Join/Renew (2022 Dues)
News from https://groups.io/g/SanDiegoRegionBirding

Eastern Towhee -hybrid?

Eastern Towhee -hybrid?
By – 8:18 pm
Logistics: located in the backyard of The Cascades keyboardist David S. Who has been very accommodating to visiting birders. A very aggressive Karen type was reported along Calexico. I would strongly suggest birders keep to Herber St and the back alley to observe the bird. GPS (32.6193571, -116.1872576)Plumage: Plumage wise this bird appears to be completely in line for a ‘red-eyed’ Eastern Towhee. Back is solid black with no white spots visible, white wing patch is bold and noticeably wide, while the flanks are a deep chestnut color. The issue being that Caleb Strand has recent issues experience with clutches of birds in the hybrid zone. An F2 generation clutch of a hybrid with an EATO produced offspring ranging from being phenotypically pure to having hybrid features:“Having been in the hybrid zone over the last year, I’ve found that mixed-gene birds vary from looking phenotypically like EATO to SPTO and everything in between. Had a 50/50 hybrid female paired with an eato-looking male giving spto calls and they were feeding young in a nest. I so helped band a brood of mixed-gene immatures that varied from looking perfect for eato to having white spotting on the coverts. Plumage is not going to be reliable on telling if a bird is “pure”.“ -Caleb S.Calls: The bird was recorded giving Spotted Towhee like calls in the am and Paul heard it giving more typical Eastern Towhees. There is a question of whether these calls are innately programmed via genetics or learned in the nest. Will Anderson sums up this issue succinctly with his post:Will Anderson posted the following to advanced bird ID: “This is the long answer to this question. These towhees don’t actually have hard data on if the call is innate vs learned, but the assumption is that it is innate. There is evidence that it could be learned, since the range of variation across both birds populations is vast, which goes against the idea that it is innate, but it hasn’t been proven. Beyond that, if Towhees do learn their calls, it would mean that this bird grew up within Spotted Towhees, hence the call, which means the only way to be sure of this bird in any way would be to get genetic evidence. If this call is the great plains type, then you’re probably looking at a hybrid, since it is almost impossible to find a pure bird within that range. I may have been overzealous in calling it 100% a hybrid, but the odds are that this bird is a hybrid.”TLDR Overall consensus is growing that this bird is likely a hybrid unless genetic evidence can prove otherwise.Best,Tom Ford-HutchinsonSan Diego, CA