found a Rufous/Allen's hybrid zone on the Oregon/California border 300 kilometers long and 90 kilometers wide. Detecting hybrids in the field will not likely be easy, but we need to keep in mind the possibility that some of the birds we identify as one species or the other, even those based on a combination of field marks may be hybrids.
Having said that, I agree the bird in the excellent photos is likely Allen's beyond the margin of error.
On Sat, 12 Jul 2025 10:16:59 -0700, "Peter Pyle via groups.io" <ppyle...> wrote:
>Good subject right now and excellent posts. >Another reason the initial ALHU is a juvenile male is the heavy bronze spotting to the throat, whether or not there is iridescence as well. Juvenile females have cleaner white throats while adult females have cleanish white throats with a patch of iridescence in the center. >Outer rectrix width is indeed very useful, with little or no overlap within each age/sex group. So aging and sexing needs to precede analysis of rectrix width and, luckily, it is easy enough to do this based on the above characters. >Ethan's cautions and info on timing are spot on. There's a good paper by Howell and Gardali on this in Journal of Field Ornithology a number of years ago that should be easy to locate on line. >Cheers, Peter > > >On Jul 12, 2025, at 09:47, Ethan Monk via groups.io <z.querula...> wrote: > > >?Hi, > Immature male feels safely supported by the iridescent gorget feathers coming in at the very side of the gorget (bottom of auricular-ish), and the more inner rectrices often have more green showing in females. So for example on the R2 (second rectrix from center) you will often have green sandwiched between the rufous and black on the females. The green will often be more extensive on the R1 in females, etc. >When it comes to the finer points of the ID, which is importantly done based on age/sex, I think Zac's explanation did a good job. >I will say, the width of the outermost rectrix-- R5 --has burned me before. The apparent width of that tail feather can change a lot based on the angle of the photo, and I just stay away in cases where it feels even vaguely ambiguous. But I know people better than me disagree. >As this conversation handily illustrates, non-adult male Rufous and Allen's Hummingbirds are generally not identifiable under standard field conditions, which is why Allen's Hummingbird flags as "rare" in eBird for Contra Costa County in late June. Most adult male Allen's depart earlier in the month, so it will get really hard to find a "safe" Allen's by the end of June. Obviously, Allen's are still around, so if you go around photographing tail feathers you will find plenty of Allen's (females and immatures) right after they flag in eBird, but it's worth noting Rufous Hummingbirds start to show up at end of June, too. By second week of July, Rufous Hummingbirds are very present in the interior parts of the East Bay. And presumably the more coastal parts too, but harder to say for obvious reasons! >Ethan >On Fri, Jul 11, 2025 at 6:59?PM Bob Lewis via groups.io <RLewis0727...> wrote: >Wow, I just sent Claude a note saying it was a female. Reasoning being the tips of R3-R5 are bright white, and immature male is more tan-tipped. I do think the R5 is quite narrow, supporting Allen's. If indeed it's a male, then I think Zac's comments regarding the absence of a notch (or nipple-like tip) is convincing, and it's an Allen's. But obviously I have no real clue!!Bob >On Friday, July 11, 2025 at 06:48:58 PM PDT, Zac Denning via groups.io <zdenning1...> wrote: > > >Hey Claude, >This is a juvenile male, so the ID is a bit more subtle than for adult males. Unfortunately, by this time of year, my understanding is that the adult males have mostly left the scene, so the tougher birds are what were left with ... >Others are more expert, but for what it’s worth, here’s my take:The R2 feather (next to innermost tail feather in your 3rd shot) appears to be missing the slight notch that juvenile male Rufous would usually show. If you happen to also have a shot of the outermost tail feather that’s separated enough from the others to see the feather width, that might help clarify further. >In terms of whether the 3rd photo (with spread tail) meets the reviewers’ threshold for listing as Allen’s, I’m not sure. The default right now would be listing all these birds as a slash (Allen’s/Rufous Hummingbird). >If you don’t get definitive feedback from a reviewer/expert on this email thread, and if you have the reviewer’s contact, you could list as a slash on eBird, reach out to them, then wait for confirmation before proceeding with a more definitive ID. Otherwise, you could try listing as Allen’s, and say in the eBird description that you’re seeking reviewer feedback. If your reviewer responds (whatever the outcome), please be sure to thank them for their unpaid work to keep eBird data accurate! It’s not an easy job. >Maybe someone has another suggestion, but that’s usually how I’d usually handle this type of situation. >I hope that helps. >Zac DenningAlbany > > >On Fri, Jul 11, 2025 at 5:44?PM Claude Lyneis via groups.io <cmlyneis...> wrote: >After seeing several eBird reports of Allen’s Hummingbirds in U.C. Blake Garden I thought I would try again to get some definitive photos that would pass expert judgement and not have to be labeled Allen’s/Rufous. A couple of these photo show good detail of the tail feathers, but is that enough? There were several of these Hummers buzzing around and at least one Anna’s. Blake Garden seemed a rather magical place hidden away in Kensington. >Here is an album with four photos of the bird. ><54648983475_d4aa3e69a4_c.jpg> >Allen's Hummingbirdflic.kr > > >Claude <Lyneiscmlyneis...>://www.youtube.com/bhsvideodadFlickr Photos at https://flic.kr/ps/36it5P > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- Joseph Morlan, Pacifica, CA
