Friday, December 28, 2012

Zone-tailed Hawk, ?? more likely the same juvenile

[post note, 12/30: as noted in next post I now believe there has only been one Zone-tailed Hawk, a juvenile] As I noted in an earlier post, I found the juvenile Zone-tailed Hawk in the morning while we were doing the Christmas Bird Count at Frontera Audubon Center. That (yesterday) afternoon Pat Heirs, with whom I was doing this count, spotted this second Zone-tailed Hawk less than a quarter mile from where the juvenile had been perching. This bird was more distant so it was more of a challenge to identify it. Though we looked through my Zeis spotting scope we could not see, and I did not photograph, the wide white band (or additional smaller white bands found on females of this species) that is so diagnostic for Zone-tailed Hawks. However, as noted in Wheeler's Hawks of Western North America, "When perched, wingtips extend far beyond tertials..." The wings can obscure the white tail bands. Note that on middle pic there are some tree blurry tree leaves in front of bottom half of hawk that can distort the view)

This bird does show other field marks for adult Zone-tailed Hawk as noted in Hawks of Western North America: grayish black head, black bill, bright yellow cere, white lores and forehead,undersides of remiges grayish and barred (shows in bottom pic) and yellow legs. Birds of North America online adds the adults have a narrow white ring around their eyes and "narrow ring around eye, and narrow line along supraorbital ridge all whitish"--and this can be seen in the top photo (can be seen closer up by clicking on pic to enlarge it). And this hawk lacks the whitish undertail feathering with thin black bars as found on juveniles. Similar appearing Common Hawk (even rarer) can be ruled out because it has a short tail so the wings fall well short of tail tip on perched bird. SeEtta

Addendum: Please note that I have a super telephoto lens and camera set-up that gives me the equivalent of about 900 mm. Some photos were taken with this set-up and I digiscoped a few so I was not close to this hawk. It is important that birders and photographers not try to get close to this hawk as it is sensitive to disturbance. There are many birders who will want to see it so please don't risk flushing it as it may abandon it's roost. SeEtta