| Abstract: | The Southwestern Willow Flycatcher(Empidonax trailii extimus) is an endangered Neotropical migrant that breeds in isolated remnants of dense riparian habitat in the
southwestern United States. We estimated genetic variation at 20 breedings sites of the Southwestern Willow Flycatcher(290 individuals) using 38 amplified fragment length polymorphisms(AFLPs). Our results suggest that considerable genetic diversity exists within the
subspecies and within local breeding sites. Statistical analyses of genetic variation revealed
only slight, although significant, differentiation among breeding sites( Mantel‘s r = 0.0705,
P < 0.0005; 0 = 0.0816, 95% CI = 0.0608 to 0.1034; a??sr = 0.0458, P < 0.001). UPGMA cluster
analysis of the AFLP markers indicates that extensive gene flow has occurred among breeding
sites. No one site stood out as being genetically unique or isolated. Therefore the small
level of genetic structure that we detected may not be biologically significant. Ongoing field
studies are consistent with this conclusion. Of the banded birds that were resighted or recaptured in Arizona during the 1996 to 1998 breeding seasons, one-third moved between
breeding sites and two-thirds were philopatric. Low differentiation maybe the result of historically high rangewide diversity followed by recent geographic isolation of breeding sites, although observational data indicate that gene flow is a current phenomenon. Our data suggest that breeding groups of E. t. extimus act as a metapopulation. |
| Genre: | Article |
| ProdID: | 1016031 |
| Citation Author: | Busch, Joseph; Miller, Mark P.; Paxton, E. H.; Sogge, M. K.; Keim, Paul |
| Citation Contributing Office: | Forest and Rangeland Ecosystem Science Center |
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| Citation End Page: | 595 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Auk |
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| Citation Number Of Pages: | 10 |
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| Citation Phsyical Description: | p. 586-595 |
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| Citation Search Results Text: | Genetic variation in the endangered Southwestern Willow Flycatcher; 2000; Article; Journal; Auk; Busch, Joseph; Miller, Mark P.; Paxton, E. H.; Sogge, M. K.; Keim, Paul |
| Citation Start Page: | 586 |
| Citation Volume: | 117 |
| Citation Year: | 2000 |
| Type: | citation/reference |
| Text: | Genetic variation in the endangered Southwestern Willow Flycatcher; 2000; Article; Journal; Auk; Busch, Joseph; Miller, Mark P.; Paxton, E. H.; Sogge, M. K.; Keim, Paul |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 2000 00:00 -0600 |
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