[birdky] INFO: Solution to last month's raptor quiz bird

To find out who correctly identified the juvenile Red-shouldered Hawk, check 
http://www.biology.eku.edu/kos/what_is_it.htm


Gary Ritchison
Richmond, KY

________________________________
From: birdky-bounce@xxxxxxxxxxxxx [mailto:birdky-bounce@xxxxxxxxxxxxx] On 
Behalf Of Palmer-Ball, Brainard (EEC)
Sent: Wednesday, September 24, 2008 8:51 AM
To: BIRDKY
Cc: Terry Schwartz
Subject: [birdky] INFO: Solution to last month's raptor quiz bird

The immature raptor posted as a Quiz Bird on the KOS web site last month at the 
following link:

http://www.biology.eku.edu/kos/what_is_it.htm

is a juvenile Red-shouldered Hawk.

This bird threw some of us off because it does not appear to be as boldly 
streaked on the upper breast, nor have as buffy a ground color to the feathers 
of the underparts. However, it does show several characters that are not 
inconsistent with Red-shouldered and one that is very good but hard to 
see/detect.

One thing that is clear ... this is a young hawk. It has a pale (seemingly pale 
yellowish-gray) iris (most adult hawks in our area have darker irides). It is 
heavily streaked below with clean, pale edgings to the feathers of the 
upperparts, all indicative of a juvenile (i.e. hatched earlier in the summer of 
2008).

The bird in all respects appears to be a Buteo rather than a falcon or member 
of the genus Accipiter due to the following characters: relatively bulky body, 
rather thick tarsi (legs), large feet, and short tail (relative to the length 
of the primaries).

The bird was photographed in Louisville in August, so potential expected 
candidates are Red-tailed, Red-shouldered, and Broad-winged hawks.

Red-tailed can be eliminated by the presence of streaking on the upper breast.

Broad-winged can be eliminated by the presence of patterned (barred) secondary 
feathers (obvious pattern of alternating medium gray-brown and dusky bars). 
These feathers are placed on a perched bird (and in this photo) as the block of 
feathers just above the undertail coverts (see Sibley pp. 117 & 118 for 
comparison). This bird also doesn't seem to have quite the right pattern of 
streaking/barring on the underparts, including the face, for Broad-winged.

The presence of the streaking on the throat area and the barred secondary 
feathers is consistent with Red-shouldreed Hawk. We can't see the pattern of 
tail banding very well, but what appears to be numerous bands without a 
noticeably wide, dark sub-terminal band is also consistent with Red-shouldered 
(as well as Red-tailed).

The *one* character that is definitive for Red-shouldered that can be seen if 
you look closely, is the buffy color at the bases of the primaries, visible as 
a few buff-colored (rather than whitish) edges on at least a couple of the 
inner primaries. This color difference is subtle in this photo because the 
primaries are so tightly aligned with one another and because the bird is in 
shadow. However, it is present.

I'm not sure, but the length of the tarsi and size of the feet may also be too 
great for Broad-winged? These characters are probably at least suggestive of 
Red-shouldered/Red-tailed rather than Broad-winged.

If anyone has anything to add, please do so; I'm not the best on these guys and 
could have messed something up in my discussion.

Thanks to Terry Schwartz for submitting this photo for use in our quiz.

bpb

Other related posts: