To add to Jamie's field mark summary, a juvenile Broad-winged Hawk has very low-contrast stripes on the underside of the tail (except for, as he points out, a dark terminal band). Additionally, the breast of a juvenile Broad-winged, in addition to having larger, less dense dark markings, tends to have markings more on the sides of the breast, with a mostly unmarked upper center.
An adult Broad-winged Hawk's tail has only two black bands, with a partial third band at the base, broken by the undertail coverts; thus many fewer bands than this bird shows. (And, of course, an adult Broad-winged would have a much different head and breast pattern)
Amongst the accipiters, a juvenile Sharp-shinned would have a different breast pattern, with brown instead of blackish streaks, and the streaks would not be formed into lines like rivulets of water as they are on Cooper's, as seen in this bird. Juvenile Goshawk would have an eye line and a breast pattern more like Sharp-shinned than like Cooper's. And, as Jamie mentions, the underside of the tail would have irregular, wavy tail bands. All adult accipiters have a breast pattern vastly different than this bird.
Someone mentioned the tail looking wide; that appears to be an artifact of foreshortening, due to the angle of the shot.
I see nothing about this bird that would indicate it is not a juvenile Cooper's Hawk.
== Michael Hobbs
== www.marymoor.org/birding.htm
==
BirdMarymoor at frontier.com
From: J. Acker
Sent: Thursday, February 8, 2018 6:25 PM
To: 'Alexandra MacKenzie' ; 'tweeters'
Subject: RE: [Tweeters] Need Raptor ID Help
This is a juvenile Cooper's Hawk for the following:
The rectrices get shorter the further out from centerline -; hence the rounded tail appearance of a Cooper's Hawk (Vs. Sharp-shinned).
The terminal band in the photo is the same width as other dark bands. In a juvie Broad-winged, the terminal dark band is noticeably wider and darker than other bands.
The tear-drop shaped markings on the breast are indicative of a Cooper's hawk (vs. sharp-shinned). Those on a Broad-winged are larger and less dense.
A Goshawk would have irregular tail bands, while these are very regular.
J. Acker
owler at sounddsl.com
Bainbridge Island, WA
From:
tweeters-bounces at mailman1.u.washington.edu [mailto:
tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Joe Mackie
Sent: Thursday, February 08, 2018 5:58 PM
To: 'Alexandra MacKenzie' <
mizmak at gmail.com>; 'tweeters' <
tweeters at u.washington.edu>
Subject: RE: [Tweeters] Need Raptor ID Help
This is one of the most interesting raptor ID challenges I've seen in a long time. BWHA seems far-fetched (I've never seen one perched up). Accipiter seems more likely. Goshawk? Whatever, it's a juvenile. Hmmm….this is fun. Can't wait to hear from Bud.
Joe Mackie
Bellingham
From:
tweeters-bounces at mailman1.u.washington.edu [mailto:
tweeters-bounces at mailman1.u.washington.edu] On Behalf Of Alexandra MacKenzie
Sent: Thursday, February 8, 2018 3:37 PM
To: tweeters <
tweeters at u.washington.edu>
Subject: Re: [Tweeters] Need Raptor ID Help
UPDATE: Between Tweeter comments (some made privately) and Flickr comments, I have about half Broad-winged Hawk IDs and half Cooper's Hawk IDs, but a Flickr commenter just suggested immature Northern Goshawk, which looks good, too! Awaiting final determination from Bud Anderson. Thanks for all the input, everybody--hawks are hard!
Alex
On Thu, Feb 8, 2018 at 2:30 PM, Stewart Wechsler <
ecostewart at gmail.com> wrote:
Alex,
I would agree with your first assessment, that it is indeed a Cooper's Hawk. Look at how narrow the final black band is on the tail, and compare it to photos on the internet of Broad-winged Hawks, with broader final black bands, and may be fewer black bands. That said, I am not certain it isn't a Sharp-shinned Hawk. It would be helpful to get an idea of the size, crow-sized for a Cooper's , big jay sized for a Sharp-shinned, but the tail on your photo shows the better rounding at the end, that is more a feature of the Cooper's Hawk, while the Sharp-shinned is a bit more squarred at the end, at times with a better defined notch in the center. Also, we don't get many Broad-winged Hawks in our area, which is partly why I always want to know where a photo was taken, ideally with some habitat information..
-Stewart Wechsler
www.stewardshipadventures.com
Message: 7
Date: Thu, 8 Feb 2018 08:09:22 -0800
From: Alexandra MacKenzie <
mizmak at gmail.com>
Subject: [Tweeters] Need Raptor ID Help
To: tweeters <
tweeters at u.washington.edu>
Message-ID:
<
CAJfxVzeonira691GkK7rSqyNFPh57ecAP1ufyUOhXxn2k0mGaA at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
In Sep 2014 I took a photo of a hawk at Magnuson Park in Seattle and posted
it on Flickr as a Cooper's Hawk. Recently a birder commented that he
thought it was a Broad-winged Hawk. I thought that unlikely but am now
confused by his field mark comments. The photo and comments may be found
here:
https://www.flickr.com/photos/mizmak/15199769280/
If the experts can weigh in, I'd greatly appreciate it.
Thank you,
Alex MacKenzie
Seattle
mizmak at gmail.com
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