RELATIONS BETWEEN COMMON DORMICE ...

lind Siebenschlti[er (Glis

FOLIA ZOOLOGICA - 44(4): 289-296 (1995)

lkasten in1 SUdharz der

1. InJ., 7( 10): 34 J-348. 1959: Uber Morphologie HaselInaus (Muscardinus 1 Polen. Acta theriol., (5):

9: OreshnikoYaya sonya ~llanarius L.) v LatYijskoj ,atvijskoj SSR i sopredel[Colnmon dortnouse ellanarius L.) in Latvian of Latvian SSR and adja-

RELATIONS BETWEEN COMMON DORMICE (MUSCARDINUS AVELLANARIUS) AND OTHER OCCUPANTS OF BIRD NEST-BOXES IN LIr-rHUANIA Rilnvydas JUSKAITIS

. Riga, 2: 233-236 (in

ESCH, A.v., 1960: Del' ;tis glis L.). lena, 196 fJfJ.

Received January 23, 1995 Accepted l\!lay 23, 1995

Institute of Ecology, Academy of Sciences of Lithuania, Vilnius Abstract Relations between Common dormice (Muscardinus o\'ellanarills L.) and other occupants of nestboxes are cOlnpetitive. Competition for nest-boxes between Ivl. avellanarius and the Pied flycatcher (Ficedula hYfJoleuca) occurs in the form of destroying their nests. The Great tit (Pants 17zajor) and Blue tit (P. caerllleus), having later breeding tiInes and being more aggressive, are not affected by dormice. Nest-boxes occupied by bUlnblc bees, wasps and hornets are not used by 1\1avellanariliS. In autumn, M. avellanariliS are displaced frOlTI nest-boxes by Yellow-necked lnice (Apodelnus flavicollis). Dorn1ouse nests remaining from the previous year have a negative ilnpact on roosting and breeding of hole-nesting birds, except of F. hypoleuca, but encourage nest-box occupation by bumble bees.

Introduction :i\1any published reports indicate that Conlnlon dornlice (MuscarLlinus avellanarius L.) occupy artificial bird nest sites, where they destroy nests and clutches of sIllall hole-nesting birds, eat their young and even adult birds (5 i d 0 row i c z 1959; Straus 1959; Pielowski & Wasilewski 1960; J e z e r s k as] 96]; L 0 h r I ] 960; L 0 zan 1970; L i k hac h e v 197 I ; S c h u I z e 1973, 1986; G v 0 z d a k & S j In 0 c h k 0 I 977; Jus k a i tis 1993 and others). However, other aspects of these relationships have been little investigated. In fact there are no data on relations between M. avellanarius and other s111all 1l1alnmal species or social insects, occupying nest-boxes. Very little attention has also been paid to the effect of previous year's M. avellanarius nests in nestboxes on hole-nesting birds and other occupants of the same nest-boxes.

Study Area, Material and lVlethods

500 Vilnius, Lithuania

A comprehensive investigation on relations bet\veen M. avellanarius and other occupants of artificial bird nest sites have been carried out at t~TO study sites: I) site A - studied in 1980-1990. South western Lithuania, Sakiai district; a nliddle-aged, mixed forest with high tree and shrub diversity. The dOtninant tree species are birch (Betula 11endula), Norway spruce (l~icea abies), black alder (Alnus glutinosa), in some places aspen (POIJulus trelnula) and ash (Fraxinus excelsior). T'he understorey contains 111any hazel ((:'orylus avellana) and buckthorn (Frangula alnus) shtubs. 289

2) site B - studied in 1984-1993 is in Eastern Lithuania, Moletai district. A major part of this site is covered by mature oak (Quercus robur) woods with Norway spruce and aspen; in some places by aspen forest. The understorey consists mainly of hazel. Standart "tit boxes" intended for small hole-nesting birds where put up at an average density of 4 nest-boxes per hectare and height of 1.5 -,2.0 m. Internal dimensions of most nest-boxes were 12x12x24 cm, with the diameter of entrance hole 35 mm. They where inspected once a month from April to October, and twice a month in May and September. The number of nest-boxes inspected varied from 115-305 in 1980-1983 and 713-745 in 1984-1990 and 474 in 19911993. The total number of nest-boxes inspected during the investigation period was 7420. In order to investigate the influence of old M. avellanarius nests on occupancy of the nest-boxes in the subsequent spring, in 1983-1987 these nests were left in 898 nest-boxes, while 1461 nest-boxes were emptied. R~~

\

According to our investigations, M. avellanarius will o'h:upy nest-boxes during the first year after they are put up, especially in the autumn. The following spring they occupied ca. 10% and in autumn 30-50% of all nest-boxes. They did not avoid contact with other occupants of artificial nest sites, especially holenesting birds, that occupied on average 36% of all nest-boxes (21-44%) during the investigation period. In Lithuanian mixed forests the main occupants of nest-boxes are Pied flycatchers (Ficedula hypoleuca) and Great tits (Parus major), less frequently Blue tits (Parus caeruleus) and other birds. The greatest competition is observed between M. avellanarius and F. hypoleuca: 9.7% nests of F. hypoleuca were occupied by dormice. Meanwhile dormice occupied only one nest of P. major and none nest of P. caeruleus. In some cases, M. avellanarius occupied nest-boxes with unfinished or already-deserted nests of P. major and used this material for their own nest. Some Crested tit (Parus cristatus), Robin (Erithacus rubecula) and Nuthatch (Sitta europea) nests also were destroyed by dormice (Table 1). Table 1. Occupation of nest-boxes with clutches of hole-nesting birds by M. avellanarius Bird species Number of nest-boxes with clutches total Ficedula hypoleuca Parus major Parus caeruleus Erithacus rubecula Parus cristatus Sitta europea Parus ater lynx torquila Parus montanus Troglodytes troglodytes

1525 953 129 30 7 7 4 3 1 1

Table 2. Influence of M. spring Occupied

inhabited by dormice 148 1

o

1 2 1

o o o o

In most cases M. avellanarius occupied unfinished nests of F. hypoleuca, or nests with incomplete clutches, settling down under these nests without any 290

rebuilding, or reshapiJ with clutches of flyca cases of 148 nests (S (12.2%) only some of narius in nests of F. young successfully. 0 a F. hypoleuca with fi1 Damage done by 11 insignificant. F. hypoJ there are very few fori in place. Besides, the are able to breed agair Long term investi~ selves can suffer frol1 dead animals with del such dormouse was f( leuca. Four more dea~ found in artificial ne Evidently, these anim: that spend nights in record (L 0 h r I 197~ nest of a Tree sparrow After the nesting ~ boxes, but in autumn, 30-50% of nest-boxe investigations revealel major try to avoid nt occupy them only wht are lacking. An increa ved in spring 1984, ~ part of the forest.

Parus major Ficedula hypoleuca Other birds Bombus spp. Dolichovespula saxonica Vespa crabro Overnighting birds *

* use nest-boxes in non-bre

F. hypoleuea almo~ ning old dormouse ne:

1.-

"---

a, Moletai district. A s robur) woods with The understorey conis where put up at an 1.5 - 2.0 m. Internal le diameter' of entranApril to October, and boxes inspected vari90 and 474 in 1991~ investigation period avellanarius nests on 983-1987 these nests Iptied.

lpy nest-boxes during tumn. The following nest-boxes. They did ~ites, especially hole)xes (21-44%) during ~t-boxes are Pied fly~, less frequently Blue

tition is observed bet1ypoleuca were occunest of P. major and ~ occupied nest-boxes used this material for (Erithacus rubecula) dormice (Table 1). YM. avellanarius

'nest-boxes with clutches

.....

rebuilding, or reshaping them into spherical nests. When taking over nest-boxes with clutches of flycatcher eggs present, dormice usually ate the eggs, but in 14 cases of 148 nests (9.5 %) all the eggs remained untouched, and in 18 cases (12.2%) only some of them were eaten. Several times after recording M. avellanarius in nests of F. hypoleuca, the latter continued laying eggs and hatched young successfully. Once a dormouse was found in a nest-box, under the nest of a F. hypoleuca with five young. Damage done by M. avellanarius to breeding of F. hypoleuca in Lithuania is insignificant. F. hypoleuca is the most abundant hole-nesting bird species, and there are very few forests with a high density of M. avellanarius and nest-boxes in place. Besides, the flycatchers whose nests have been occupied by dormice are able to breed again in other nest-boxes. Long term investigations revealed that in some cases M. avellanarius themselves can suffer from hole-nesting birds. Several times nest-boxes contained dead animals with deep wounds on the heads and other parts of the body. One such dormouse was found in summer in a nest-box with a fresh nest of F. hypoleuca. Four more dead dormice with wounds on head, paws and tail have been found in artificial nest sites in autumn (October) and one in spring (April). Evidently, these animals were stiff, and they were pecked to death by P. major, that spend nights in nest-boxes at that time of year. There is a documented record (L 0 h r I 1978) of M. avellanarius being found pecked to death in the nest of a Tree sparrow (Passer montanus). After the nesting season is over it is usual to clean up artificial bird nestboxes, but in autumn M. avellanarius occupy them again. The following spring 30-50% of nest-boxes contain dormouse nests from the previous year. Our investigations revealed that the reaction of hole-nesting birds to this varies. P. major try to avoid nest-boxes containing old nests of dormice (Table 2) and occupy them only when they are placed in very favoured sites or clean nest sites are lacking. An increased occupancy of such nest-boxes by P. major was observed in spring 1984, when many empty boxes had been taken away to another part of the forest. Table 2. Influence of M. avellanarius nests left from previous year on nest-box occupancy in spring Occupied

inhabited by dormice 148 1

o 1

2 1

o o o o its of F. hypoleuca, or ~se

nests without any

_

Parus major Ficedula hypoleuca Other birds Bombus spp. DolichoveslJula saxonica Vespa crabro Overnighting birds *

Nest-boxes with dormouse nests (n=898)

Clean nest-boxes (n=1461) n

%

n

%

312 299 26 38 222 47 416

21.4 20.5 1.8 2.6 15.2 3.2 28.5

19 160 7 290 76 32 71

2.1 17.8 0.8 32.3 8.5 3.6 7.9

chi-squares

P

170.9 2.5 4.0 409.1 22.9 0.2 143.9

< 0.001 >0.05 0.05 < 0.001

* use nest-boxes in non-breeding season (August-April) F. hypoleuea almost equally choose both clean nest-boxes and those containing old dormouse nests (Table 2). Evidently this is connected with differences

291

___________l_L-in habitat requirements: P. major prefer deep nest cavities while F. hypoleuca prefer shallow nest sites. Nest boxes are made shallower by the presence of old dormouse nests. The presence of old dormouse nests in nest-boxes increases the percentage of F. hY/Joleuca nests destroyed (chi-square = 14.0; P < 0.001). In years when old dormouse nests were removed (1980 - 1982 and 1988 - ]993), M. avellanarius destroyed 7.5% of F. hypoleuca nests (72 out of 957). In 1983 - 1987 when these old nests were left alone, more bird nests (76 out of 568) were destroyed by dormice (13.4%). In the last case it is worth noting that 50% of F. hY/Joleuca nests destroyed by dormice were built on old dormouse nests. Artificial nest sites are used by hole-nesting birds not only for nesting but also as overnight roosting places during the whole post-breeding period, August-April (J u s k a i tis 1986). Roosting birds, of which P. major comprised 80%, also preferred to use clean nest-boxes (Table 2). Birds can also stay for a night in nest-boxes containing dormouse nests, but this occurs much less frequently and, judging from the amount of excrements, they stay there for a shorter tiIne than in clean nest-boxes. The presence of the previous. year's M. avellanarius nests in nest-boxes thus appears to have a negative impact on nesting and roosting by hole-nesting birds that avoid occupying such boxes. However, as indicated earlier, in autumn dormice occupy 30-50% of all nest-boxes and as more than half of them stay empty, they can be used by birds both for overnighting and for breeding. F. hypoleuca will occupy nest-boxes containing dormouse nests. On the other hand, nest-boxes containing old M. avellanarius nests actually attract bumble bees (Bombus spp.) which need some nesting material present to encourage them to settle in artificial nest sites. Usually they occupy unfinished or deserted nests of P. major and new nests of M. avellanarius, nests of F. hypoleuca are used much less frequently (in the Table 2 this corresponds to "clean nest-boxes"). Where old M. avellanarius nests were present, bumble bees occupied more than 30% of such nest-boxes. Thus, remnants of M. avellanarius nests provide favourable conditions for these useful insects. BOlnbus hypnorum made up more than half of the bumble bees occupying dormouse nests. Other species found were B. agrorum, B. pratorum, B. lapidarius, B. distinguendus, B. hortorum and B. jonellus. Nests with bumble bee combs can be occupied by M. avellanarius again if they do not yet contain no worker individuals. But if worker bees are already present, dormice do not occupy them, although accidental visits to such nestboxes have been recorded. Wasps (Dolichovespula saxonica) prefer empty, usually new nest-boxes, but quite often also occupy nest sites with dormouse nests present (Table 2). In one case, both M. avellanarius and wasps lived in one nest-box for some time, although nests of wasps and hornets (Vespa crabro) usually scare dormice away. Hornets equally occupy both empty nest-boxes and those containing old dormouse nests (Table 2). In five cases hornets were reported to start building their nests not under the lid of bird nest-boxes, but inside the M. aveiianarius nests. But in these nests there was room only for one hornet comb, so the insects had to leave the nest-box. In some cases, old nests of M. avellanarius were occupied by Bank voles (Clethriononlys glareolus) and Pigmy shrews (Sorex minutus). Several times 292

___

~

new dormouse nests i: which the mammals d~ Nest-boxes placed necked mice (Apodem October they usually ( dance, more than 30~ occupy nest-boxes aln for storage of acorns, c This has lead to an en the winter. Competition betwe nest-boxes, and not fo] three nest-boxes were and A. jlavicollis have placed next to each otl store of A. jlavicollis. M. avellanarius somet There are very few mouse species which; where M. avellanariuj Investigations in Rum~ rable sites, with old 03 lanarius do not occur j favourable places, wh€ boxes can also be occu Such relations are avelianarius populatio 3 ind/ha in autumn). I occur more abundantI nesting birds, insects a Discussion

As mentioned above, I narius and hole-nestin all small hole-nestin! (J e z e r s k a s 1961 ; Moldova - F. hY/Joleu( 1970). In Lithuania, P forests, where M. avel P. caeruleus are much Such difference in probably caused by tv ods. In the middle of ~ are still building their hatching and females boxes. Aggressiveness tion, that tits are abl~

__________

ies while F. hypoleuca by the presence of old

eases the percentage of 01). In years when old 1993), M. avellanarius In 1983 - 1987 when )f 568) were destroyed it 50% of F. hY/Joleuca

~sts.

)t only for nesting but post-breeding period, rhich P. major compriBirds can also stay for ; occurs much less frey stay there for a shor-

lests in nest-boxes thus g by hole-nesting birds earlier, in autumn dorhan half of them stay g and for breeding. F. ests. rlanarius nests actually ting material present to :hey occupy unfinished arius, nests of F. hypocorresponds to "clean ent, bunlble bees occults of M. avellanarius ets. Bombus hypnorum dormouse nests. Other lS, B. distinguendus, B. r. avellanarius again if 'orker bees are already tal visits to such nest-

ly new nest-boxes, but 'esent (Table 2). In one )OX for some time, alty scare dormice away. Ise containing old dord to start building their M. avellanarius nests. .mb, so the insects had ~cupied by Bank voles iinutus). Several times

~~-_I......--.-_--new dormouse nests in nest-boxes were occupied by ants or bumble bees, after which the mammals departed. Nest-boxes placed in mixed and deciduous forests are also used by Yellownecked mice (A/Jodelnus flavicolUs) , but mainly only in autumn. In SeptemberOctober they usually occupy 10-15% of the boxes, and in years with high abundance, more than 30%. Bigger in size and more aggressive, A. flavicollis often occupy nest-boxes already used by dormice, take over their nests, and use them for storage of acorns, as we have already indicated earlier (J u s k a i tis 1993). This has lead to an erroneous view, that Ivl. avellanarius stores acorn supply for the winter. Competition between M. avellanarius and A. flavicollis occurs namely for nest-boxes, and not for territory. This can be proved by the fact that after two or three nest-boxes were put up on some trees, in four cases both M. avellanarius and A. flavicollis have been found at the same time in their nests in nest-boxes placed next to each other. In two cases M. avellanarius was found with an acorn store of A. flavicollis. In spring, when A. flavicollis seldom occur in nest-boxes, M. avellanarius sometimes occupy nests of this lTIOUse. There are very few data on relations between M. avellanarius and other dormouse species which are rare in Lithuania. Until now we know only two sites where M. avellanarius and Edible dormouse (GUs gUs) live in the same forest. Investigations in RUlTIsiskes forest (adjacent to Kaunas city) revealed that favourable sites, with old oaks and many hazels, are occupied by G. gUs, and M. avellanarius do not occur in nest-boxes put up there. They occupy nest-boxes in less favourable places, where oak and hazel are rare or totally absent. The same nestboxes can also be occupied by G. gUs. Such relations are characteristic for Lithuanian mixed forests, in which M. avellanarius population density is comparatively low (ca. 1 ind/ha in spring and 3 ind/ha in autumn). In other parts of the species distribution area, where they occur more abundantly and artificial nest sites contain other species of holenesting birds, insects and small Inalnmal S, these relations can be different. Discussion As mentioned above, most published data describe relations between M. avellanarius and hole-nesting birds. But on sorne issues opinions of authors differ. Of all small hole-nesting birds using nest-boxes, F. hypoleuca suffer the most (Jezerskas 1961; Likhachev 1971; Schulze 1973,1986), and in Moldova - F. hY/Joleuca and the Redstart (Phoenicurus phoenicurus) (L a zan 1970). In Lithuania, Ph. phoenicurus is more abundant, but occur only in pine forests, where M. avellanarius is absent. All authors indicate that P. lnajor and P. caeruleus are much less threatened by M. avellanarius. Such difference in relations between M. avellanarius, tits and flycatchers is probably caused by two things. First, these birds have different breeding periods. In the middle of May, when most dormice occupy nest-boxes, F. hypoleuca are still building their nests and only starting to lay eggs, while tits are already hatching and females sitting on the nests can scare away dormice entering the boxes. Aggressiveness of tits probably also plays some role. The latter presumption, that tits are able to defend their nests, is also suggested by L a zan 293

------------~---....,...---------(1970). F. hypoleuca nesting in nest-boxes also suffer most from interactions with G. glis (Vietinghoff-Riesch 1960; Andresen 1989; our data). L i k hac h e v (1971) expressed doubts about whether M. avellanarius eat bird eggs. The fact that in bird nests occupied by dormice only egg shells without any remnants of yolk and white are found, indicates that eggs in Lithuania are really eaten. This is also stressed by S c h u I z e (1986). However, according to our data, part of clutches or eggs remain untouched. Statements by Polish zoologists (S i d 0 row i c z 1959; Pie low ski & Was i lew ski 1960) that M. avellanarius throw out bird nests from nestboxes, thus destroying bird clutches and young, are also doubtful. We have not registered any such cases. This is also supported by other authors (L 0 zan 1970;Likhachev 1971;Schulze 1973;Airapetjanc 1983). Another unclear and discrep~nt item is whether M. avellanarius eat young and adult birds. This is asserted by L 0 zan (1970) in Moldova, and Gvozdak & Simochko (1977) in Ukraine. Jezerskas (1961) reports that in Lithuania he twice found M. avellanarius eating F. hypoleuca in nest-boxes, but says nothing about eating young birds. During 14 years of investigations we have not registered any of such cases. The same is also noted by L i k hac h e v (1971), who carried out long-term investigations in the Moscow and Tula regions, and by S c h u I z e (1973, 1986) in southern Harz. L i k hac h e v (1971) has often found M. avellanarius under nests of F. hypoleuca with hatching birds in them. Similar cases have been registered in our investigations as well. Air ape tj an c (1983) seems to be correct in saying that in nest-boxes, young or adult birds can be killed by other dormouse species and the nest-box occupied afterwards by the Forest dormouse (Dryomys niteduLa) or M. avellanarius. This seems to be particularly common in Moldova, where three dormouse species, and A. flavicollis live together. In Lithuania, an eaten F. hypoleuca and youngs in flycatchers nest have been found in Rumsiskes forest, where M. avellanarius and G. glis occur. There are some published remarks about the influence on hole nesting birds of the presence of dormouse nests from the previous year nests. J e z e r s k a s (1961) indicates that nest-boxes containing M. avellanarius and A. flavicollis nests or remnants of their stores always remain empty in the future. Our observations show that this is more characteristic for A. flavicollis nests or their stores which can occupy the entire nest-box. Pie low ski & Was i lew ski (1960) indicate birds breed only in empty nest-boxes without dormouse nests. Meanwhile S c h u I z e (1973) ~ays, that in southern Harz, birds occupied both empty nest-boxes and those containing dormouse nests. This tallies with our results. The experiment of leaving old dormouse nests in nest-boxes allowed us to check the statement that removing dormouse nests in spring significantly increases the number of bird nests destroyed in the following year (P i e low ski & Was i lew ski 1960). In Lithuania, we have contrary results: after removing old dormouse nests in spring, the percentage of F. hypoleuca nests occupied by M. avellanarius has decreased twice, compared with years when nests had been left. It should be noted, that these are average figures from long-term investigations at two study sites where the number of flycatchers nets with clutches which 294

were occupied by d< B dormice occupied 1989. Perhaps this ~ only on two years re Published data 01 insects occupying n~ Iiving in nest-boxes M. avellanarius wen (L 0 zan 1970). TI avellanarius ate was cases have not been occupied by bumble Relations betwee been little studied. suggest that low abu connected with dor competition of M. G indicated by Moe k Acknowledgeme

The author is very grat B a lei a u s k a s for Cl for determining bumble t

LITERATURJ

AIRAPETJANC, A.E., mice]. Leningrad, 19 ANDRESEN, D., 198 Beziehungen zwisc und Hohlenbriitem it 5: 118-121, 156-161. GAISLER, J., HOLAS, 1977: Ecology ar Gliridae (Mammalia) Folia Zoo!., 26(3): 2J GVOZDAK, A.A. & ~ 1977: Sonya oreshni avellanarius L.) - ko lognezdnykh ptic I (Muscardinus avellar tor for small hole-n zoolog ii, 3: 88-89 (in JEZERSKAS, L.I., 196] teli duplyanok v le5 ikh vliyaniye na ptic Ekologiya i mign [Strange occupants 0 of Lithuanian SSR hole-nesting birds]. ] gy and migrations Russian).

lost from interactions dresen 1989; our

~r

M. avellanarius eat

e only egg shells wit-

that eggs in Lithuania

186). However, accorl. 59; Pie low ski &

bird nests from nestloubtful. We have not ~er authors (L 0 zan tj an c 1983). vellanarius eat young 0) in Moldova, and ez e r s k a s ( 1961 ) ~ating F. hypoleuca in ing 14 years of invesiame is also noted by nvestigations in the 186) in southern Harz. nder nests of F. hypoleen registered in our ) be correct in saying ther dormouse species luse (Dryomys nitedu:ommon in Moldova, ~ther. In Lithuania, an n found in Rumsiskes on hole nesting birds ~ nests. J e z e r s k a s ~ius and A. flavicollis

the future. Our obseJllis nests or their stoi & Wasilewski :hout dormouse nests. ~, birds occupied both This tallies with our t-boxes allowed us to g significantly increa:ar(Pielowski & esults: after removing r nests occupied by M. 1 nests had been left. long-term investigatis with clutches which

were occupied by dormice varied greatly in different years. For instance, at site B dormice occupied 14 of 107 flycatcher nests in 1988, and only two of 84 in 1989. Perhaps this explains the results of Polish zoologists, which were based only on two years research. Published data on relations between M. avellanarius and other mammals and insects occupying nest-boxes are few. In Moldova, some G. gUs or A. flavicollis living in nest-boxes were observed to eat nestlings of M. avellanarius. Nestling M. avellanarius were also often killed by ants and hornets occupying nest-boxes (L 0 zan 1970). The opposite fact has been registered in Germany, when M. avellanarius ate wasp combs in a nest-box (M 0 c k e I 1988). In Lithuania such cases have not been observed. In Germany, old M. avellanarius nests were also occupied by bumble bees (M 0 c k e I 1988). Relations between different dormice species, where they live together, have been little studied. Only the Czech mammalogists (G a i s I e r et al. 1977) suggest that low abundance of M. avellanarius in nest-boxes at one study site is connected with dominance by G. glis, a more aggressive species. Possible competition of M. avellanarius and Garden dormouse (Eliomys quercinus) is indicated by M 0 c k e I (1988). All this requires further investigation. Acknowledgements The author is very grateful to Prof. Dr. P.A. M 0 r r is, Dr. B. K r y stu f e k and Dr. L. B a lei a u s k a s for critical reading of the manuscript and for help, to V. M 0 n s e vic ius for determining bumble bee species, and to Dr. E. Bud r y s for determining wasp species.

LITERATURE AIRAPETJANC, A.E., 1983: Soni [The dormice]. Leningrad, 192 PP: (in Russian). ANDRESEN, D., 1989: lTber allgemeine Beziehungen zwischen SiebenschHifern und Hohlenbrlitern in Nistkasten. Falke, 45.' 118-121, 156-161. GAISLER, J., HOLAS, V., HOMOLKA, M., 1977: Ecology and reproduction of Gliridae (Mammalia) in Northern Moravia. Folia Zool., 26(3): 213-228. GVOZDAK, A.A. & SIMOCHKO, M.D., 1977: Sonya oreshnikovaya (Muscardinus avellanarius L.) - konkurent melkikh duplognezdnykh ptic [Common dormouse (Muscardinus avellanarius L.) - a competitor for small hole-nesting birds]. Vestnik zoologii, 3.' 88-89 (in Russian). JEZERSKAS, L.I., 1961: Postoronniye obitateli duplyanok v lesakh Litovskoj SSR i ikh vliyaniye na ptic-duplognezdnikov. In: Ekologiya i migracii ptic Pribaltiki. [Strange occupants of nest-boxes in forests of Lithuanian SSR and their impact on hole-nesting birds]. In: Baltic birds ecology and migrations. Riga, 123-128 (in Russian).

JUSKAITIS, R., 1986: Nochevka ptic v iskusstvennykh gnezdovyakh v poslegnezdoYoj period. In: Ekologiya ptic Litovskoj SSR. [Overnighting of birds in artificial nest sites during post-breeding period.]. In: Bird ecology in Lithuanian SSR. Vilnius, 3: 150159 (in Russian). JUSKAITIS, R., 1993: K voprosu 0 pitanii (Muscardinus avellanarius L.) YLitve. (On Common dormouse (Muscardinus avellanarius L.) feeding in Lithuania). Ekologija, 2: 20-24 (in Russian, with a summary in English). LIKHACHEV, G.H., 1971: K biologii oreshnikovoj sonL In: Trudy Prioksko-Terrasnogo gosudarstvennogo zapovednika. [On Common dormouse biology]. In: Works of Prioksko- Terrasnnij state reserve . .. Moskow, 5: 160-175 (in Russian). LOHRL, H., 1960: Saugetiere als Nisthohlenbewohner in Stidwestdeutschland mit Bemerkungen tiber ihre .. Biologie. Z. Siiugetierkd., 25(1-2): 66-73. LOHRL, H., 1978: Hohlenkonkurenz und Herbst-Nestbau beim Feldsperling (Passer montanus). Vogelwelt, 99(4): 121-131.

295

LOZAN, M.N., 1970: Mlekopitayushchiye Moldavii. [Rodents of Moldavia]. .. Kishinev, 168 pp. (in Russian). MOCKEL, R., 19.~8: Zur Verbreitung, Haufigkeit und Okologie der Haselmaus (NIuscardinus avellanarius) im Westerzgebirge. Saugetierkd. In[., 2(12): 569-588. PIELOWSKI, Z. & WASILEWSKI, A., 1960: Haselmause in Vo~elnistkasten. Z. Saugetierkd., 25(1-2): /4-80. SCHULZE, W., 1973: Untersuchungen zur Biologie der Haselmaus (Muscardinus avellanarius L.) im SUdharz. Arch. Naturschutz u. Landschaftsforsch., 13(2): 107-121. SCHULZE, W., 1986: Zum Vorkommen und zur Biologie von Haselmaus (Muscardinus

avellanarius L.) und Siebenschlafer (Glis glis L.) in Vogelkasten im Stidharz der DDR. Saugetierkd. 1nf" ~(l 0): 341-348. SIDOROWICZ, J., 1959: Uber Morphologie und Biologie der Haselmaus (Muscardinus avellanarius L.) in Polen. Acta theriot., (5): 75-91. SHTRAUS, U., 1959: Oreshnikovaya sonya (Muscardinus avellanarius L.) v Latvijskoj SSR. In: Fauna Latvijskoj SSR i sopredelnykh territorij. [Common dormouse (Muscardinus avellanarius L.) in Latvian SSR]. In: Fauna of Latvian SSR and adjacent territories. Riga, 2: 233-236 (in Russian). VIETINGHOFF-RIESCH, A.v., 1960: Der Siebenschlafer (Glis glis L.). lena, 196 pp.

FOLIA ZOOLOGICA - 44(

RELATIONS B: (MUSCARDINl OCCUPANTS ( RilTIvydas JU5KAITIS

Institute of Ecology,

Ac~

Abstract

Relations between Coml boxes are cOlnpetitive. ( cher (Ficedula hypoleu 111ajor) and Blue tit (P. c affected by dormice. Ne avellanarius. In autumn (Apodefnus flavicollis). l on roosting and breedin occupation by bumble b(

Introduction

Many published rep rius L.) occupy artif small hole-nesting t 1959; Straus J e z e r s k a s 19( S c h u I z e 1973, 1993 and others). H investigated. In fact there are] mammal species or also been paid to t boxes 011 hole-nestiJ

Study Area, Mater

Author's address: Dr. Rimvydas JUSKAITIS,

Institute ofEcology, AcadenlY of Sciences ofLithuania, Akadelnijos 2, 2600 Vilnius, Lithuania

296

A comprehensive iI occupants of artifici 1) site A - studif middle-aged, mixed species are birch (1 (Alnus glutinosa), i excelsior). The und horn (Frangula alnz