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Rick Baumhauer
02-09-2009, 12:58 AM
http://gallery.me.com/rickbaumhauer/100123/1088_200_130041/large.jpg

I shot this bird on a very windy, cold day in Springfield, MA. My initial ID was a Juvenile Cooper's Hawk, but I'm leaning towards a Juvenile Sharp-shinned now, based on the nature of the breast streaks - they have the sort of "watercolor" look I'm seeing on Sharpies, rather than the sharper, more defined streaks on the Cooper's.

The bird did seem too large to be a Sharpie at the time, but I didn't have anything to compare it to, so my best guess is a juvenile female Sharp-shinned.

http://gallery.me.com/rickbaumhauer/100123/1166_250_130553/large.jpg

http://gallery.me.com/rickbaumhauer/100123/1189_200_131556/large.jpg

Doug Hitchcox
02-09-2009, 09:31 AM
I'll agree with Juvenile Sharp-shinned. I have trouble with the breast markings in the field but juvie sharpies are suppose to have a paler brown or dull reddish brown against a buffy white background - tear drop shaped that extend far down the breast... looks like this bird to me. A lot of other field marks vary with coopers/sharpie juveniles but one more thing to look at is the tail tip: typically larger in Coopers and this one looks pretty small

Roy Priest
02-09-2009, 04:21 PM
This to me is a mature Coopers hawk. Rounded tail and sturdy legs. The breast coloration and the yellow eyes seem to indicate a first or second year adult.

[quote=Rick Baumhauer;210613]

I shot this bird on a very windy, cold day in Springfield, MA. My initial ID was a Juvenile Cooper's Hawk, but I'm leaning towards a Juvenile Sharp-shinned now, based on the nature of the breast streaks - they have the sort of "watercolor" look I'm seeing on Sharpies, rather than the sharper, more defined streaks on the Cooper's.

The bird did seem too large to be a Sharpie at the time, but I didn't have anything to compare it to, so my best guess is a juvenile female Sharp-shinned.

Doug Hitchcox
02-09-2009, 05:02 PM
Does anyone know how long accipiter's keep their yellow eyes?
Doing a little more reading I guess I'm leaning toward Coopers. I would expect a Coop to look 'big headed' but I guess the more rounded tail and thicker tarsus than expected for sharpie wins the bet.

Rick Baumhauer
02-09-2009, 05:16 PM
Danged small accipiters! You'd think they could look like one, or the other, but Nooooooo. Honestly, this bird looks very much like some of the Sharpies in Brian Wheeler's books, so I'm still tempted to lean that way.

Wait until you see my other problem ID tomorrow morning - I thought it was a Red-shouldered when I shot it, but I'm now leaning towards a really big female Cooper's.

Roy Priest
02-09-2009, 05:23 PM
Does anyone know how long accipiter's keep their yellow eyes?
Doing a little more reading I guess I'm leaning toward Coopers. I would expect a Coop to look 'big headed' but I guess the more rounded tail and thicker tarsus than expected for sharpie wins the bet.

The older the bird the redder the eyes. Pale yellow, yellow, amber, red then deep red.

Rich Williams
02-09-2009, 07:19 PM
I agree with the Coopers ID.

Ed Grella
02-09-2009, 07:27 PM
Coopers Hawk!

John Chardine
02-10-2009, 09:27 PM
I'm not so sure (2nd the danged small accipiters!). Agree this is a young bird- yellow eye. However, my standard ref. -Sibley- has "thin, dark streaks" on the Cooper's breast, and "course, brown streaks" on the Sharpie. These look like course brown streaks to me so I'm going with a Sharpie. Had a Sharpie in my yard yesterday, eating a starling. This is what the breast looked like. To me it looks like the patterning on the bird in question.

Any other bids ladies and gentlemen?

Rick Baumhauer
02-10-2009, 11:55 PM
John - that pretty much matched my reasoning. The shots I've seen of juvie Cooper's (in Wheeler, etc) show darker, more defined streaks, where the juvie Sharpies have lighter, less-defined markings.

By the way, how do I get thumbnails to display?

Roy Priest
02-11-2009, 12:52 AM
John - that pretty much matched my reasoning. The shots I've seen of juvie Cooper's (in Wheeler, etc) show darker, more defined streaks, where the juvie Sharpies have lighter, less-defined markings.

I'm a little confused as to your logic. The first thing is that this bird and the other you posted as a Coopers are both adults. The colours and markings on the breast are almost the same. The coopers you've just posted is just an older bird and the colouration is deeper. However you identify one as a sharpie (juvenile no less) and the other a Coopers.

Rick Baumhauer
02-11-2009, 07:29 AM
Roy - I'm basing my IDs on my reading of Wheeler's, considered the photographic ID guide to North American raptors. Sharpies and Cooper's, particularly juveniles, are notoriously difficult to tell apart, so it doesn't suprise me that there is disagreement on this bird.

Based on the size of the two birds (the bird in the other topic was MUCH bigger than this one, though that may just be an adult female vs. a juvenile male) and the overall markings (as John points out, above), I'm still inclined to call this a Sharpie - you are free to feel differently.

John Chardine
02-11-2009, 09:01 AM
I'm a little confused as to your logic. The first thing is that this bird and the other you posted as a Coopers are both adults. The colours and markings on the breast are almost the same. The coopers you've just posted is just an older bird and the colouration is deeper. However you identify one as a sharpie (juvenile no less) and the other a Coopers.

Roy- my understanding is that the yellow eye of the bird in this post makes it an immature not adult. All the field guides I have consulted note this. The bird in Rick's later post has a dark, reddish eye which makes it an adult. The breast markings of immature Sharpies and Cooper's are quite different but in adults, the markings are much more similar between species. Does this clear up the confusion or make it worse?

Roy Priest
02-11-2009, 03:51 PM
Roy- my understanding is that the yellow eye of the bird in this post makes it an immature not adult. All the field guides I have consulted note this. The bird in Rick's later post has a dark, reddish eye which makes it an adult. The breast markings of immature Sharpies and Cooper's are quite different but in adults, the markings are much more similar between species. Does this clear up the confusion or make it worse?

John, I sent the pic to a friend of mine who like me has had and flown both Sharpies and Coopers. Here's what he wrote back.
"I'd guess first year adult ( eyes not red ) Coopers ( tail looks
rounded as opposed to a 'V' that a Sharpie should show."
So I'll stick with my Coopers ID.:)

John Chardine
02-11-2009, 07:36 PM
I want to get to the bottom of this! I did a Google search for immature Cooper's Hawk and got back a lot of images. Then did a search on BPN and found these:

http://www.birdphotographers.net/forums/showthread.php?t=23134&highlight=cooper%27s+hawk
http://www.birdphotographers.net/forums/showthread.php?t=21020&highlight=cooper%27s+hawk
http://www.birdphotographers.net/forums/showthread.php?t=5783&highlight=cooper%27s+hawk (scroll down to see the Cooper's)
http://www.birdphotographers.net/forums/showthread.php?t=5799&highlight=cooper%27s+hawkhttp://www.birdphotographers.net/forums/showthread.php?t=3009&highlight=cooper%27s+hawk

All of them show the thin, dark brown striping that Sibley says is characterstic of the Cooper's Hawk, and which the bird in Rick's OP just doesn't show. Have a look and see what you think.

Rick Baumhauer
02-11-2009, 08:19 PM
John - thanks for pulling those up. Another thing that I noticed on at least a couple of those shots is the dramatically shorter tail feathers that are visible, which are not visible on my shots, and account for the Cooper's more rounded tail vs. the more square tail of the Sharpie (as noted by Sibley).

I should correct something I said earlier today, about accipiter juveniles being particularly difficult to distinguish from each other. As I've done more research (Cooper's and Sparpies are rare sightings for me), it's become clear that the adult birds are more difficult to tell apart based on markings, as they are virtually identical. The nature of the streaks on the breast does seem to be a pretty consistent means of distinguishing between the juveniles, at least in the sources I've found.

I was also amused to find this in Pete Dunn, David Sibley, and Clay Sutton's "Hawks in Flight":

"Distinguishing one accipiter from another is not easy. It is, in fact, one of the most difficult identification problems facing hawk watchers. Even veteran observers do not always agree. Arguments about identification of accipiters may well account for more broken friendships and more failed marriages between hawk watchers than all other causes combined."

:)

Roy Priest
02-11-2009, 08:20 PM
I want to get to the bottom of this! I did a Google search for immature Cooper's Hawk and got back a lot of images.

John, those were all great pics of an immature coops but in my opinion this is a first year adult Coopers.

Isaac Green
02-11-2009, 08:57 PM
Let's see if this helps -- eye color can be an indication of age, but when looking at feather patterns, the phase of the plumage needs to be looked at. The bird's yellow eyes says it is young, but it has adult plumage -- the juveniles are more brown, adults more grey. So, as Roy pointed out, this is a young adult bird, so it needs to be compared to adult coops and sharpies, not juvenile (aka immature).

IMHO, this is a coop for the following reasons,
1) Wide white terminal band on the tail
2) Outer tail feathers appear shorter than inner tail feathers
3) legs appear too stout for sharpie
4) head seems more in line with coop (sharpies have smaller head to body size) (Photo 3 he's stretched out his neck which makes his head look smaller)
6) Rick's initial feeling on size

That being said, these are hard hawks to tell apart. I volunteer rehabbing raptors, and sometimes it is hard to tell even when you have them in your hand.

Rick Baumhauer
02-11-2009, 09:53 PM
Well, this pretty much seals it for me. When I arrived at work today, I found a pair of large raptors in a tree across the street from the parking lot, just a couple trees down from where the bird I shot last week had been perched. One of the birds flew when the lot attendant came out of his booth (I can't be too mad, since he's acting as my "spotter", alerting me when raptors show up looking for a quick meal from the sparrows he feeds), but the other stuck around long enough for me to get a few shots (but no clear shots without branches).

http://gallery.me.com/rickbaumhauer/100123/1547_125_090659/large.jpg

http://gallery.me.com/rickbaumhauer/100123/1548_400_090747/large.jpg

This bird is (I think without a doubt) a Cooper's Hawk, and is much, much larger than the bird I shot last week. In the second shot, you can see that the outer tail feathers are substantially shorter than the central feathers, so while it's true that you can see a difference in length on last week's bird, the difference here is much greater. In the first shot, you can also see the more defined, darker streaks on the breast that seem diagnostic of a juvenile Cooper's.

As I said, these are not birds that I see very often - I don't think I've ever previously seen a Sharpie in the wild, and have only had fleeting encounters with Cooper's on a couple occasions. After today, there is absolutely no doubt in my mind that the bird I shot last week was a Sharpie.

John Chardine
02-12-2009, 10:03 AM
John, those were all great pics of an immature coops but in my opinion this is a first year adult Coopers.

That's an interesting twist Roy! I see now what you were getting at in an earlier post when you said this bird was adult. First, the phrase "first year adult" is somewhat oxymoronic, i.e., I don't think it can be both based on what I know about timing of moult in these species. Assuming Rick's images were taken recently (note to Rick- important to mention dates images were made!), the first year bird in the OP fledged in summer/fall of 2008 which would make it a few months old. The bright yellow eye of this bird supports this age estimate, although rarely, 2nd year birds will also show a yellow eye (see Snyder and Snyder 1974, Condor 76:219-222). According to the Birds of North America account of the Coopers Hawk, the juvenal plumage lasts until about 11-16 months of age at which time the bird experiences a complete moult to adult plumage.

So, if you are saying that the bird is in adult plumage then it has to be in its second year of life, in this case fledged in summer/fall of 2007. As mentioned, a bird this old could still have a yellow eye but it is rare. Females apparently take longer to attain a red eye than males, so if this is a yellow-eyed adult, then it is much more likely to be a female, which also implies that it should be a relatively big bird, which, based on Rick's comments, it wasn't.

As to Rick's later images, this bird for sure shows the marks of an immature Coopers.

Roy Priest
02-12-2009, 05:04 PM
That's an interesting twist Roy! I see now what you were getting at in an earlier post when you said this bird was adult. First, the phrase "first year adult" is somewhat oxymoronic, i.e., I don't think it can be both based on what I know about timing of moult in these species. Assuming Rick's images were taken recently (note to Rick- important to mention dates images were made!), the first year bird in the OP fledged in summer/fall of 2008 which would make it a few months old. The bright yellow eye of this bird supports this age estimate, although rarely, 2nd year birds will also show a yellow eye (see Snyder and Snyder 1974, Condor 76:219-222). According to the Birds of North America account of the Coopers Hawk, the juvenal plumage lasts until about 11-16 months of age at which time the bird experiences a complete moult to adult plumage.

John, yes my explanation was indeed flawed. The bird would just be finishing the moult into adulthood.

So, if you are saying that the bird is in adult plumage then it has to be in its second year of life, in this case fledged in summer/fall of 2007. As mentioned, a bird this old could still have a yellow eye but it is rare. Females apparently take longer to attain a red eye than males, so if this is a yellow-eyed adult, then it is much more likely to be a female, which also implies that it should be a relatively big bird, which, based on Rick's comments, it wasn't.

The eyes don't magically turn a different colour when the moult is finished or nearly finished. Some change ,sooner or later than others. It, judging the age through the eye colour, is a generalization. If you look at the pics you posted of the immature coops you will see one pic where the eye colour of one of the birds is a deep amber colour not yellow, but that doesn't mean it's an adult.

As to Rick's later images, this bird for sure shows the marks of an immature Coopers.

Yep Coopers for sure.