E XI CO: San J uan Co.: La plata (O sgo od, 1909 , p .147); A z te c (Os go od, 1909,p .147 ); S ec . 29 , T 30 N, R 8 W, 5800' (3 ); 5 1 /2 m i. N and 1 1 /2 m i. W o f Wa te rf lo w, Se c. 12 , T 30 N, R 16 W (6 ); 2 m i. NW o f Blan co (1 ); P ine R ive r Cany on, Se c. 20, T 31 N, R 7 W (13); NW 1/4 of SW 1/4 Sec. 4, T 30 N, R 7 W (7 ); Lu c e r o P la ce, S E 1 /4 of NE 1/4 S ec . 17 , T 31 N, R 7 W (1 ); jc t. San Juan and P ine R i v e r s , NW 1/ 4 Sec. 17, T 30 N, R 7 W (5); Benito Canyon, NE 1/4 of NW 1/4 Sec. 29, T 32 N, R 7 W ( 9 ) ; Sambrito Creek, SW 1/4 of SE 1/4 Sec. 15 , T 32 N, R 6 W (5 ); P ine Riv er Rd ., S E 1 /4 of S W 1 /4 S ec . 9 , T 31 N, R 7 W ( 2 ) ; Pine River, NW 1/4 Sec. 7 , T 30 N, R 7 W (21).

•

Peromyscus truei (Schufeldt) P iny on Mo us e

L ike the br ush mo us e, th e p iny on m ou se is mo s t con cen tr a ted in th e p iny onju n ipe r un it. Ho wev er , s om e ind ividua ls o c cu r in c u ltiva ted land s and abo u t farm b u ild ings , in r ipar ia n gr o wth, and in th e sagebrush wash types of habitat. In the latte r two cas es , p iny on -ju n ipe r us ua lly is p re sen t within a fe w hu ndr ed ya rds , a l th ough o f ten on ly spa rs e ly s o. In spa r se, v e ry open p inyon -jun ipe r with f e w or no


40

rock outcropp ing s, the an ima l may occur in fa irly la rge n umb ers. Rarely, the pinyon mouse may be found at considerable distances from any p inyon- jun iper. North of Wa terflow, it was trapped among Sarcobatus and Artemisia g rowing on fla ts b ord ering en trench ed a rroy os, on rocky h illsides, and on sa nd dun es. Th e n ea rest p inyons or jun ip ers a re severa l m iles d ista n t. Loca lities: COLORADO: Archuleta C o . : P iedra R i v e r , NW 1 /4 S ec. 4, T 32 N, R 5 W (1 ). NEW MEXI CO: Sa n Juan C o . : Lap la ta (Osg ood, 190 9, p. 1 69 ); Aztec (Hoffm eister, 1 951 , p . 39 ); P in e River Rd., N 1 /2 of S W 1 /4 S ec. 25 , T 32 N, R 7 W (1); S W 1/4 of NE 1 /4 Sec. 24 , T 32 N, R 7 W (1 ); P in e River R d . , S E 1 /4 of S W 1 /4 Sec. 9 , T 31 N., R 7 W (9 ); Lucero p lace, SE 1/4 of NE 1/4 S ec. 17 , T 31 N, R 7 W (1 ); E 1 /2 of NW 1 /4 S ec. 10, T 32 N, R 6 W (1 ); NW 1 /4 S ec. 11, T 32 N, R 6 W (1); jct. Pine and San Juan R i v e r s , NW 1/4 S ec. 1 7, T 30 N, R 7 W (1 ); NW 1 /4 of SW 1 /4 S ec. 4 , T 30 N, R 7 W (4 ); P ine River, NW 1/4 S ec. 7 , T 30 N, R 7 W (2 4 ); Pine River, NE 1 /4 Sec. 7 , T 30 N, R 7 W (1); P ine River Cany on , S ec. 2 0, T 31 N, R 7 W (2 ); S ec. 2 9, T 30 N, R 8 W,5800' (3); 5 1 /2 m i. N an d 1 1 /2 m i. W of Wa terflow, S ec. 12 , T 30 N, R 1 6 W (11 ); 1 1 /2 mi. N an d 1 1 /2 m i. E of Wa terflow (2 ); 2 1/2 mi. N and 1 1 /4 m i. E of Wa terflow, Sec. 28, T 30 N, R 15 W (4 ); n ea r Fruit- la nd (Bailey, 19 31, p . 153 ); 2 m i. NW of Blan co (4); Bla nco (Hoffmeister, 1951 , p . 3 9 ); about 3 m i. E an d 3 m i. S of Blan co, S ec. 34, T 29 N, R 9 W, 580 W (1 ); 9 m i. S of Bloomfield , S ec. 10 , T 27 N, R 11 W (5); 1 m i. E and 9 m i. S of Bloomfield, Sec. 11, T 27 N, R 11 W (1 ); 3 1 /2 m i. E and 7 mi. S of Bloomfield, S ec. 32 , T 28 N, R 10 W (4). Rio Arrib a C o . : S W 1 /4 Sec. 2 3, T 32 N , R 5 W (1 ).

•

P erom yscus Gloger Wh ite- footed Mice

Four sp ecies (P eromy scus crinitus, P . man icula tus, P . truei, an d P. b oylii),

of this genus occur in the study area. In some localities, all four may be taken in close proximity to one another. None, however, has the same distribution as any other. Peromyscus crinitus has the most restricted habitat requirements and the most restricted range within the area. Specimens were taken exclusively among rocks within the pinyon -juniper zone. In contrast, P . maniculatus spans the entire study area, occurring from spruce forest at the northern checkpoint south through all vegetational units into grasslands south of the San Juan. It at tains greatest numbers where competition from other species is of low level (as in cultivated fields, spruce and ponderosa pine - Douglas fir f o r e s t s , and in sagebrush), but does occur with all the other species. Peromyscus truei and P . boylii overlap broadly in their ranges, but the former is somewhat more tolerant of xeric and open are as than is P . boylii; the latter is more tolerant of the habitats found at higher altitudes. Thus, P . boylii is absent in the south from areas occupied by P. truei; the reverse is true in the north. With- in the areas of sympatry, P . truei tends to be more common on rather open slopes and in croplands and riparian growth than is P. boylii; the latter tends to be commonest in the more rocky areas or in areas of heavy nonriparian plant c o v e r . The habitats of the two kinds are not mutually exclusive, however.

• Onychomys leucogaster (Wied- Neuwied) Northern Grasshopper Mouse The northern grasshopper mouse was rarely taken within the study area. A crew of the University of Utah Ecological Researches captured several specimens in the vicinity of Rosa, Rio Arriba C o . , N. Mex. (S.D.Durrant, personal communica tion). A l l other specimens are from south of the Junction Land Form.

41

ACCOUNTS OF SPECIES

Sp ecim en s collected d uring th e course of th is study were ta ken from an a rea of sag eb rush with g ra ssland n earby, from g ra ssland , a nd from spa rse p inyon jun ip er growth .

field (1); 11 mi. E and 13 mi. S of Farmington (1).

• Loca lities: NEW MEXI CO: Sa n Juan Co.: Lap la ta ( H o l l i s t e r , 1914 , p .446 ); near Fruitland (Ba iley , 1931, p . 138 ); 2 m i.NW of Bla nco (1 ); Ga lleg os Cany on , Sec. 9, T 28 N, R 12 W (1 ); 11 m i. E a n d 1 3 m i . S of Fa rm ing ton (3 ); 7 m i. S and 6 m i. W of Bloomfield, S ec. 4 , T 27 N, R 12 W (1 ). Rio Arrib a C o . : r i v e r m ile 16 5 from jct. San Juan and Colorado Rivers (S. D. Durrant, in l i t t . ) ; r i v e r m ile 1 65 .5 (S . D. Durrant, in l i f t . ) ; r i v e r m ile 166 (S .D. Durran t, in l i tt . ) .

•

Neotoma albigula Hartley Wh ite -th roa ted Wood Ra t

Th is wood ra t is widespread, occurring from riparian va lley s with in th e lower levels of th e p on derosa p ine- Doug la s fir zone south to the edges of grassland washes south of th e San Jua n. I t wa s n ot tak en in sag eb rush . Rocky a reas a re fa vored wh en availab le; wh ere rocks a re ab sen t, b urrows a- long th e edges of a rroy os a re utilized . In addition, on e n est, p robab ly constructed by th is sp ecies, wa s found b uilt ab out the ba se of a wild olive t r e e . Loca lities: COLORADO: La P la ta C o . : Man cos -San Juan River reg ion in Mon tezuma and La P la ta Coun ties (Warren, 19 42, p . 212 ); near Bond ad (Wa rren, 1942, p . 212 ). Archuleta C o . : S tollsteimer Creek n ea r mouth of Deep Cany on (1 ); S E 1 /4 of NW 1/4 S ec. 18 , T 32 N, R 4 W (1 ); 2 mi. W an d 1 m i. N of Juan ita (1 ). NEW MEXICO: Sa n Juan Co.: P in e River Rd . N 1 /2 of SW 1 /4 S ec. 25 , T 32 N, R 7 W (1 ); P in e River, S ec. 6 , T 3 0 N, R 7 W (1 ); ab out 3 m i. E and 3 m i. S of Farm in g ton (1 ); Ga llegos Canyon, S ec. 9 , T 2 8 N, R 12 W (1 ); 9 m i. S an d 6 1 /2 m i. W of Bloom-

Neotoma stephensi Goldman Stephens' Wood Rat

In the Junction Land Form, N. stephensi occupies cliffs and rock outcrops of the pinyon -juniper zone. To the south, i t may occur away from rocky areas in well developed, but not necessarily dense, pinyon- juniper stands. In the latter areas, dens are built about the bases or low -slung branches of junipers or in vertical crevices in the al luvium or clay of arroyo banks. When built about junipers, burrows, of a size suggesting they may belong to this species, are often present near the nest. On two occasions, arboreal nests were found in junipers. One such nest had its base approximately five feet above the surface of the ground on an almost horizontal limb, some 2 1/2 - 3 feet from the trunk; the nest was about 1 1/2 feet in height and in horizontal diameter. The other arboreal nest was some six feet above ground and several feet from the main trunk, but was little more than a covered platform, less than a foot in height. Nests are constructed mainly of juniper twigs, many of which retain green f o l i a g e . Chunks of manure, bones, and cactus joints may or may not be present. Localities: NEW MEXICO: San Juan Co.: Pine River R d. , N 1/2 of SW 1/4 Sec. 25, T 32 N, R 7 W (1); jct. San Juan and Pine Rivers, NW 1/4 Sec. 17, T 30 N, R 7 W (1); Sec. 29, T 30 N, R 8 W, 5800' (1); about 3 mi. E and 3 mi. S of Farming -ton (1); Blanco (Goldman, 1932b, p.67); a -bout 3 mi. E and 3 mi. S of B lanco, Sec. 34, T 29 N, R 9 W, 5800' (1); 9 mi. S of Bloomfield, Sec. 10, T 27 N, R 11 W (3); 1 mi. E and 9 mi. S of Bloomfield, Sec. 11, T 27 N, R 11 W (1).

42

•


Neotoma mexicana Ba ird Mexican Wood Ra t

Thus, there appears to be a hiatus, within which lies the study area, between the geographic ranges of the two subspecies.

Th e Mexican wood ra t is a rock d weller in the p ond erosa p in e-Douglas fir an d p iny on- jun iper zones, extending in p laces to th e very south ern edg e of the latt e r , wh ere on ly sca ttered jun ip ers occur. A sp ecimen is ava ilab le also from a relict con ifer area .

Localit ies: COLORADO: Archuleta C o . : near jct. Gordon Creek and Piedra River (2). NEW MEXICO: San Juan Co.: 18 mi. N and 1 mi. E of Farmington (Finley, 1958, p. 270); Fruitland (Goldman, 1910, p. 106); Farmington (Bailey, 1931, p. 191).

Loca li ties: COLORADO: Archuleta C o . : S tollsteim er Creek n ear m outh of Deep Can yon (1 ); Deep Ca nyon, 4 mi. S an d 1 /2 m i. W of Ch imn ey Rock (3); Piedra R i v e r , NW 1 /4 S ec. 4 , T 32 N, R 5 W (1); NE 1 /4 of S E 1 /4 S ec. 18 , T 32 N, R 4 W (1). NEW MEXI CO: _______ Sa n Juan Co.: Benito Ca nyon, NE 1/4 of NW 1 /4 S ec. 29, T 32 N, R 7 W (1 ); NW 1 /4 of SW 1/4 S ec. 4, T30 N, R 7 W (1 ); jct. San Juan and P ine R i v e r s , NW 1 /4 S ec. 17 , T 30 N, R 7 W (1 ); P ine River, NW 1/4 S ec. 7 , T 30 N, R 7 W (6 ); 18 mi. N an d 1 m i. E of Fa rm ington (Fin ley, 1958, p. 28 8 ); Lap la ta (J. A. Allen , 1893 , p. 81); 5 1/2 m i. N and 1 1/2 m i. W of Wa terflow, Sec. 12, T 30 N, R 16 W (1 ); Fruitla nd (Goldman, 19 33, p . 472 ); near P ine R i v e r , S ec. 20, T 31 N, R 7 W (4 ).

•

 

Neotoma cin erea (Ord ) Bushy-tailed Wood Rat

Ba iley (1 931 , p.1 91 ) rep orts the b ushy-ta iled wood ra t from Fa rm ington; from Sh iprock , west of th e study a rea; and from Ch aco Cany on , to th e south. He gives its ha b ita t a s op en d esert- va lley country, usually in sandstone cliffs and ledges in the upp er S on oran l if e -z o n e . In contrast to the above subspecies, N . c . a rizona e, N. c . orolestes d wells in the tran sition and Ca nad ian Life-zon es, in th e m oun ta in ous region s of Colorado and New Mexico. Two sp ecim en s of th is form were collected from th e upp er P iedra River. Con sid erab le trap p ing in p oten tial habitat with in th e Reservoir area fa iled to produce evidence of bushy-ta iled ra ts there.

Neotoma Say and Ord Wood Rats

Neotoma albigula, N. mexica na, N. stephensi, and N. cinerea occur in the study area. One of these, N. cinerea, is represented by two subspecies, N. c. orolestes in the extreme north and N. c. arizonae in the vicinity of Farmington. The major portion of the study area appears to be within a hiatus in the range of N. cinerea. N. c. orolestes is known from the northern checkpoint at Gordon Creek, but not to the south; N. c. arizonae has been reported from Farmington, but not to the northeast. The areas are far different, with spruce and ponderosa pine - Douglas f i r forests in the north, scattered pinyon juniper in the south. Of the other species, all have been taken in the vicinity of the junction of the San Juan and Pine Rivers at seemingly identical si tes insofar as vegetation and physiographic features are concerned. Con sidering the ranges of each within the study area as a whole, N. mexicana extends to higher altitudes than does N. albigula, and N. stephensi is limited approximately to the pinyon- juniper zone.

•

Microtus pennsylvanicus (Ord) Meadow Vole

The meadow vole occurs along the San Juan River south of the Junction Land

ACCOUNTS OF SPECIES

F o r m . Although it seem s not to extend north beyond the neighborhood of Blanco on the San Juan, its range does extend up th e va lley of the An imas River n orth of Aztec. During the period of investigation, no sign of this animal was found except in ma rshy area s tha t supp orted sedges, desp ite n ea rby field s of d en se g ra sses and crops that would seem to provide equally g ood cover. The northward distribution of this sp ecies would seem to b e lim ited by the a va ilab ility of marshy a reas. At present, th ere a re la rg e g aps sepa ra ting any sizeable areas of marshland or sloughs north of Blanco, on the San Juan, and north of Ceda r Hill, on the An ima s. The animal is not k nown from Colorad o west of approxim a tely the con tin en ta l d ivid e Loca lities: NEW MEXI CO: _San Juan C o . : La p la ta (Ba iley, 193 1, p . 203); Aztec (Ba iley, 193 1, p . 203 ); 5 1 /2 m i. N of Aztec on sta te road 550 (1 ); Fruitland (Bailey, 19 31, p . 203 ); Fa rm ington (Ba iley, 1931, p. 20 3 ); 4 m i. W of Bloomfield (1 ); 1 1/2 mi. W of Bloomfield (2 ); Blanco (1 ); Sa n Juan River a t Bla nco (1 ).

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Allison (2). Archuleta C o . : 2 mi. E and 1/2 mi. N of Chimney Rock (7); 1 1/4 mi. E and 1 mi. S of Chimney Rock (4); NE 1/4 of SW 1/4 Sec. 17, T 32 N, R 4 W (1); NE 1/4 Sec. 23, T 32 N, R 6 W (2). NEW MEXICO: San Juan Co.: E 1/2 of NW 1/4 Sec. 10, T 32 N, R 6 W (2); Sambrito Creek, S 1/2 Sec. 15, T 32 N, R 6 W (2).

• Microtus longicaudus ( M e r r i a m ) Long -tailed Vole The long- tailed vole occurs south to the lower border of the ponderosa pine Douglas fir f o r e s t . At the lower limits, it was found in dense r iparian habitat. Elsewhere, it seems to prefer the more open shrubbery along wash edges and de bris within the ponderosa pine- Douglas fir zone. Localities: COLORADO: Archuleta C o . : Deep Canyon, 4 mi. S and 1/2 mi. W of Chimney Rock (24); Stollsteimer Cree k near mouth of Deep Canyon (1); 1 1/4 mi. E and 1 mi. S of Chimney Rock (1); NE 1/4 of SE 1/4 Sec. 18, T 32 N, R 4 W (1).

• •

Microtus montanus ( P e a l e ) Mon tan e Vole

Th e hab ita t of Microtus montanus ex ten ds from th e Canad ian life-zone (Wa rren , 1942 , p. 23 0 ) d own th rough the p ond erosa p in e -Doug las f i r zon e into thick g ra sses, irriga ted crop lan ds, and riparian g rowth with in the p inyon- jun ip er zone. It requires very th ick cover, usua lly in the form of d en s e g ra ss. In m ost of the study a rea, th is m ean s it is lim ited ma inly to strea m b ord ers and marshy area s. South of Sa mbrito Creek , on the San Jua n, such ha b ita t is grea tly restricted or absent. Loca lities: COLORADO: La Plata C o . : Florida (Wa rren, 194 2, p . 230);

Microtus Schrank Meadow Voles

Three species of _ Microtus occur within the study area, M. pennsylvanicus in the south, and M. montan us and M. longicaudus in the north. Microtus pennsylvanicus at present is limited rather strictly to mesic areas of sedges and, perhaps, other thick, low vegetation along watercourses; it seems unable to bypass even relatively short dis tances lacking such habitat. Microtus montanus and M. longicaudus are sympatric over much of their ranges in the study area. In general, M. montanus occurs most often in areas of

44


low, th ick veg eta tion , wh ile M. longicaudus tend s to inh ab it m ore op en a reas. Although M. long ica ud us may inh ab it g enerally more xeric hab ita ts th en M. m on ta nus, it does n ot extend a s fa r south a s the la tter. This well may b e a result of th e rela tionships of vegeta tive covers south of th e range of M. long ica ud us wh ere, th ough d ense cover is a va ilab le in the imm ed ia te vicin ity of strea ms and in irriga ted crop la nds, away from such a rea s th e veg eta tive cover be comes extremely scan ty with little or no tran sition . Th us d en se cover id eal for M. m on ta nus is a va ilab le, b ut surrounding cover is in sufficien t for M. _ long icaudus.

•

Ondatra zibethicus (Linnaeus) Musk ra t

Musk ra ts occur in th e irrigated reg ion s and in ma rshy p la ces n ea r the per ma nen t streams of th e study area. Burrows an d feed ing sta tions were seen in a number of in sta nces. All specim en s are of skulls or carca sses p ick ed up in the f i e l d . S ome may not represen t p laces of live occurrence. For examp le, th e specim en from one mile east an d n ine m iles south of Bloom field was found severa l m iles from th e nearest p erman en t wa ter. Loca lities: COLORADO: La Plata C o . : Allison (1 ). NEW MEXI CO: ________ San Juan Co.: Sam brito Creek , S 1 /2 S ec. 15, T 32 N, R 6 W (1 ); Farm ing ton (Ba iley , 1931,p.207); Bla nco (Ba iley , 1931 , p. 2 08 ); 1 mi. E and 9 m i. S of Bloom field (1 ).

•

Mus musculus Linnaeus House Mouse

House m ice were found in marshy areas along the permanent streams of the study area , m a in ly n ear fa rms, but also in weedy situa tions.

Localities: COLORADO: La Plata C o . : Allison, E 1/2 NW 1/4 Sec. 15, T 32 N, R 6 W ( 8). NEW MEXICO: San Juan Co.: Pine River Canyon, Sec. 20, T 31 N, R 7 W (1); extreme NW 1/4 of NW 1/4 Sec. 9, T 32 N, R 6 W (1); Pine River, SW 1/4 Sec. 8, T 30 N, R 7 W (1); 1 1/2 mi. W of Bloomfield (1); Bloomfield (1); Blanco (1).

•

Zapus princeps J . A . A l l e n Western Jumping Mouse

A single specimen was taken in a dense mixture of grasses and willows at the edge of a small stream within the pinyonjuniper zone. Sagebrush and grease-wood are found on the immediate borders of the small valley. The stream is fed largely by runoff from irrigation and probably was very small or impermanent before irrigation. The Utah Ecological Researches crew trapped several specimens in similar habitat in the same general area (S.D. Durrant, personal communication ). Localities: COLORADO: _ La Plata C o . : F l o r i d a (Warren, 1942, p. 242). Archuleta C o . : NW 1/4 Sec. 23, T 32 N, R 6 W (1).

•

Erethizon dorsatum (Linnaeus) Porcupine

The porcupine is widespread and rather common as far south as the south ern rim of the Junction Land F o r m . It occurs also iii the Blanco Land Form. Either the animal or definite signs of its presence were observed in spruce forest, ponderosa pine -Douglas fir forest, relict conifer stands, pinyon -juniper, cropland, and riparian habitats. It may be most com mon in the pinyon-juniper zone.

ACCOUNTS OF SPECIES

Loca lities: COLORADO: La P la ta C o . : Allison (1 ). Arch uleta C o . : Gordon Creek near jct. with P iedra River (1). NEW MEXI CO: San Juan Co.: Lap la ta ( J . A . A l l e n , 1 893 , p . 70); Fruitland (Ba iley , 1931, p . 2 24 ) ; Fa rm ington (Ba iley, 193 1, p . 224 ); extrem e SW corner Sec. 14 , T 32 N, R 6 W (1 ); 4 m i. S an d 1/2 mi. E of Allison (1 ); n ear P in e River, Sec. 20, T 31 N, R 7 W (1 ); P in e River, NE 1 /4 Sec. 7, T 30 N, R 7 W (1 ); San Juan River, NW 1/4 Sec. 8 , T 3 0 N, R 7 W (1 ); E 1 /2 T 31 N, R 8 W(2 ); Blan co (Ba iley, 193 1, p . 224 ). Rio Arrib a C o . : S E 1 /4 of NW 1/4 S ec. 27 , T 32 N, R 6 W (1 ).

•

Ca n is la tra ns Say Coy ote

Con trol measures ha ve extirp a ted or g rea tly red uced the n um ber of coyotes in m any p ortion s of the West. The Junction and Blanco Land Forms with in th e study area would seem to fa ll in to th is categ ory . Coyotes are sa id to ha ve b een not uncomm on in earlier da ys, but n on e wa s seen nor h eard d urin g the p eriod of investigation north of the San Juan R i v e r . S outh of th e S an Juan , th e coy ote s t i l l is p resen t desp ite con trol m ea sures. One animal was found dead, probably from poison, in th e grassland s. Loca lities: NEW MEXI CO: Sa n Juan Co.: Lap la ta (Ba iley, 1931 , p . 3 16 ); Barker's Ca nyon, 40 m i. S and a little W of Dur ango (Ja ck son , 1951 , p . 3 02 ); Fruit -land (Ba iley, 19 31, p . 318 ); Dulce (Ba iley , 1931 , p . 319); Bla nco (Ba iley , 1931 , p.319 ); Cany on Blanco (Ba iley, 193 1, p . 319 ); 7 m i. S a nd 6 m i. W of Bloomfield, S ec. 4 , T 27 N, R 12 W (1); Largo (Ba iley, 19 31, p . 31 9 ).

•

Ca n is lup us Linna eus Gray Wolf

Th e wolf is not k nown to exist a t presen t with in th e study a rea. In th e past,

45

it probably ranged over the entire region at times. Localities: NEW MEXICO: San Juan Co.: Laplata (Goldman, 1944, p. 463). Rio Arriba C o . : 35 to 45 mi. SW of Dulce (Goldman, 1944, p. 463).

•

Vulpes fulva (Desmaret) Red Fox

Although commonly considered a montane form in the Southwest (Bailey, 1931; Warren, 1942), this fox also enters at least the pinyon-juniper zone in northwestern New Mexico. Records given by Bailey and a specimen in the University of New Mexico Collection of Vertebrates indicate a distribution along the San Juan River and in the broken mesa country to the east. Localities: NEW MEXICO: San Juan Co.: Shiprock (Bailey, 1931, p. 29 7); Fruitland (Bailey, 1931, p. 297); Liberty (Bailey, 1931, p. 297); Farmington (Bailey, 1931, p. 297); Canyon Largo, 5 mi. SE of Blanco (1).

•

Vulpes macrotis Merriam Kit Fox

The kit fox occurs in the country south of the Junction Land Form. Bailey (1931, p. 298) reports unsubstantiated ac -counts of this fox from Shiprock and from near Fruitland. The author has specimens from the grasslands south of the San Juan and has seen it in the Gallegos Canyon re gion. A rancher from the latter area re-ports it a s the commonest carnivore of the area. Localities: NEW MEXICO: San Juan C o . : 11 mi. E and 13 mi. S of Farmington (1); 16 mi. S and 1 mi. W of Farmington, Sec. 17, T 26 N, R 13 W (1).


46

•

Urocy on cin ereoargen teus (Schreber) Gray Fox

Th e g ray fox is comm on in the Junction Land Form of th e stud y area. It has b een seen in the lower p ortions of the p ond erosa p in e -Doug las fir zon e, in the crop land s surroun d ing Allison, and throughout the p in yon -jun ip er zone in bro ken count r y . I t may well occur in rough country south of th e San Jua n, a lthough no records a re a va ilab le. Loca lities: COLORADO: Archuleta C o . : Samb rito Creek n ea r Allison (1). NEW MEXI CO: San Juan Co.: Blan co (Bailey, 19 31, p . 302 ). Rio Arriba C o . : S an Juan R i v e r , S ec. 8, T 30 N, R 7 W (1 ).

•

• Bassariscus astutus (Lichtenstein) Ringtail No records of the ringtail are available for the San Juan Basin in New Mexico, though it occurs in southwestern Colorado, west and north of the study area. A small ring- tailed animal was seen crossing a dirt road near the junction of the San Juan and Pine R i v e r s , in San Juan Co. It was probably of this species, but as it was seen only fleetingly by car headlight, the possibility of its having been a young raccoon cannot be overruled. If this animal does occur in the study area, it may be expected about the canyons and rocky areas in the pinyon juniper of the Junction and Blanco Land Forms.

Ursus am ericanus Pa lla s Black Bear •

Bla ck b ea r were n either seen nor reported as present within the study area. Inhabitants did report, however, that they occurred th ere in th e pa st. I t is not unlik ely th a t som e sti ll live in or visit the reg ion, a t lea st in the north. S outh of the Junction Land Form, any occupancy in the pa st p robab ly wa s sp orad ic.

•

Ursus horrib ilis Ord Grizzly Bea r

Th ere seem s to b e no record of this sp ecies, p resen t or pa st, from the study a rea. However, in view of th e wide ranging of in d ividua ls an d of record s of their p resen ce in n ea rby h igh land s in the past, it ap pea rs lik ely tha t occasiona l ind ivid ua ls en tered th e reg ion . L o c a l i t i e s : COLORADO: Archuleta C o . : Na va jo Mtn., n ear Ch rom o (Warren, 1942, p. 38 ).

Procyon lotor (Linnaeus) Raccoon

Raccoons were present along the permanent watercourses of the study area, particularly where cliffs and rock debris afford shelter. Although not observed, they may occur far up the Piedra, Pine, and San Juan Rivers north of the study area. Localities: NEW MEXICO: San Juan C o . : Pine R i v e r , NE 1/4 of NE 1/4 Sec. 18, T 32 N, R 7 W (1); San Juan River Val -ley (Bailey, 1931, p. 348).

•

Mustela frenata Lichtenstein Long- tailed Weasel

An individual was found dead on a road amidst croplands near the junction of the ponderosa pine -Douglas fir zone with the pinyon- juniper zone. Bailey's records, which are not backed up by specimens, in dicate distribution through at least the major river valleys of the region.

47

ACCOUNTS OF SPECIES

L o ca l it i es : COLORADO: La Plata C o . : 2 m i. N of I gna cio (1 ). NEW MEXI CO: San Juan Co.: Fruitland (Ba i ley , 1931 , p. 328); Lib erty (Ba iley , 1 931 , p. 3 28 ); nea r Fa rm ing ton (Ba iley, 1931 , p . 3 28 ).

one mile north of Juanita, Archuleta C o . , C o l o . One specimen was trapped among rocks within the pinyon -juniper zone in New Mexico. Warren (1942, p. 77) states that they "do not go above the Transition zone, 8,000 feet being about the limit in C o l o r a d o . "

•

Mustela vison S ch reber Mink

The mink probably occurs , at least in sma ll numb ers, a long a ll th e permanent strea ms of th e study a rea . A sing le lower jaw was picked up in a pack rat nest; other wise, n o evid en ce wa s found. Ba iley's records app aren tly a re ba sed ma in ly on reports. Loca lities: COLORADO: Archuleta C o . : Gord on Creek n ear jct. with P ied ra River (1). NEW MEXI CO: ____________ Sa n Juan C o . : vicin ity of Lap la ta (Ba iley , 1 931 , p . 325); An ima s and San Juan Rivers n ea r Farmington (Ba iley , 1931 , p. 3 25 ); Liberty (Bailey, 1931, p. 325); Fruitland (Bailey, 1931, p.325).

•

Ta xid ea ta xus (S ch reber) Bad ger

Ba dgers were foun d with in the pinyon- juniper zone of the Junction Land Form an d a re probab ly common th rough out the study area . Loca lities: COLORADO: __La Plata C o . : Allison (1 ). Arch uleta C o . : NE of Ch rom o (Wa rren , 1942 , p. 8 5 ). NEW MEXI CO: _Sa n Juan Co.: San Juan River, NW 1/4 of S E 1 /4 Sec. 22 , T 32 N, R 6 W (1 ); P in e River, S E 1/ 4 of NE 1/4 S ec. 18, T 31 N, R 7 W (1 ); Lucero Ranch, W side of P ine River (1 ); throughout S an Juan Val - ley (of New Mexico) (Ba iley, 1931 , p .345).

•

Sp iloga le p utorius (Linn aeus) Spotted Sk unk

This small skunk was seen in open p ond erosa p in e forest two m il es east and

Localities: COLORADO: __ La Plata C o . : Bondad (Van Gelder, 1959, p. 288). NEW MEXICO: _ San Juan Co.: Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W (1).

•

Mephitis mephitis (Schreber) Striped Skunk

Striped skunks are common in river valleys, mountain f o r e s t s , and cultivated lands from the upper Piedra River in the north to the southern edge of the Junction Land Form; Bailey reports them from several places in the San Juan Valley south of this area. They were not found in sagebrush or grassland habitats, but may occur there. Localities: COLORADO: La Plata C o . : Allison, E 1/2 of NW 1/4 Sec. 15, T 32 N, R 6 W (1). Archuleta Co.: Gordon Creek near jct. with Piedra River (1); Deep Canyon, 4 mi. S and 1/2 mi. W of Chimney Rock (1); mouth of Sandoval Can-yon ( 1). NEW MEXICO: San Juan Co.: Sambrito Creek, S 1/2 Sec. 15, T 32 N, R 6 W (2); Pine River, SW 1/4 Sec. 8, T 30 N, R 7 W (1); Pine River, NW 1/4 Sec. 7, T 30 N, R 7 W (1); Fruitland (Bailey, 1931, p. 332); Blanco (Bailey, 1931, p. 333).



Felis concolor Kerr Mountain Lion

The only indication that the mountain lion presently enters the study area is a second hand report of a fight between two of these animals near the junction of the San Juan and Pine Rivers . It is likely that

48


m ost of the coun try a s far as the southern edge of the Junction Land Form is visited by th is b ig ca t on occa sion . About the third week of September, 19 62, F . W. Eddy and Bet h L. Dickey saw th e carca ss of an old ma le lion shot the sam e da y by Mrs. Eth ridg e, of Allison, Colo. ( F . W . E d d y , p ersona l communica t i o n , Jan . 1963 ). Sk ull and skin were to be turned over to th e Colorad o Fish and Game Departmen t for b oun ty . Th e locality was in S ec. 6 , T 3 2 N, R 5 W, Archuleta C o . , Colo.

• Lyn x rufus (Sch reb er) Bobcat Evidences of b ob ca ts were found in th e upper P ied ra River sp ruce forest, in p ond erosa p in e - Doug las fir forest, and with in th e p iny on -jun iper zone. Bailey records th em from th e Sa n Juan Valley south of th e Jun ction Lan d Form. They may b e exp ected an y wh ere n orth of the San Juan River and in areas of rough topography to th e south . Loca lities: COLORADO: _Archuleta C o . : Gord on Creek n ear jct. with Piedra River (1); near mouth of Archuleta Canyon (1 ); V illarea l Can yon, ab out 3 mi. SE of Juan ita (1 ). NEW MEXICO: San Juan Co.: Fruitland (Ba iley , 1931, p . 291). Rio Arriba C o . : Dulce (Ba iley , 1931 , p. 294).

• Cervus canad en sis Erxleben Wap iti Th e wap iti, or elk , has been observed a long S tollsteim er Creek n ear the mouth of Arch uleta Cany on . J. San d s, of the New Mexico Depa rtm en t of Game and Fish, says that sightings of this animal have been made on Ca rra ca s Mesa, in th e vicinity of the Colorado - New Mexico sta te line just east of th e Reservoir a rea. Th e Un iversity of New Mexico Collection of Verteb ra tes in cludes an antler

from the alluvium of an arroyo cut in Bancos Canyon, T 31 N, R 4 W, Rio Arriba C o . , New Mexico. However, there is a possibility that this specimen is of Pleisto cene, rather than Recent, age.

• Odocoileus hemionus (Rafinesque) Mul e Deer The mule deer was observed through out the study area to the southern edge of the Junction Land Form, but not south of that region. The mule deer may be found in riparian growth and croplands along permanent streams and also in ponderosa pine Doug las fir forest and pinyon-juniper far from any permanent water.

• Antilocapra americana (Ord) Pronghorn At one time, the pronghorn apparent ly was plentiful in the grasslands of northwestern New Mexico; at present, they are almost absent. It is doubtful if the species occurs north of the Blanco Land Form. It was not observed within the study area during the period of investigation, but small numbers are reported from the grasslands south of the San Juan. One pronghorn has been observed in the Reservoir ar ea ( F . W . E d d y , personal communication, Jan., 1963). The animal was seen several times from 1 June to 8 June 1962 on large sagebrush f la ts . That such occurrences are unusual was shown by the surprise of local workmen. It was first seen in the SE 1/4 Sec. 16, T 32 N, R 6 W; it was later sighted in the SW 1/4 Sec. 22, T 32 N, R 6 W. • Ammotragus lervia Pallas Barbary Sheep This North African bovid has been introduced in recent years into the Largo Canyon region east of the study area.

DISCUSSION

A vast biological change occurs between the northern checkpoint and the southern edge of the study area. At Gordon Creek, the northern checkpoint, there is a well watered forested area subject to heavy snows and frequent sub- zero temperatures in winter, frequent sh owers and relatively cool temperatures in summer. The growing season is b r i e f . To find these general moisture and temperature conditions at sea level, a journey of many hundred miles to the north would be required. In the south, the growing season is l ong, but precipitation is scanty. Hot days and rather cool nights in summer, cold temperatures in winter, are the general rule. A treeless expanse, frequently lack ing significant vegetative cover, is the re sult. Between these two extremes lies an interm ediate area where, in general, change in climate is quite gradual. The biota, governed in part by the climate, also changes rather gradually, allowing a finer distinc tion of distributional differences and, to some degree, ecological tolerances, than would be the case were the climatic changes more abrupt. Perhaps unfortunately, the land changes somewhat more abruptly than the climate. The sudden changes in eleva tion and topography wrought by the Junction Land Form and, to a lesser degree, the Blanco Land Form, serve to make more difficult the interpretation of climatic effects upon the biota --but at the same time, allow study of the effects of this portion of the environment upon organisms. Because of the changes in climate and physiography and probably a lso because

of interspecific relationships of the organ isms, a large number of life forms are un able to span the area from the upper Sono ran grasslands of the south to the boreal forests and meadows of the north. Taking into consideration only those organisms for which there is reasonable knowledge of dis tribution and ecological tolerances, it may be seen that in a transect from the area of the upper Piedra River to the grasslands in the vicinity of Gallegos Canyon, some twenty species appear in the more northerly areas but are absent in the extreme south; some twenty-nine species appear somewhere within the southern portions but are absent in the extreme north (Gordon Creek area). Four species seem absent both in the north and in the south, but occur be tween these two extremes. Some of these relationships are shown in Figures 9, 10, and 11. One species, represented by two nominal sub -species, is present in the north and south, but has not been found in the central por tion of the study area. Eight groups in which the members possess approximately common range limitations within such a transect may be tenta tively delineated. A ninth group spans the area. Composition of these groups is given in Figure 12. The factors affecting the composition of the var ious groups cannot be sorted out with any great degree of accuracy at pres ent, but possible explanations have been advanced for individual species in some cases in the specific or generic accounts. In some groups, part or all of the organ-isms concerned probably have a common background, having evolved to fit a similar set of circumstances (for example, the

Fig. 11. Approximate distributions of member species of Group IX.

DISCUSSION

53

total geographical ranges of the members of Group V would seem to indicate similar origins). In other cases, similar environm e n t a l re qu i r e me n t s a p p e a r t o li m i t c r e a ture s of wi de ly se parate histori e s (as, for example, Neotoma mexicana and Eutamias quadrivittatus of Group IV—probably limited because of cover requirements). I n yet o t h e r c a se s , c o m p e t i ti o n m a y p r e ve n t e x tensions of an animal's range into an area where it is otherwise physically able to

exist (thus Sceloporus graciosus may be prevented from entering portions of the Junction Land Form because of the prese nce of S. undulatus). The se and othe r possible conditions account for the pattern of distribution within the study area—it will be many ye ars, howe ve r, be fore suffcie nt data are available to explain adequately the principle factors causing each species to form its pattern of distribution.

Fig. 12. List of species composing nine groups of associated animals.

Group I . - Limits not within transect. Ambysto ma tigrinum Buf o woodhousei

Rana pipiens Thamnophis elegans

Reithrodon tomys megalo tis Peromyscus maniculatus

T axidea taxus Mephitis mephitis

Group II. - Southern limits within transition l i f e - z o n e . Buf o boreas Sorex vagrans

Eutamias minimus Thomomys talpoides

Citellus later alis Neo toma cinerea orolestes

Group III. - Southern limits near northern edge Junction Land Form. Lampropeltis doliata Sylvilagus nuttalli

Marmo ta f laviventris Micro tus mon tanus

Micro tus longicaudus Zapus princeps

Cervus canadensis

Group IV. - Southern limits near southern edge Blanco Land Form. Pseudacris nigrita Eutamias quadrivittatus

Citellus variegatus Castor can adensis

Neo toma mexicana Ondatr a zibe thicus

Erethizon dorsatum Urocyon cinereoargenteus

Group V. - Northern limits south of the San Juan R i v e r . Holbrookia maculata

Cnemidophorus inornatus

Arizona elegans

Citellus spilosoma

Group VI . - Northern limits within Blanco Land Form. U ta stansburiana Cnemidophorus tigris

Citellus leucurus Perognathus f lavus

Dipodomys ordi Dipodomys spec tabilis

Neo toma cinerea arizonae Vulpes macro tis Antilocapra americ ana

Group VII. - Northern limits near north edge of Junction Land Form. Crotaphytus collaris Sceloporus graciosus

Masticophis taeniatus Pipistrellus hesperus

Sylvilagus auduboni Perognathus apache

Peromyscus crinitus Onychomys leucogaster Neo toma stephensi

Group VIII. – Northern limits in northern portion of Arboles Land Form or north of main study area. Sceloporus undulatus Phrynosoma douglassi

Thamnophis cyrtopsis. Crotalus viridis

Antrozous pallidus Lepus calif ornicus

Thomomys bo ttae Neo toma albigula

Group IX. - Northern and southern limits within transect. Cnemidophorus velox

Peromyscus boylii

Peromyscus truei

Micro tus pennsylvanicus

A P P E N D I X

A

THE FISHES OF THE NAVAJO RESERVOIR DISTRICT by WILLIAM J. KOSTER

The following list is based upon an examination of over 3, 100 specimens captured during 1959, 1960, and 1961. Fish were take n by se ine , e le ctric shocke r, gill ne t, fry ne t, hook a nd line , and rote none , The last was use d as a part of a fish-manage m e n t p r o g r a m de s i g ne d to re mo ve , by th o r ough poisoning, the "rough" fish prior to stocking the new lake with game species. Collections were made at various points in the San Juan and Pine Rivers from the Colorado-New Mexico Boundary down to the dam site, as well as in the only small stream in t h e i m p o u n d m e n t a r e a , S a m b r i t o C r e e k . The following individuals in one way or ano t he r a i de d i n s e c u r i n g s pe ci me n s : D. D a vi e s , A . E . D i t t e r t , J r . , A . H . H a r r i s , J . M c C l e l l a n d, D . M a r ti n , H . O l s o n, an d M . S e i b e l . T h e i r a i d i s g r a t e f u l l y a c k n o w l e d g ed.

A total of fourteen species, six native and eight introduced, was found in the area. The native species include: the speckled dace, Rhinichtys osculus (Girard); the bonytail, Gila robusta Baird and Girard; the Colorado squawfish, Ptychocheilus lucius Girard; the flannelmouth sucker, Catostomus latipinnis Baird and Girard; the blue-head sucker, Pantosteus delphinus (Cope); and the mottled sculpin, Cottus bairdi Girard. Most of these species were common and distributed throughout the area. The squawfish was the exception. O n l y s i x specimens were taken and all were from the San Juan proper. The introduced species include: the brown trout, Salmo trutta Lin-

naeus; the carp, Cyprinus carpio Linnaeus; the fathead minnow, Pimephales promelas Rafinesque; the white sucker, Catostomus commersoni (Lacepee); the channel catfish, Ictalurus punctatus (Rafinesque); the blue catfish, Ictalurus melas (Rafinesque); and the blue gill, Le pomis mac r ochirus Raf ine s que . Two hybri d combinati o ns we re also found. One sucke r was inte rp re te d as a h y b r i d b e t w e e n C a t o s t o m u s c o m m e r s o n i and Pantosteus delphinus and another as a cross between Catostomus latipinnis and P a n t o s te u s d e l p h i n u s. W i t h t he e xc e pt i o n of the blue catfish, which was observed among a catch of channel catfish taken by a fisherman, specimens of the above are preserved at the University of New Mexico.

In a discussion of the possibility of using such fish re mains as might be found in archaeological ruins as clues to past conditions in the region, Koster (1961) listed ten species known to occur natively in the up pe r C o l o r a d o R i v e r B a s i n . O f t h e se te n , e i g h t m i g h t r e a so n a b l y h a v e be e n e x pe c t e d i n t h e N a v a j o Re se rv o i r Di s t ri c t o n ge ographic ground. Six actually were found, and it is possible that two species, the cutthroat trout, Salmo clarki Richardson, and the humpback sucker, Xyrauchen texanus ( A b b o t t ), w e re p re se n t a n d mi ss e d. Th e discovery in the Pine River of the brown trout, a taxonomic and ecologic cognate of the cutthroat suggests that conditions in the Pine R i v e r a t le as t , a r e n o t f a r f r o m b e i n g suitable for cutthroats. Since tributary streams a short distance to the north are

THE FISHES OF THE NAVAJO RESERVOIR DISTRICT

inhabited by trout and the cutthroat is the native trout of the area, it is conceivable that, particularly in winter, a few cutthroat: might work into the area. There are, however, no records or reports of cutt hroats ever having been taken within the impoundme nt are a. The pre se nce of the humpback sucker is suggested by an angler's report of the occasional capture of a "humpie", a humpbacked fish. Because this was the only species reported but not taken, crew members of the New Mexico State Game and Fish Department who aided in the preimpoundment poisoning of the area were urged to be on a speci al look-out for "humpies." They found none.

At present, despite the existence of a few brown trout in the Pine River, all the waters in the impoundment area would be classified by fisheries' biologists as non-trout waters. Existing conditions, however, are so close to those tolerated by trout that if trout remains should be found in the archaeological sites, it would

55

be rash to conclude that there had been a major change in the ecology of the area. O t he r t ha n t he i n t r o du c e d c o m pe t i t o r s , the chief hindrance to trout appears to be temperature. The presence of trout in the Pine River and the persistence into J u l y o f t e mpe r a t u re s low e no u g h f o r t r o u t in the San Juan River just above its confluence with the Pine indicate that a relatively slight change in regional temperature would permit trout to survive throughout the area. I ndeed, it is possible that s o m e t r o u t w e r e a b l e t o e x i s t t h r o u g h o u t the impoundment area before the activities of white man modified the streams. The reduction of stream cover by cutting and grazing and the reduction of stream flow b y d i v e r t i ng w a t e r f o r i r r i g a t i o n h a v e u n doubtedly resulted in an elevation of the s t r e a m t e m p e r a t u r e s . C o n v e r s e l y , j u s t as only a minor change in temperature would be required to permit t rout to per si st ove r t h e e nt i re ar e a, s o a rel a t i v e l y minor shift in the opposite direction would completely eliminate them.

APPENDIX B BIRDS NOTED IN THE NAVAJO RESERVOIR DISTRICT by DAVID M. NILES Pa rts of th e p eriod from July 21 to August 24 , 1961 were sp en t n ea r or within the projected e mpoundment area of the Navajo R e s e r v o i r , an d a record wa s kep t of all birds seen . Th e following list p resen ts the locality, da te and n oted hab ita t of a ll b ird s recorded, an d supp lem en ts p revious work d one in the a rea (Dittert, et a l, 1961 , pp . 3 1 -3 2; White an d Beh le, 1961 ). In forma tion on th e b reed ing status of a species in the a rea can be found in White and Behle (1961) for all but four of the b ird s listed h ere. Sha rp- sh inn ed hawks and Ma rsh Ha wk s are p rob ab ly p ermanent resi d en ts; Ma cGillivra y' s Wa rb le rs and Wilson's Wa rb lers are p rob ab ly tran sien ts. Other than ma rk ing record s involving im ma ture birds with a n asterisk, I ha ve mad e no fur ther a ttem p t to sep ara te p roba b le resid ent and tran sien t species. For p recise loca lities of Laboratory of An th ropolo g y ( L A ) sites read ers a re re ferred to Dittert, et a l (op cit. ). Ny cticorax ny cticora x (Linna eus) Bla ck - crown ed Nig h t Heron *Near Allison, Aug. 10, marshy stream surround ed by farm land .

Cathartes aura (Linnaeus) Turkey Vulture Near Ignacio, July 23, farmland; rim of Pine River Canyon above LA 4 2 6 9 , Aug. 14, pinyon- juniper woodland; LA 4380, Aug. 18, big sage and cottonwoods along r i v e r , pinyon-junipe r on nearby slopes. Accipiter striatus Vieillot Sharp -shinned Hawk Pine River at LA 4269, Aug. 11, ri parian woodland. Buteo jamaicensis (Gmelin) Red- tailed Hawk Approx. 1 mi. NW of Allison, Aug. 21, farmland; T 27 N, R 11 W, San Juan

N.M.,

Co.,

Aug. 24, big sage.

Aquila chrysaetos (Linnaeus) Golden Eagle *Approx. 1 mi. N of Allison, Aug. 17, mixed farmland and pinyon -juniper. Circus cyaneus (Linnaeus) Marsh Hawk Near Ignacio, Aug. 23, farmla nd.

Anas platyrhynchos Linnaeus Ma lla rd

Falco sparverius Linnaeus Sparrow Hawk

App rox. 1/2 m i. NE of Alliso n, Aug. 10 , sma ll stream in farm land .

Near Allison, J uly 23, Aug. 10, farmland; approx. 1 mi. N of Allison, Aug. 21, mixed farmland and pinyon -juniper woodland.

BIRDS NOTED IN THE NAVAJO RESERVOIR DISTRICT

57

Ca llip ep la squama ta ( V i g o r s ) S ca led Qua il

Selasphorus platycercus (Swains on) Broad -tailed Hummingbir d

*T 27 N, R 11 W, San Juan C o . , N . M . Aug. 24 , b ig sage.

T 27 N, R 11 W, San Juan C o . , N.M., July 24, mixed juniper -big sage.

Ra llus lim icola V ieillot V irg in ia Ra il *Approx. 1 m i. NW of Allison, Aug. 21, sma ll ca tta il ch ok ed stream in farmland. Charadrius vociferus Linnaeus Killd eer Allison, Aug. 10 , 'm uddy margin of a brush and cattail lined stream in farmland. Actitis. macularia (Linnaeus) Sp otter Sandp iper P ine River a t LA 4 2 6 9 , Aug. 14, s a n d y river ma rg in; LA 438 0, Aug . 18, river mar g in. Zenaidura macroura (Linnaeus) Mourning Dove Allison, July 23, Aug. 10 , farmland; T 27 N, R 11 W, San Juan C o . , N . M . , J u l y 23, Aug . 2 , 23, steep ly cut wa sh es, sparse jun ip er; rim of P in e River Ca nyon above LA 42 69, Aug. 14 , p iny on -jun ip er. Bubo virginianus (Gmelin) Grea t Horn ed Owl T 27 N, R 11 W, San Juan C o . , N.M., July 24, steep ly cut wash , spa rse juniper; P ine River a t LA 4 2 6 9 , Aug . 1 4, riparian wood land . Ch ord eiles m in or ( F o r s t e r ) Comm on Nigh tha wk T 2 7 N, R 11 W, San Juan C o . , N.M., July 24 , Aug . 2 , steeply cut washes, sparse jun ip er; Allison, Aug. 16 , 23 , farmland.

Selasphorus rufus (Gmelin) Rufous Hummingbird LA 4380, Aug. 18, mixed big sage and riparian woodland. Megaceryle alcyon (Linnaeus) Belted Kingfisher Allison, Aug. 10, brush lined st ream; Piedra River near Arboles, Aug. 22, riparian woodland. Colaptes cafer (Gmelin) Red- shafted Flicker Allison, Aug. 10, 16, riparian thickets, pinyon-juniper and farmland; Pine River at LA 4269, Aug. 11, riparian woodland; LA 4380, Aug. 18, pinyon -juniper and riparian woodland. Asyndesmus l e w i s (Gray) L e w i s ' Woodpecker Piedra River near Arboles, Aug. 9, 22, riparian woodland. Dendrocopos villosus (Linnaeus) Hairy Woodpecker Allison, Aug. 10, telephone pole in farmland; Pine River at LA 4269, Aug. 14, riparian woodland; T 27 N, R 11 W, San Juan C o . , N.M., Aug. 23, mixed juniper big sage. Dendrocopos pubescens (Linnaeus) Downy Woodpecker Allison, Aug. 17, cottonwoods border ing field.

58


Ty ran nus vertica lis Say Western Kin gb ird

Hirundo rustica Linnaeus Barn Swallow

Allison, July 21, d eciduous trees in town ; P iedra River n ear Arb oles, Aug . 22, ripa rian wood land .

Near Ignacio, July 23, farmland; Piedra River near Arboles, Aug. 9, under bridge over r i v e r ; Allison, Aug. 10, farmland, LA 4380, Aug. 18, over r i v e r .

My ia rchus cinera scen s (La wrence) Ash- throa ted Flyca tcher T 27 N, R 11 W, San Juan C o . , N.M., July 24, steep ly cut wash , spa rse juniper. Sa yorn is sa ya (Bonapa rte) Sa y's Ph oeb e Allison, Aug. 10 , fa rm lan d; LA 4380, Aug. 18 , riparian wood lan d. Contopus sordidulus Sclater Western Wood P ewee P ine River a t LA 4269 , Aug. 14 , ri pa ria n wood lan d; LA 4380 , Aug . 18 , riparian wood land .

Erem oph il a a lp estris (Lin naeus) Horn ed Lark T 27 N, R 11 W, San Juan C o . , N.M., July 24, Aug. 24 , ba re a rea in steep ly cut wa sh and op en area s am ong b ig sag e. Tachycineta thalassina (Swains on) V iolet -g reen S wa llow Nea r I gna cio, July 2 3, fa rm la nd; Alli son, Aug . 10, 15, fa rm lan d; LA 438 0, Aug. 18 , over r i v e r ; T 27 N, R 11 W, San Juan Co., N . M . Aug . 24, b ig sag e and spa rse juniper.

Petrochelidon pyrrhonota ( V i e i l l o t ) Cliff Swallow Piedra River near Arboles, Aug. 9, under bridge over r i v e r . Aphelocoma coerulescens (Bosc) Scrub Jay Pine River at LA 4 2 6 9 , Aug. 11, riparian woodland; approx. 1 1/2 mi. N of Allison, Aug. 16, pinyon- juniper; LA 4380, Aug. 18, pinyon- juniper. Pica pica (Linnaeus) Black- billed Magpie Allison, Aug. 10, farmland; Pine River at LA 4269, Aug. 14, pinyon- juniper; Piedra River near Arboles, Aug. 22, riparian woodland. Corvus corax Linnaeus Common Raven T 27 N, R 11 W, San Juan C o . , N.M., July 24, sparsely vegetated canyon; Pine River at LA 4 2 6 9 , Aug. 11, pinyon -juniper; LA 4380, Aug. 18, mudflats in r i v e r . Gymnorhinus cyanocephala Wied Pinyon Jay Pine River at LA 4269, Aug. 11, pinyonjuniper; approx. 1 1/2 mi. N of Allison, Aug. 16, pinyon-juniper.

S telg idop tery x ruficollis ( V i e i l l o t ) Rough- winged S wa llow

Parus atricapillus Linnaeus Black- capped Chickadee

Allison, Aug. 16 , fa rm lan d; LA 4380, Aug. 18 , over r i v e r .

Pine River at LA parian woodland.

4269,

Aug. 14, ri-

BIRDS NOTED IN THE NAVAJO RESERVOIR DISTRICT

59

Parus inornatus Gambel Plain Titm ouse

Turdus migratorius Linnaeus Robin

Rim of P in e River Ca nyon ab ove LA 4269, Aug. 14 , p iny on -jun ip er; LA 438 0, Aug. 18 , p iny on -jun ip er.

Allison, July 21, Aug. 10, deciduous t r e e s , riparian thickets, pinyon- juniper; Pine River at LA 4269, Aug. 11, 14, riparian woodland.

Psaltriparus minimus (Townsend) Comm on Bush tit Rim of P in e River Ca nyon , a bove LA 4269, Aug. 14 , p iny on -jun ip er; LA 438 0, Aug. 18 , p iny on -jun ip er. Sitta ca rolin en sis La tham White -brea sted Nutha tch Allison, July 21, d eciduous trees in town; Rim of P ine River Cany on ab ove LA 4269, Aug. 14 , p iny on -jun ip er; 1 1 /2 m i. N of Allison, Aug. 16 , p iny on-jun ip er.

Sialia mexicana Swains on Western Bluebird Allison, July 21, Aug. 16, deciduous trees in town, farmland; *Pine River at LA 4269, Aug. 14, riparian woodland; LA 4380, Aug. 18, riparian woodland. Sialia currucoides (Bechstein) Mountain Bluebird Allison, Aug. 10, farmland.

Troglody tes a ed on V ieillot House Wren

Polioptila caerulea (Linnaeus) Blue- gray Gnatcatcher

P ine River a t LA 4 2 6 9 , Aug . 1 1, b rushy under story of ripa rian wood land ; app rox. 1 mi. N of Allison , Aug . 21 , stream sid e veg etation in m ixed p iny on- jun ip er, fa rm land .

Pine River at LA 4269, Aug. 11, 14, brush underneath cottonwoods; LA 4380, Aug. 18, riparian woodland and big sage; T 27 N, R 11 W, San Juan C o . , N . M . , A u g . 23, mixed juniper and big sage.

Catherpes mexicanus (Swainson) Canyon Wren P ine River a t LA 4269 , Aug. 11 , rocky slope in p inyon- jun iper. Salpinctes obsoletus (Say) Rock Wren T 27 N, R 11 W, San Juan C o . , N.M., July 23, Aug. 23 , sp arsely veg eta ted wa sh es, some jun ip er; P in e River a t LA 4269 , Aug . 11, rocky slope in p inyon-jun ip er.

Lanius ludovicianus Linnaeus Loggerhead Shrike T 27 N, R 11 W, San Juan C o . , N.M., July 24, mixed juniper and big sage. Sturnus vulgaris Linnaeus Starling Allison, Aug. 15, trees in town.

Vermivora virginiae (Baird) Virginia's Warbler Mimus polyglottos (Linnaeus) Mockingb ird Allison, Aug. 10 , riparian th ick ets.

Pine River at LA 4269, Aug. 14, brushy understory of riparian woodland; T 27 N, R 11 W, San Juan C o . , N . M . , A u g . 23, mixed juniper and big sage.

60


Dendroica petechia (Linnaeus) Yellow Wa rb ler

Agelaius phoeniceus (Linnaeus) Red Winged Blackbird

Allison, July 21, Aug. 16 , deciduous trees in town and low rip arian vegetation; P ine River a t LA 4269 , Aug. 11 , 14, brushy und erstory of rip arian wood land ; LA 4380, Aug. 18 , riparian wood lan d .

Near Ignacio, July 23, farmland and cattail marshes; Allison, Aug. 10, 15, 21, farmland and cattail marshes.

Dendroica n ig rescens (Town send ) Bla ck - th roa ted Gray Wa rb ler P ine River a t LA 4269 , Aug. 14, brushy und er story of ripa rian wood land and pinyonjun ip er; T 27 N, R 11 W, S an Juan Co., N.M., Aug. 24 , m ixed jun ip er an d b ig sage. Op ororn is tolm iei (Town send ) Ma cGillivray 's Wa rb ler P ine River a t LA 4269 , Aug. 14, brushy und erstory of rip arian wood land ; T 27 N, R '11 W, Sa n Juan C o . , N.M., Aug . 2 3, mix ed jun ip er and b ig sage. Wilson ia pusilla (Wilson ) Wilson's Wa rb ler

Icterus bullocki (Swains on) Bullock's Oriole Approx. 1 mi. N of Allison, Aug. 16, riparian growth and pinyon- juniper. Euphagus cyanocephalus (Wagler) Brewer's Blackbird Near Ignacio, July 23, farmland; Allison, Aug. 10, 21, farmland. Piranga ludoviciana (Wilson) Western Tanager Rim of Pine River Canyon above LA 4269, Aug. 14, pinyon- juniper. Pheucticus melanocephalus (Swainson) Black- headed Grosbeak

Allison, Aug. 10, farmland; approx. P ine River a t LA 4269 , Aug. 14, brushy 1/2 mi. N of Allison, Aug. 21, riparian und er story of ripa rian wood land ; Allison, Aug. thickets. 15 , 16 , 21, d ecid uous trees and low ri parian vegeta tion. Guiraca caerulea (Linnaeus) Blue Grosbeak Pa sser d omesticus (Linna eus) House Sp arrow Allison, July 21– Aug . 21 , farmyards an d a round d welling s. Sturnella neglecta Audubon Western Mead owla rk Nea r I gna cio, July 2 3, fa rmland; Allison, Aug . 10 , fa rm la nd. Xanthocephalus xanthocephalus (Bonaparte) Yellow -h ead ed Bla ckb ird

Allison, Aug. 10, brush along small stream surrounded by farmland; approx. 1/2 mi. N of Allison, Aug. 21, riparian thickets. Carpodacus mexicanus (Muller) House Finch T 27 N, R 11 W, San Juan C o . , N.M., July 24, sparse juniper; LA 4380, Aug. 18, mixed big sage and riparian woodland. Spinus pinus (Wilson) Pine Siskin

Allison, Aug. 15 , fa rm lan d. Approx. 1 mi. N of Allison, Aug. 16,

BIR DS NOTED IN T HE NA VA JO RESERVOIR DIS TR ICT

61

Spinus tristis (Linnaeus) Am erican Goldfinch

Amphispiza bilineata (Cassin) Black - throated Sparrow

Allison, Aug. 10 , brush a long road and sma ll stream in fa rm land .

*T 27 N, R 11 W, San Juan C o . , N.M., July 23, Aug. 2, sparse juniper in deeply cut washes, mixed juniper and big sage.

Spinus psaltria (Say) Lesser Gold fin ch Allison, July 21, Aug. 10, 16, deciduous trees in town, b rush y areas in farmland and ripa rian th i ck ets. P ip ilo ery th roph tha lmus (Lin na eus) Rufous-sided Towh ee *P ine River a t LA 42 69, Aug . 11, brushy understory in riparian woodland. P ooecetes g ram in eus (Gm elin ) V esper Spa rrow Allison, Aug. 10 , brushy th ickets a long sma ll stream . Ch ond estes g rammacus (Say ) La rk Spa rrow Allison, Aug. 15 , brush on edge of field.

Spizella passeri na (Bechstein) Chipping Sparrow *Allison, Aug. 10, 15, brushy areas be side road and mixed pinyon- juniper, big sage; rim of Pine River Canyon above LA 4269, Aug. 14, pinyon -juniper; approx. 1 mi. N of Allison, Aug. 16, 21, brushy areas along roads or stre ams. Spizella breweri Cassin Brewer's Sparrow Allison, Aug. l0, brushy area beside road; T 27 N, R 11 W, San Juan Co., N.M., Aug. 24, big sage.

BIBLIOGRAPHY

Allen, J . A . 1893 List of Mammals Collected by Mr. Charles P. Rowley in the San Juan Region of Colorado, New Mexico and Utah with Descriptions of New Species. Bulletin American Museum of Natural History, Vol. 5, pp. 69 -84, New York. Bailey, V. 1915 Revision of the Pocket Gophers of the Genus Thomomys. North American Fauna, Vol. 39, pp. 1-136, Washington, D.C. 1931

Mammals of New Mexico. North American Fauna. Vol. 53, pp. 1 -412, Washington, D.C.

Cary, M. 1911 A Biological Survey of Colorado. North American Fauna, Vol. 33, pp. 1-256, Washington, D.C. Dittert, A . E . Jr., J..J.Hester, and F . W . Eddy 1961 An Archaeological Survey of the Navajo Reservoir District, Northwestern New Mexico. Monograph of the School of American Research and Museum of New Mexico, No. 23, Santa Fe. Finley, R . B . J r . 1958 The Wood Rats of Colorado: Distribution and Ecology. University of Kansas Publications Museum of Natural History, Vol. 10 (6), pp. 213-522, Lawrence, Kansas.

Goldman, E . A . (cont'd) 1933 New Mammals from Arizona, New Mexico, and Colorado. Journal Washington Academy of Sciences, Vol. 23, pp. 463-473, Washing-ton, D.C. 1944 Classification of Wolves. In: The Wolves o f North America, by Young, S.P., and E . A . Goldman, pp. 387-507. American Wildlife Institute, Washington, D. C. Hall, E.R., and K.R.Kelson 1959 The Mammals of North America. Ronald Press, New York. Hardy, E . L . 1941 Climate of New Mexico. In: Climate a nd Man, Yearbook of Agriculture, pp. 1011 -1024, U.S.Department of Agriculture, Wash ington, D.C. Harris, A.H., and J.S.Findley 1962 Status of Myotis l ucifugus phasma and Comments on Variation in Myotis yumanensis. Journal Mammalogy, Vol. 43 (2), pp. 192-199, Lawrence, Kansas. Hoffmeister, D . F . 1951 Taxonomic a nd Evolutionary Study of the Pinon Mouse, Peromyscus truei. Illinois Biological Monographs, Vol. 21 (4), Urbana Illinois.

Gittings, E . B . 1941 Climate of Colorado. In: Climate and Man, Yearbook of Agriculture, pp. 798-808, U.S.Department of Agriculture, Washington, D.C.

Hollister, N. 1916 A Systematic Account of the Prairie Dogs. North American Fauna, Vol. 40, pp. 1-37, Washington, D.C.

Goldman, E . A . 1910 Revision of the Woodrats of the Genus Neotoma. North American Fauna, Vol. 31, pp. 1-124, Washington, D.C.

Howell, A . H . 1914 Revision of the American Harvest Mice (Genus Reithrodontomys). North American Fauna, Vol. 36, pp. 1-97, Washington,D.C.

1932a Two New Rodents from Arizona. Proceedings Biological Society of Washington, Vol. 45, pp. 89-91, Washington, D.C.

1915 Revision of the American Marmots. North American Fauna, Vol. 37, pp. 1 -80, Washington, D.C.

1932b Revision of the Woodrats of the Neotoma lepida Group. Journal Mammalogy, Vol. 13, (1), pp. 59-67, Lawrence, Kansas.

1929 Revision of the American Chipmunks (Genera Tamias and Eutamias). North American Fauna, Vol. 52, pp. 1-157, Washington, D.C.

BIBLIOGRAPHY

Howell, A. H. (cont'd) 1938 Revision of the North American Ground Squirrels, with a Classification of the North American Sciuridae. North American Fauna, Vol. 56, pp. 1-256, Washington, D.C. Jackson, H . H . T . 1951 Classification of the Races of the Coyote. In: The Clever Coyote, by Y oung, S.P. and H . H . T . Jackson, pp. 227-341. Stackpole Co., Harrisburg, Pennsylvania, Wildlife Institute, Washington, D.C. Koster, William J. 1961 Fish as Indicators of Past Environments pp. 28-29, In: An Archaeological Survey of the Navajo Reservoir District Northwestern New Mexico. Dittert, A. E. Jr, J, J. Hester, F. W.Eddy. Monographs of the School of American Research and the Museum of New Mexico, Number 23, Santa Fe, New Mexico. Maslin, T . P . 1959 An Annotated Check List of the Amphibians and Reptiles of Colorado. University of Colorado Studies, Series in Biology, Vol. 6, Boulder, Colorado. Nelson, E, W, 1909 The Rabbits of North America. North American Fauna, Vol. 29, pp. 1-314, Washington, D.C. Osgood, W.H. 1909 Revision of the Mice of the American Genus Peromyscus. North American Fauna, Vol. 28, pp. 1-285, Washington, D.C.

63

Rodeck, H.G. 1961 Another Spotted Bat from New Mexico. Journal of Mammalogy, Vol. 42, p. 401, Lawrence, Kansas. Schmidt, K, P, 1953 A Check List of North American Amphib ians a nd Reptiles. American Society Ichthyologists and Herpetologists, University Chicago Press, Chicago, Illinois. Setzer, H. W. 1949 Subspeciation in the Kangaroo Rat, Dipodomys ordii. University Kansas Publica tions Museum Natural History, Vol. 1 (3), pp. 47 3-573, Lawrence, Kansas. Stebbins, R . C . 1954 Amphibians and Reptiles of WesternNorth America. McGraw-Hill, New York. Van Gelder, R.G. 1959 A Taxonomic Revision of the Spotted Skunks (Genus Spilogale). Bulletin American Museum Natural History, Vol. 117 (5), pp. 229-392, New York. Warren, E . R . 1942 The Mammals of Colorado. University Oklahoma Press, Norman, Oklahoma. White, C,M., and W.H. Behle 1961 Birds of Navajo Reservoir Basin in Colorado and New Mexico, 1960. In: Ecological Studies of the Flora and Fauna of Navajo Reservoir Basin, Colorado and New Mexico, pp. 129-154. University of Utah Anthropological Papers, No. 55, Salt Lake City.

LIST OF PREVIOUS NAVAJO PROJECT STUDIES

Study Number 1.

Dittert, A . E ., Jr. 1958 Preliminary Archaeological Investigations in the Navajo Project Area of Northwestern New Mexico. Museum of New Mexico Papers in Anthropology, No. 1 . The Museum of New Mexico and the School of American Research, Santa Fe.

2.

Dittert, A . E ., Jr, J .J . Hester, and F . W . Eddy 1961 An Archaeological Survey of the Navajo Reservoir District Northwestern New Mexico . Monograph of the School of American Research and the Museum of New Mexico, No . 23, Santa Fe.

3.

Greminger, H .C . (assembler) Papers from a Training Program in Salvage 1961 Archaeology . Museum of New Mexico Papers in Anthropology, No . 3, Santa Fe.

4.

Eddy, F . W. 1961 Excavations at Los Pinos Phase Sites in the Navajo Reservoir District . Museum of New Mexico Papers in Anthropology, No . 4, Santa Fe.

5.

Hester, J .J. 1962 Early Navajo Migrations and Acculturation in the Southwest . Museum of New Mexico Papers in Anthropology, No . 6, Santa Fe.

6.

Schaafsma, P. Rock Art in the Navajo Reservoir District . Museum 1963 of New Mexico Papers in Anthropology, No . 7, Santa Fe .