Contrasting molecular and morphological evidence for the ...

A peer-reviewed version of this preprint was published in PeerJ on 10 January 2017. View the peer-reviewed version (peerj.com/articles/2850), which is the preferred citable publication unless you specifically need to cite this preprint. Clark WS, Galen SC, Hull JM, Mayo MA, Witt CC. (2017) Contrasting molecular and morphological evidence for the identification of an anomalous Buteo: a cautionary tale for hybrid diagnosis. PeerJ 5:e2850 https://doi.org/10.7717/peerj.2850

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Contrasting molecular and morphological evidence for the identification of an anomalous

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Buteo: a cautionary tale for hybrid diagnosis

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William S. Clark, ([email protected]), 2301 South Whitehouse Circle, Harlingen, TX

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78550

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Spencer C. Galen, Sackler Institute for Comparative Genomics, American Museum of Natural

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History, New York, New York, 10024

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Joshua M. Hull, Department of Animal Science, University of California, Davis, California,

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95616

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Megan A. Mayo, Department of Animal Science, University of California, Davis, California,

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95616

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Andrew Engilis, Jr., Museum of Wildlife and Fish Biology, University of California, Davis,

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California, 95616

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Christopher C. Witt, Department of Biology and Museum of Southwestern Biology, University

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of New Mexico, Albuquerque, New Mexico, 87131, USA

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PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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Abstract.

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An adult Buteo was found dead as a road-kill south of Sacramento, California, and was thought

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to represent the first state record of the eastern Red-shouldered Hawk (B. lineatus lineatus; Pyle

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et al. 2004). It is now a specimen in the Museum of Wildlife and Fish Biology (WFB 4816) at

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the U. of California, Davis. We examined this specimen and found that many of its plumage

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characters differed from all other adult Red-shouldered Hawks examined, including nominate

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adults. Plumage markings and measurements were intermediate between Red-tailed Hawk

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(Buteo jamaicensis, ssp calurus) and Red-shouldered Hawk (ssp elegans), leading us to

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hypothesize that the bird was a hybrid. However, mtDNA sequences and nuDNA microsatellites

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proved definitively that the bird was a Red-shouldered Hawk, most likely of eastern origin. This

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case illustrates that apparent hybrids or apparent vagrants could be individuals with anomalous

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phenotypes caused by rare genetic variation or novel epigenetic effects.

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Keywords: Unusual plumage, DNA ,specimen, hybrid, morphology, phenology

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2 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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INTRODUCTION Hybridization often occurs between sympatric populations of closely related species, and it is a

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process that can have important evolutionary consequences (Seehausen, 2004; Rheindt and

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Edwards 2011). Hybridization can accelerate or slow speciation (Abbott et al., 2013), can rescue

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inbred lineages (Frankham, 2015), and can lead to extinction (Allendorf et al., 2001). Often the

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youngest, or most recently radiated species experience hybridization (Mallet, 2005). Raptors of

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the genus Buteo are part of a rapid, recent radiation in which many species overlap in their

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distribution (Riesing et al. 2003). Numerous cases of hybridization among Buteo species have

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come to light relatively recently (e.g., Dudás et al. 1999, Pfander and Schmigalew 2001, Clark

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and Witt 2006, Hull et al. 2007a, Corso and Gildi 2007, Gjershaug 2010), often resulting in

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individuals with intermediate characteristics.

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Presently, we examine a specimen that appears intermediate in physical characteristics between

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Red-tailed Hawk (B. jamaicensis) and Red-shouldered Hawk (B. lineatus), a hybrid combination

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not previously noted in the peer-reviewed literature. This specimen provides an opportunity to

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more closely examine hybridization using morphological and genetic data of two mobile, wide-

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ranging species in North America.. The specimen had been described previously as a vagrant

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eastern Red-shouldered Hawk (B. l. lineatus) in California (Pyle et al. 2004); however, the

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possibility of hybrid status was not examined quantitatively, and no molecular data were used.

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We re-evaluated the findings of Pyle et al. (2004) for two reasons: (1) Many of the plumage

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markings and morphological characteristics appear to be intermediate between Red-shouldered

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and Red-tailed and (2) several recent records of hybrids between Buteo species suggest that


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hybridization is occurring regularly in the genus; therefore, understanding the circumstances

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where hybridization occurs can illuminate the ongoing evolutionary processes within this genus.

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METHODS

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We examined the plumage patterns and colors of 76 specimens of adult eastern and western

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Red-shouldered Hawks in nine museums (Appendix 1). We scored the following characters:

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malar and throat color, color and markings of the remiges and upper tail coverts, color of the

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lesser upper wing coverts, and the number of white tail bands. We compared these characters to

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those of the putative hybrid (WFB 4816).

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We measured the wing chord, exposed culmen length, hallux chord, tarsus length, and standard

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tail length of adult specimens of three taxa: western Red-tailed Hawks (B. j. calurus) from

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California (n=23), Red-shouldered Hawks from California (B. l. elegans; N=33), and eastern

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North America (B. l. lineatus; N=46), respectively. We centered and scaled the variables prior to

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conducting a principle components analysis (PCA) using the command prcomp in the stats

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package in R (http://www.r-project.org/). Individual measurements are shown in Appendix 1.

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We extracted DNA from a toepad sample of WFB4816 using a modified Qiagen DNeasy kit

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protocol by adding 30 ul 100mg/ml DTT (dithiothreitol) to the proteinase K digestion and eluting

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the sample in 50 μl instead of the standard 200 μl. A negative control was included during the

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extraction process. We designed primers that amplify a 191 bp fragment of the mitochondrial

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gene ND2 (buteoND2F: CTGAACAAAATCCCCCACAC; buteoND2R:

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CGAGGCGGAGGTAGAAGAAT), and PCR amplified this fragment using 45 cycles of 94° for

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30 s, 50° annealing for 30 s, and 72° extension for 1 minute. We Sanger-sequenced this PCR

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product on an ABI 3130 machine. 4 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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Extracted DNA was amplified and genotyped at 18 microsatellite loci (A110, A302, A303,

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B111a, B220, B221, D107, D122, D123, D127, D207, D220, D223, D234, D235, D310, D327,

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D330) in six multiplex PCRs following the conditions described in Hull et al. (2007b). PCR

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products were separated with a 3730 DNA Analyzer (Applied Biosystems Inc.), and then scored

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using STRAND version 2.3.89 (Toonen and Hughes 2001). For comparison, we obtained

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genotypes from these loci for eastern and western Red-shouldered Hawks and Red-tailed Hawks

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from previous population genetic studies of these species (Hull et al. 2008a, Hull et al. 2008b).

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To visualize the genetic relationship of the possible hybrid specimen with eastern Red-

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shouldered Hawks and Red-tailed Hawks, we performed a factorial correspondence analysis

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(FCA) (GENETIX 4.05.2; Belkhir et al. 2000). The FCA clustered genotypic groups based on

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microsatellite allele frequencies using the ordination of samples along varying factorial axes to

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visualize genetic similarity of the samples in two-dimensional space. In this analysis, a hybrid

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individual would be indicated by its intermediate location in the FCA between the genotypic

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groups for Red-shouldered and Red-tailed Hawks.

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We also investigated the ancestry of the museum specimen through assignment tests using a

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Bayesian clustering algorithm (STRUCTURE version 2.1; Pritchard et al. 2000). This analysis

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was first performed comparing the museum specimen with a combined eastern and western

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sample of Red-shouldered Hawks and a sample of Red-tailed Hawks. Subsequently, we

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performed a second analysis comparing the museum specimen to separate eastern Red-

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shouldered hawks and western Red-shouldered Hawks. No Red-tailed Hawks were included in

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the second test. For both analyses we used the population admixture model with a population 5 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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prior corresponding to either species (test 1) or sampling location (test 2) and assumed that allele

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frequencies were correlated among populations. We ran the simulation with a 10,000 iteration

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burn-in and a run length of 100,000 iterations. We limited the analysis to K = 2 (where K is the

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number of populations) because of our prior knowledge of the species and geographic origin of

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the samples. We then generated Q plots to visualize proportion of ancestry for the museum

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specimen in relationship to possible populations of origin.

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RESULTS

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The putative hybrid specimen (WFB 4816) differed in plumage from all adult Red-shouldered

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Hawks, and, specifically, from adult eastern ones. Plumage differences are summarized in Table

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1. Figure 1A shows that the putative hybrid has a dark throat, as compared to a typical adult Red-

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shouldered, all of which have a pale throat and dark malar stripes. The putative hybrid also

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shows dark brown barring on the belly, a feature not shown on any adult Red-shouldered Hawk.

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Figure 1B shows that the putative hybrid has six or seven narrower white tail bands, compared to

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adult Red-shouldered Hawks, which usually have three or four wider bands (but a few had five

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bands). The tail bands and upper tail coverts on the putative hybrid show rufous tinges that are

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not seen on any adult Red-shouldered Hawk. Figure 1C shows the lack of white spotting on the

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uppersides of the remiges of the putative hybrid, whereas adult Red-shouldered Hawks always

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show numerous white spots. The lack of rufous on the lesser upper wing coverts of the putative

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hybrid is another characteristic that is inconsistent with Red-shouldered Hawk (shoulder; Fig 3).

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The largest hallux measurement on any adult eastern Red-shouldered Hawk was 23.9 mm

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(range 18.4-23.9 mm, n=46), which was smaller than that of the putative hybrid specimen, 25.1

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mm. 6 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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The PCA analysis of morphological measurements showed that eastern and western Red-

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shouldered Hawks each formed distinct clusters, but with some overlap. Red-tailed Hawks

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formed a separate, discrete cluster. The putative hybrid specimen fell outside of the ranges of

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measurement of any of the three taxa in our PCA (Figure 2). Although it was closest to eastern

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Red-shouldered Hawks, it was also outside of the range of variation observed in other eastern

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Red-shouldered Hawks, and it was in between the centroids of California Red-shouldered Hawks

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and California Red-tailed Hawks on the PC1 axis, which explained 80.5% of the variance.

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We successfully sequenced the complete 191 bp ND2 fragment of specimen WFB4816

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(GenBank accession number: KX154215). An NCBI BLAST search revealed that the sequence

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has 100% sequence identity to Red-shouldered Hawk (EU583276.1) and 99% similarity to two

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additional Red-shouldered Hawk sequences (GQ264875.1, GQ264874.1). All Red-tailed Hawk

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ND2 sequences on GenBank differ from WFB4816 by at least 7 substitutions in the sequenced

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fragment (96% similarity).

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Mitochondrial DNA (mtDNA) showed that the putative hybrid matches Red-shouldered Hawk,

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providing decisive evidence that its mother was a Red-shouldered Hawk. However, the mtDNA

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haplotype that we recovered was shared between eastern and western North American

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populations of Red-shouldered Hawk.

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The factorial correspondence analysis showed distinct clusters of individuals corresponding to

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Red-tailed Hawks and Red-shouldered hawks in the comparison between these species (Fig. 3A)

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with WFB 4816 grouping within the Red-shouldered hawk cluster. In the second factorial

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correspondence analysis, we found two clusters corresponding to eastern and western Red-


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shouldered Hawks with an area of overlap between the two (Fig. 3B). In this second analysis

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WFB 4816 grouped within the eastern Red-shouldered Hawk cluster.

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The Bayesian clustering analysis revealed a similar pattern to that seen in the factorial

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correspondence analysis. In the first analysis when K was set to 2 we found two distinct groups

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with very high proportions of ancestry corresponding to either Red-tailed Hawks or Red-

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shouldered Hawks (Fig. 4A). In this analysis, WFB 4816 showed ancestry solely from Red-

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shouldered Hawks. In the second analysis, K = 2 corresponded to groupings of eastern and

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western Red-shouldered Hawks with low levels of admixture between the two groups (Fig. 4B).

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In this case, WFB 4816 showed a high proportion of ancestry derived from eastern Red-

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shouldered Hawks.

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DISCUSSION

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The mtDNA and nuDNA data that we analyzed definitively identified this specimen as a Red-

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shouldered Hawk. The microsatellite data suggests that it was most likely of eastern origin,

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consistent with the original conclusion of Pyle et al. (2004). Records of eastern Red-shouldered

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Hawks outside of their eastern range, though rare, have been recorded previously, including a

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specimen that was salvaged in Albuquerque, New Mexico, in 1991 (MSB:Bird:8174).

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The morphometric measurements and plumage comparison that we present here appeared to

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comprise compelling evidence that WFB 4816 represents a hybrid between a Red-tailed Hawk

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and Red-shouldered Hawk. F1 hybrids are typically intermediate in size and plumage between

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the parental species (Rohwer 1994). The fact that this adult was larger than any of 46 eastern

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Red-shouldered Hawks that we measured appears to conflict with the conclusion of Pyle et al.

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(2004) that the specimen represented an eastern vagrant. Furthermore, its combination of 8 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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plumage markings is unknown from any other specimen we examined and resembles an

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amalgamation of characteristics from both species.

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This case illustrates that anomalous plumage markings or size measurements that are

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intermediate between two species do not always result from hybridization. Although we cannot

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rule out that Red-tailed Hawk alleles may have contributed to the intermediate phenotype of

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WFB 4816, the microsatellite data do not show any evidence of mixed ancestry. Pyle et al.

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(2004) described this specimen as an eastern Red-shouldered Hawk and reported it as the first

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definitive record of an eastern Red-shouldered Hawk in California, our results support this

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conclusion. We conclude the anomalous phenotype of this bird was most likely the result of a

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rare genetic mutation, congenital abnormality, or unusual epigenetic interaction. Future

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diagnoses of hybrid or subspecies status should consider these possibilities.

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This specimen is not the only suspected hybrid between Red-tailed Hawks and Red-shouldered

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Hawks. Photographs of a similar adult from Connecticut have been posted on-line (Connecticut

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Audubon Society blog, January 6, 2011). Additional Buteo hybrids include those reported by

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Clark and Witt (2006), a hybrid specimen of Rough-legged (B. lagopus) x Swainson’s (B.

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swainsoni) Hawks, and Hull et al. (2007) on several cases of hybrids between Red-tailed and

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Swainson’s Hawks. Both of these papers also used DNA, plumages, and morphometrics to

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determine hybridization. We have examined unpublished photographs of two adults that show

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characters of two species, one of Red-tailed and Ferruginous (B. regalis) Hawks and the other of

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Red-tailed and Rough-legged Hawks. Four further hybridizations between two species of Buteo

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have been reported from Eurasia—Rough-legged x Common (B. buteo) Buzzards (Gjershaug et

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al. 2010), Long-legged x Common Buzzards (Dudás et al. 1999, Corso 2007) , and Long-legged

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x Upland (B. hemilasius) Buzzards (Pfander and Schmigalew. 2001). Clark et al. (2005) report 9 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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on four instances of hybrids, three between species in Buteo, but also an intergeneric case of

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Swainson’s Hawk male and Red-backed Buzzard (Geranoaetus polyosoma) in Colorado. The

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provenance of the latter was never determined (Allen 1998). The most phylogenetically distant

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hybrid pairing involving a Buteo is that reported by Corso and Gildi (1998) from Italy of a

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Common Buzzard mated with a Black Kite (Milvus migrans) that produced two fledglings.

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Although hybridization occurs regularly but at low levels within Buteo, there appears to be no

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evidence of extensive introgression that may destabilize species boundaries. However, low levels

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of hybridization may result in reciprocal exchange of novel genes between otherwise stable

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species if resultant offspring can successfully backcross. In such cases, novel genes may cause

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evolutionary change if the novel genes result a selective advantage to the recipient species.

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Continued examination of atypical museum specimens in combination with genomic analyses

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may provide an opportunity to test whether genetic introgression has resulted from the rare

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occasions of hybridization.

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ACKNOWLEDGEMENTS

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We would like to thank the American Museum of Natural History, the Museum of Southwestern

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Biology of the University of New Mexico, the Western Foundation of Vertebrate Zoology, and

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the Museum of Wildlife and Fish Biology of the University of California-Davis for making their

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collections open to our study. Funding was provided in part by NSF DEB-1146491 and NSF 205

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GRF 1148897.

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LITERATURE CITED


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ABBOTT, R., ALBACH, D., ANSELL, S., ARNTZEN, J.W., BAIRD, S.J.E., BIERNE, N.,

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BOUGHMAN, J., BRELSFORD, A., BUERKLE, C.A., BUGGS, R. and BUTLIN, R.K.,

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ALLEN, S. 1988. Some thoughts on the identification of Gunnison’s Red-backed Hawk (Buteo

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polyosoma) and why it’s not a natural vagrant. Journal of the Colorado Field

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Ornithologists 22:9–14.

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ALLENDORF, F. W., LEARY, R. F., SPRUELL, P., and WENBURG, J. K. 2001. The

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problems with hybrids: setting conservation guidelines. Trends in Ecology and Evolution

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16: 613-622.

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BELKHIR, K., BORSA, P., CHIKHI, L., RAUFASTE, N., and BONHOMME, F. 1996–2001.

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GENETIX 4.02, logiciel sous Windows TM pour la génétique des populations,

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Laboratoire Génome, Populations, Interactions; CNRS UMR 5000; Université

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.CLARK, W. S., M. REID, and B. K. WHEELER. 2005. Four cases of hybridization in North American Buteos. Birding 37:256-263.

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CLARK, W. S., and C. C. WITT. 2006. First known specimen of a hybrid Buteo: Swainson’s

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Hawk (Buteo swainsoni) x Rough-legged Hawk (B. lagopus) from Louisiana. Wilson

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CORSO, A. and GILDI, R. 1998. Hybrids between Black Kite and Common Buzzard in Italy in 1996. Dutch Birding 20: 226–233


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DUDÁS, M., J. TAR, and I. TÓTH. 1999. [Natural hybridization of Long-legged Buzzard

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(Buteo rufinus) and Common Buzzard (B. buteo) in the Hortobagy National Park.] In

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Hungarian. Ölyvek,, keveredése”. Temészet, 5-6:8-10.

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FRANKHAM, R. 2015. Genetic rescue of small inbred populations: a meta-analysis reveals

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large and consistent benefits of gene flow. Molecular Ecology 24: 2610-2618.

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GJERSHAUG, J. O., O. A. FORSET, K. WOLDVIK and Y. ESPMARK. 2010. Hybridisation

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between Common Buzzard Buteo buteo and Rough-legged Buzzard B. lagopus in

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Norway. Bull. B.O.C. 2006 126(1):73-80.

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HULL, J. M., W. SAVAGE, J. P. SMITH, N. MURPHY, L. CULLEN, A. C. HUTCHINS, and

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H. B. ERNEST. 2007. Hybridization among Buteos: Swainson’s Hawks (Buteo

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swainsoni) X Red-tailed Hawks (Buteo Jamaicensis). The Wilson Journal of Ornithology

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119(4):579–584.

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MALLET, J. 2005. Hybridization as an invasion of the genome. Trends in Ecology and Evolution 20: 229-237. PFANDER, P. and S. SCHMIGALEW. 2001. [Extensive hybridization of Long-legged Buzzard

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Buteo rufinus and Upland Buzzard B. hemilasius.] In German. Ornithologische

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Mitteilung 53:344-349.

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PRITCHARD J,. K, STEPHENS, and M, DONNELLY. 2000. Inference of population structure using multilocus genotype data. Genetics, 155, 945-959. .PYLE, P., A. ENGILIS, JR., and T. G. MOORE. 2004. A specimen of the nominate subspecies of the Red-shouldered Hawk from California. Western Birds 35:100-104. 12 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2039v1 | CC-BY 4.0 Open Access | rec: 10 May 2016, publ: 10 May 2016

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RHEINDT, F. E., and S. V. EDWARDS. 2011. Genetic introgression: an integral but neglected component of speciation in birds. Auk 128:620-632. RIESING, J. M., L. KRUCKENHAUSER, A. GAMAUF, AND E. HARING. 2003. Molecular

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ROHWER, S. 1994. Two new hybrid Dendroica warblers and new methodology for inferring parental species. Auk 111:441–449. SEEHAUSEN, O. 2004. Hybridization and adaptive radiation. Trends in Ecology and Evolution 19: 198-207. TOONEN RJ, and S. HUGHS. 2006. Increased throughput for fragment analysis on an ABI

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Figure 1. Comparison of adult Eastern Red-shouldered Hawk (r) with WFB 4816 (l). A. Undersides. Note dark throat and dark belly markings of WFB 4816. B. Upper tails. Note six tail bands of WFB 4816. C. Upper wings. Note lack of white spotting on upper wings of WFB 4816.

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PC2 (9.7% explained var.)

B. j. calurus

B. l. elegans

B. lineatus, eastern subspp.

Putative hybrid, WFB 4816

1

0

−1

−2

0

2

4

PC1 (80.5% explained var.)

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Figure 2. Plot of the first two principle components based on the PCA of five measurements from 103 adult eastern Red-shouldered Hawks (B. lineatus subspp.), California Red-shouldered Hawks (B. l. elegans), and western Red-tailed Hawks (B. j. calurus) representing both sexes showing that the putative hybrid is intermediate in its morphometric measurements between Redshouldered Hawk and Red-tailed Hawk.

283


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Figure 3. Results of the principle components analysis of 18 microsatellite loci for WFB 4816 (yellow circles) compared to (A) eastern and western Red-shouldered Hawks, and (B) eastern and western Red-shouldered Hawks and western Red-tailed Hawks


Figure 4. Results of Bayesian clustering analysis of 18 microsatellite loci for (A) Red-tailed Hawks, eastern and western Redshouldered Hawks, and WFB 4816 and (B) eastern and western Red-shouldered Hawks and WFB 4816. Figure 4A compares the proportion of ancestry for each individual for K=2 with one population composed of Red-shouldered Hawks (indicated in green) and on population of Red-tailed Hawks (indicated in red). Figure 4B compares the proportion of ancestry for each individual for K=2 with one population composed of eastern Red-shouldered Hawks (indicated in green) and one population composed of western Red-shouldered Hawks (indicated in red); note that one of the Red-shouldered Hawks sampled in California appears to have mixed eastern and western ancestry. WFB 4816 is at the left of each figure and outlined in a dashed line. In figure 4A WFB 4816 shows a high proportion of Red-shouldered Hawk ancestry and in Figure 4B WFB 4816 ii further indicated as having primarily eastern Red-shouldered Hawk ancestry.


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Table 1. Comparison of plumage characters and hallux with putative hybrid specimen with specimens of adult eastern and western Red-shouldered Hawks and western Red-tailed Hawks.

Character

WFB 4816

Adult East & West RS’s

Adult West RT’s

Malar & throat

Uniformly dark

Darker malars; paler throat, often with dark streaks

Dark or dark with pale streaks

1

Belly barring

Dark brown, with short dark streaks

Rufous

Dark brown with short dark streaks

1

Uppersides of remiges Gray barring, no white on primaries

Gray barring with white spots across primaries

Dark brown. No white on primaries

3

Remige tips

Narrow gray tips

Wide white tips

Dark tips

3

Lesser upper wing coverts

Dark brown with no rufous

Show rufous ‘shoulders’

Dark brown

3

Upper tail coverts

Dark brown with rufous and white barring

Dark brown with white barring only

Rufous with dark brown barring

3

No. of tail bands

6 (or 7)

4 or fewer (five had 5 bands)

No pale bands

2

Tail band color

White with rufous tint

White only, no rufous

No pale bands

2

__________________________________________________________________________

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Figure no.

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Appendix 1. Morphometric data used in the PCA. Museum acronyms in specimen identifiers include AMNH (American Museum of Natural History), MSB (Museum of Southwestern Biology of the University of New Mexico), WFVZ (Western Foundation of Vertebrate Zoology), and WFB (Museum of Wildlife and Fish Biology of the University of California-Davis). Specimen WFVZ:Bird:20607 WFVZ:Bird:32972 WFVZ:Bird:36209 WFVZ:Bird:39 WFVZ:Bird:53726 WFVZ:Bird:53990 WFVZ:Bird:54010 WFVZ:Bird:57218 WFVZ:Bird:5846 WFVZ:Bird:6000 WFVZ:Bird:6337 WFVZ:Bird:705 WFVZ:Bird:20579 WFVZ:Bird:32565 WFVZ:Bird:32936 WFVZ:Bird:37106 WFVZ:Bird:43362 WFVZ:Bird:45305 WFVZ:Bird:53764 WFVZ:Bird:56775 WFVZ:Bird:6517 WFVZ:Bird:6642 WFVZ:Bird:6711 WFVZ:Bird:154 WFVZ:Bird:31 WFVZ:Bird:44650

Taxon B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. j. calurus B. l. elegans B. l. elegans B. l. elegans

Sex f f f f f f f f f f f f m m m m m m m m m m m f f f

Wing chord (mm) 408 419 400 394 407 419 428 403 404 419 401 417 377 387 391 365 385 396 397 373 369 394 385 317 314 307

Culmen (mm) 27 27.5 26.9 25.7 27.8 23.6 24.5 25.7 26.5 26.3 24.2 26.7 23.6 24.2 24.2 25.5 24.9 24.2 26.3 24.2 23.3 24.3 23.9 20.4 20.9 21.2

Tarsus (mm) 89.5 97.5 99.6 90.9 96.2 101.5 108.6 98.5 90.2 90.5 96.8 91.4 95.5 95.8 95.2 92.8 90.6 91.8 95.3 93.3 90.3 95.1 94.3 84.2 81 84

Hallux (mm) 27.4 30.4 29.7 28.9 28.8 27.7 29.8 28.4 27.5 29.4 28.5 30.2 28.3 27.6 27.2 26.6 27.4 27.3 29.8 28.8 27.3 27.4 28.3 22.8 22.7 20.6

Tail (mm) 206 229 217 221 222 225 230 220 217 221 223 218 215 203 217 199 202 198 196 194 204 212 202 193 199 191

State or Province CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA

19


Unusual Cal RS WFVZ:Bird:44651 WFVZ:Bird:52711 WFVZ:Bird:53466 WFVZ:Bird:53525 WFVZ:Bird:53751 WFVZ:Bird:53752 WFVZ:Bird:54013 WFVZ:Bird:56778 WFVZ:Bird:56964 WFVZ:Bird:5985 WFVZ:Bird:6156 WFVZ:Bird:6274 WFVZ:Bird:710 MSB:Bird:25344 WFVZ:Bird:29384 WFVZ:Bird:32971 WFVZ:Bird:3949 WFVZ:Bird:42145 WFVZ:Bird:43374 WFVZ:Bird:45273 WFVZ:Bird:5038 WFVZ:Bird:52712 WFVZ:Bird:53484 WFVZ:Bird:56777 WFVZ:Bird:5835 WFVZ:Bird:5845 WFVZ:Bird:5921 WFVZ:Bird:5933 WFVZ:Bird:6241 WFVZ:Bird:6519 AMNH:Bird:168613 AMNH:Bird:352521 AMNH:Bird:352553 AMNH:Bird:352559

B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. l. elegans B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern)

f f f f f f f f f f f f f m m m m m m m m m m m m m m m m m f f f f

320 318 307 296 289 310 321 300 311 312 314 310 301 293 291 300 302 283 297 278 292 296 292 289 287 292 286 278 302 280 352 354 355 347

22.4 21 20.7 21.7 20.1 20.7 21.3 22.2 20 23.2 21.3 25 22.6 19.56 20.2 19.7 20.3 20 17.8 20.8 20.6 19.2 18.2 20.5 19 19.4 19.5 20.8 18.9 18.5 24.42 24.44 23.95 22.71

86.1 84.2 85.8 84.3 77.5 81.6 85.4 86.8 79 82 80.7 85.4 82.3 78.53 78.6 85 84.8 82.6 77.2 82.3 78.5 79.7 76.4 80.5 76.5 81.1 77.3 83 81.5 78.7 80.85 79.23 81.13 80.8

26.2 22.7 20.7 22.3 20.5 22.6 21.7 22.5 21.4 23 22.7 23 22.2 21.17 22.8 18.2 23.1 19.9 19 20.2 18.8 21.5 17.8 20.2 19.2 20.3 21.3 21.4 20.1 20.2 22.92 23.86 23.18 22.81

194 189 193 190 182 192 209 182 192 202 196 203 186 208 180 173 191 172 176 177 180 181 173 187 173 172 184 168 181 185 211 204.13 208.8 199.56

CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA CA NY IA NH ON

20


Unusual Cal RS AMNH:Bird:470684 AMNH:Bird:69780 AMNH:Bird:69781 AMNH:Bird:750225 AMNH:Bird:832602 AMNH:Bird:96626 MSB:Bird:24325 MSB:Bird:24885 MSB:Bird:4291 WFVZ:Bird:20446 WFVZ:Bird:20447 WFVZ:Bird:20464 WFVZ:Bird:20472 WFVZ:Bird:20476 WFVZ:Bird:20477 WFVZ:Bird:20481 WFVZ:Bird:20483 WFVZ:Bird:20490 WFVZ:Bird:47830 WFVZ:Bird:49754 AMNH:Bird:234136 AMNH:Bird:352520 AMNH:Bird:352526 AMNH:Bird:352531 AMNH:Bird:352535 AMNH:Bird:470683 AMNH:Bird:832603 AMNH:Bird:832604 AMNH:Bird:836423 AMNH:Bird:98112 MSB:Bird:21684 WFVZ:Bird:20461 WFVZ:Bird:20465 WFVZ:Bird:20470

B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern)

f f f f f f f f f f f f f f f f f f f f m m m m m m m m m m m m m m

358 359 346 355 359 328 321 307 352 340 350 335 325 345 341 343 327 337 350 324 316 339 346 335 333 330 324 337 341 334 306 321 329 310

22.94 20.24 22.06 21.31 23.4 20 21.5 22.22 22.55 21.5 21.1 22.2 20.7 21.9 20.1 20.6 19.7 21.3 22.9 20 20.22 20.24 21.14 22.45 22.82 19.69 21.74 21.71 19.91 21.11 19.57 19.5 19.1 20

80.46 85.4 81.04 75.5 84.3 74.66 74.45 77.14 76.81 84.9 82.5 84.6 84.7 84 86.8 84.9 81.7 84.8 81.9 84.2 75.81 80.71 82.17 77.9 79.21 73.18 79.52 80.14 74 77.29 73.52 83.1 79.2 79.8

21.45 23.9 22.25 21.6 23.25 21.66 20.89 21.81 22.78 21.7 21.8 23.1 19.5 21.5 20.7 22.3 21.1 19.2 22.7 22.2 20.43 20.79 20.11 20.72 21.27 20.41 21.11 20.91 20.38 21.67 21.63 22.2 21 19.8

208.6 198.45 213 208.8 211 200.67 194 185 211 200 203 195 207 209 213 205 204 181 214 197 188.47 200.19 194.75 195.57 184.32 202.38 193.77 200.7 195.24 197 207 194 183 185

ON NJ MD CT RI NY LA FL IA PA GA GA NJ MD NJ PA PA FL NC TX ON IA MO NJ NY ON MA RI RI MA TX PA NJ GA

21


Unusual Cal RS WFVZ:Bird:20471 WFVZ:Bird:20472 WFVZ:Bird:20473 WFVZ:Bird:20474 WFVZ:Bird:20497 WFVZ:Bird:20499 WFVZ:Bird:48010 WFVZ:Bird:50191 WFB:Bird:4816

B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) B. lineatus (eastern) Putative hybrid

m m m m m m m m n/a

319 308 323 313 311 315 302 318 350

20.8 18.8 21.2 19.5 20 19.7 18.9 20.2 23.9

77 78.5 84.8 79 75 75.9 78.3 76.7 83.2

18.4 20.3 19.9 21.9 20 19.7 18.4 21.7 25.12

189 184 195 186 192 185 186 197 212

GA PA GA GA GA GA GA TX CA

22
