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« Life and Death of a Male Paraphidippus aurantius Jumping Spider | Main | Forest Carbon 101: How Much Carbon Does a Tree Sequester? »

Mystery Bird: Cooper's Hawk, Accipiter cooperii

Topic Categories: BirdingEducationMystery BirdsTeachingTravel
Posted on: October 29, 2009 9:59 AM, by "GrrlScientist"

tags: , , , , , ,

[Mystery bird] Sharp-shinned Hawk, Accipiter striatus, Cooper's Hawk, also known as a Chicken Hawk or Blue Darter (?!), Accipiter cooperii, photographed at Smith Point, Texas. [I will identify this bird for you in 48 hours]

Image: Joseph Kennedy, 30 September 2009 [larger view].

Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/1250s f/8.0 at 1000.0mm iso400.

Please name at least one field mark that supports your identification.

I added more images of the same bird, taken shortly after this photograph. I hope they might help you make an ID. (The photographer says this is a Sharp-shinned Hawk, Accipiter striatus. Not sure if I can get him to respond by describing his reasons for this ID, but will try).

[Mystery bird] photographed at Smith Point, Texas. [I will identify this bird for you in 48 hours]

Image: Joseph Kennedy, 30 September 2009 [larger view].

Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/1250s f/8.0 at 1000.0mm iso400.


[Mystery bird] photographed at Smith Point, Texas. [I will identify this bird for you in 48 hours]

Image: Joseph Kennedy, 30 September 2009 [larger view].

Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/1000s f/8.0 at 1000.0mm iso400.

[Mystery bird] photographed at Smith Point, Texas. [I will identify this bird for you in 48 hours]

Image: Joseph Kennedy, 30 September 2009 [larger view].

Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/1000s f/8.0 at 1000.0mm iso400.


Review all mystery birds to date.

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Comments

1

Is is a Barred Hawk?

Posted by: JohnB | October 29, 2009 12:58 PM

2

Juvenile Cooper's Hawk:
* broad, rounded wings heavily barred on undersurface
* long, rounded tail
* head extends well beyond wrists
* underparts marked with elongate teardrops extending to mid-belly.

Posted by: Sheri Williamson | October 29, 2009 1:02 PM

3

The notched tail suggests sharp-shinned, rather than Cooper's. But I find raptors hard to tell.

Posted by: Russell | October 29, 2009 1:11 PM

4

I agree with Sheri, I'm pretty sure this is an immature Cooper's Hawk (Accipiter cooperii): pale underparts with thin black streaks mostly ending at the belly; tail is rounded, pale underneath, and barred with dark bands...

I understand the key field marks that would differentiate the immature Cooper's from the very similar Sharp-shinned are: the thickness and color of the streaks below- Cooper's being relatively fine and with the lower belly mostly white (as above); that there is a reddish color on the side of the head and nape (again, as above); and the rounded vs squared tail with Sharp-shinned Hawks tail feathers being the same length, whereas the outer tail feathers being shorter than the inner feathers on Cooper's Hawks thus looking rounded (as above).

Cornell Lab of Ornithology Hawk ID

Posted by: David | October 29, 2009 5:38 PM

5

Russell - the notched tail doesn't always indicate Sharp-shinned. With Cooper's, sometimes those number 1 tail feathers are so rounded on their ends that it makes their tail appear notched. The fact that the number 6 tail feathers are so much shorter than the number 1 indicates the Cooper's. On the Pacific Coast, the average difference between inner and outer tail feathers for a Coop is about 1 inch, while for Sharp-shins it's about .25 inches.

So yes, agree with Sheri and David - juvenile Cooper's Hawk. Juvenile because of the brown streaking on the body, rather than reddish barring the adults would have. (Also lacks the dark cap that the adult would have as well.)

Posted by: Robyn | October 30, 2009 2:53 AM

6

I think I'm going to disagree with the crowd this time. The blobby nature of the streaks on the breast, the broad secondaries and heavy body, and the strong wedge shape to the tail all suggest Northern Goshawk to me, as does the apparent irregular shape to the tail bands.
Most young Goshawks show streaking to the undertail coverts, but Wheeler shows several that approach Cooper's Hawk in this.

Posted by: psweet | October 30, 2009 7:34 AM

7

no change Grrl, I'm sticking to my initial ID which supports the description by that shell collector, William!

(immediately discounting the proposed Northern Goshawk possibility because the streaking below very clearly stops short of the belly)

Posted by: David | November 1, 2009 8:14 AM

8

okay, i'll try to get the photographer to peek in here and either comment or send email to me regarding this ID. if/when he does, i'll share what he says.

Posted by: "GrrlScientist" | November 1, 2009 10:47 AM

9

note the white belly and rounded tail, both distinguishing Cooper's from Sharp-shinned...

Sharp-shinned (note tail)

Sharp-shinned (note streaking on belly)

Posted by: David | November 1, 2009 11:21 AM

10

This certainly demonstrates how challenging accipiter identification can be, but like David (and no offense intended to the photographer) I'm not prepared to abandon my original identification because this seems to me to be a rather straightforward Cooper's. It would be helpful if someone like Clay Sutton or Brian Wheeler could be persuaded to offer an opinion.

Posted by: Sheri Williamson | November 1, 2009 3:01 PM

11

I showed these photos to several people at our hawkwatch at Illinois Beach SP. 2 votes for Cooper's Hawk, 2 "why isn't this a Goshawk?".

Sharpie -- Don't think so.

Posted by: psweet | November 1, 2009 4:26 PM

12

The following is from a Colorado Field Ornithologists Bird ID Quiz and I suggest you all do the similar blow-by-blow comparison that firstly eliminates Northern Goshawk and then differentiates between a Cooper's and a Sharp-shinned... many of the telling Cooper's field marks support that the bird photographed by Joseph above is indeed a Cooper's Hawk:

"The impression of a tawny head contrasting with a paler chest points to COHA fairly strongly.

The quite dark chest streaking on a white background also points to COHA.

The unmarked white undertail coverts don't point in any direction.

The longish, and apparently quite rounded tail point strongly in the direction of COHA"

In addition:

"there are two absolute characters that we haven't dealt with. These are the position and relative size of the eye and the precise shape of the tail. The bird's right eye appears rather far forward and occupies a relatively small percentage of the bird's head, typical of COHA and wrong for SSHA. In the fairly long-appearing tail, we can see that the outer rectrices are significantly shorter than any other rectrices and that the tail is fairly graduated. This is also definitive for COHA, as SSHA, though it can show a rounded tail tip, does not have such short R6s."

Posted by: David | November 1, 2009 6:59 PM

13

psweet: Location makes Northern Goshawk a highly unlikely candidate, as both photographer Joseph Kennedy and the chair of the Texas Bird Records Committee noted in recent posts to TEXBIRDS.

Posted by: Sheri Williamson | November 1, 2009 8:23 PM

14


Someone just sent me this photo, absolutely a Cooper's Hawk (Sheri and the others are correct). Tawny head that is relatively large and projects well past the wrists, relatively long narrow body, long tail that gradually gets longer towards the center (notched appearance at tip can be shown on all 3 accipiters and is unreliable), wings are fairly straight along the trailing edge, streaking is limited to chest and flanks. All these traits combined identify it as Cooper's, there are many reasons why this bird is not a Sharp-shinned or Goshawk but that would make for a long e-mail.

Jerry Liguori

Posted by: Jerry Liguori | November 2, 2009 12:06 AM

15

Thanks for the confirmation, Jerry!

For those who might not be familiar with Jerry's work, he's the author of Hawks from Every Angle: How to Identify Raptors In Flight published by Princeton University Press.

Posted by: Sheri Williamson | November 2, 2009 1:10 AM

16

Thanks Jerry!

(Having a fight with Amazon over the Ray Comfort version of Origin; is there another source for your text?)

Posted by: David | November 2, 2009 6:35 AM

17


You can get the book at most book stores or a search on line will work. The Princeton University Press site to order is:

http://press.princeton.edu/titles/8025.html

Jerry

Posted by: Jerry Liguori | November 2, 2009 10:12 AM

18

Allright -- I'll concede gracefully -- it's a Cooper's Hawk. For what it's worth, one of our counters who initially voted for Goshawk changed his mind on further review.

As far as locale, I agree that Smith's Point makes Goshawk unlikely. (Actually, I think that the date is a pretty good strike against, as well.) But ... Smith's Point gets an awful lot of birds. I know from a season at Corpus Christi, as well as seasons up here, that one can expect several unlikely birds a season in such a situation.

Posted by: psweet | November 2, 2009 5:58 PM

19

Thank you Jerry

Posted by: David | November 3, 2009 6:40 AM

20

One of the factors that says "Cooper's Hawk" to me is the relatively large, longish, blocky head. To me (here in CT), Sharpies seem to have relatively smaller, rounder heads. And that tail sure looks rounded to me.

This was an interesting and informative exchange.

Posted by: Sarah | November 4, 2009 12:20 PM

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