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All: I've received a some useful comments from three paramount experts on western birds on our Halifax Hermit Warbler. Kimball Garrett is Ornithology Collections Mamager at the Nat. Hist. Mus. of Los Angeles and a co-author of the fine Peterson Field Guide on Warblers. Joeseph Morlan is an active field oornithologist and teacher of field ornithology in California and has a very useful website. Will Russell is a senior field ornithologist living mostly in SW USA and is listowner/moderator of the Frontiers of Field Identification website. As I expected, all believe it to be a pretty good Hermit Warbler, although two especially stress that the situation is not simple. Kimball Garrett writes: "First, it must be acknowledged that there is sometimes a decoupling of phenotype from genotype in the Townsend's/Hermit/B-t Green complex. Birds that look phenotypically "pure" can indeed have some genetic markers of another parental species, and I'm sure that some birds that look phenotypically intermediate might actually be "pure" genetically. The slight olive wash on the back of your bird is fine for Hermit in fresh fall plumage. That, in itself, is not necessarily suggestive of intergradation (unless the olive is really brighter and more prominent that it appears on my monitor). The dinginess to the auriculars is not at all troubling to me. I'm more troubled by the fine black streaking on the flanks. I'm more troubled by the fine black streaking on the flanks. At most, "pure" Hermits should show just a few, very fine streaks on the sides, so your Halifax bird might be a bit outside the curve there. Whether this suggests intergradation or just a broader range of phenotypes of Hermit than I am familiar with, I don't know." In short, I agree that your bird is not an obvious (e.g. F1) hybrid between Townsend's and Hermit. It is quite possibly a "pure" Hermit, but the degree of hybridization in these two taxa is so great that it is also easily possible that the bird has hybrid ancestry." Joe Morlan writes: "I showed the photos to Dan Singer last night and neither of us can come up with any solid reason why the bird might be considered a hybrid. Certainly it would not raise any eyebrows if seen in California. We are guessing it's a young male, but I'm not all that clear on the extent of variation between different age/sex classes. I suppose it might be an adult female. Anyway, lacking genetic data to the contrary, I would certainly endorse it as a Hermit Warbler, not a hybrid. It does not look like any of the hybrid types we see in California. The yellow chest is a dominant trait and all the presumed hybrids I have seen had a yellow chest. I have seen one white-chested hybrid specimen, but it had a Townsend's Warbler face pattern." And Will Russell writes: "I suspect Hermit x Townsends combinations, including backcrosses, are so complicated that I would be hesitant to say anything on that score...but there's nothing obvious in the images to suggest a hybrid (but see note below about the dark crown streaking) given what I know. I don't think this is an HY female. My guess is HY male (I should wonder about AHY female too...); the face is too yellow, the underparts too white, the wingbars too bold, and the crown too dark. Speaking of the dark streakings on the crown, I'm not sure I've noticed them before in Hermits...but that's probably because I haven't looked. None of the guides mention or illustrate them. Are they apparent in life?" So, I think everyone may feel comfortable about accepting the bird as a Hermit Warbler on their life lists, even with Kimball Garrett's sensible caveats. My own belief is that it's an HY (Hatching-Year) male, in the belief that the Black throat should be less veiled and the auridulars darker in an AHY (After-HY) female. But, it's also good to ponder the variability of nature and recognize that things don't always fall neatly into our attempts at categorization. That's why photgraphs and lots of picky written details are often needed in documenting birds. All best, Ian McLaren
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