Sunday, November 27, 2011

The Birder Thought Process

Posted by Pat Bumstead

Looking out my kitchen window a few days ago, my eyes nearly bugged out of my head. I had company, majestically perched atop my feeder pole. Needless to say this was the only bird in the yard at the time.

This beauty sat on the feeder pole for 32 pictures, then moved over to the poplar tree for 3 more to show off the markings on his back. (Measuring bird movement in minutes is so last year...)

Finally he moseyed over to hide himself in the spruce tree, to sit and watch the cats in their run, which is thankfully fenced on top.

The first rule of bird watching is that no bird shall go unidentified, particularly one this obliging. Raptor identification can be quite a challenge, so I thought I would share the birder's thought process in case you're ever in this situation. It went something like this.

Holy Crap!

Camera! Camera!

Binos! Binos!

Wait is this bird injured? Whew, no it's just wearing some of its lunch.

OK I think this is either a juvenile Cooper's Hawk or a juvenile Sharp-shinned Hawk.

Oh wait - it could be a juvenile Northern Goshawk...

Juvenile raptor identification? Hmm. I'll think about it over lunch. Maybe a liquid lunch.

Fortunately a fellow birder dropped by in the afternoon. I pulled up the pictures on my computer and we got down to the serious business of identifying my hawk.

Eyes: Cooper's straw colored, Sharpie and Goshawk yellow. Well that helps.

Breast: Cooper's and Goshawk heavily streaked with brown, juvenile male Sharpies have dark brown streaking. Thank you so much.

Tail: Cooper's is rounded, Sharpie is squarer than Cooper's, Goshawk is wedge shaped and all have white bands. Moving along...

Back: Cooper's is brown with white spots, Sharpie is brown, Goshawk is mottled brown. Oh look, is that Black-billed Magpie out the window? A nice, clear black and white bird?

Oh right, the hawk. That's a fairly noticeable pale eyebrow - let's work on that.

Pale supercilaries on Coopers, Sharpies, Goshawks...

Location is often a good clue, except that all three are found here. Oh wait, it's November so the Sharpies have (probably) migrated. We'll eliminate them.

At this point we had a variety of bird books spread across the table, had scrutinized every photo, and killed a lot of time. We were running out of field marks to check, and then we looked at the undertail coverts.

Cooper's is entirely white, Goshawk is white streaked with brown. EUREKA! I had photos of a juvenile Cooper's Hawk.

This whole process took two of us a great deal of time, pouring over bird pictures, scrutinizing every body part on the bird, explaining to each other what worked, what didn't and why. Juvenile raptor identification can be brutal - it couldn't have been much more complicated if we were trying to design a jet engine from scratch.

Is this a great hobby or what?!


  1. It looks like an immature Coopers Hawk to me. Sharp-shinned hawks have legs that look like #2 yellow pencils and the shin bone is prominent. Coopers Hawks have legs that are filled out. But of course, the experts are often mistaken.

  2. I just posted a good example of the Immature Coopers Hawk and an Adult Coopers Hawk here:

  3. Pat, You've happened upon one of the greatest conundrums facing North American birders. Thus, your post about the thinking process is perfect for this scenario!

    With all due respect to you and our commenter Abe, after consulting half a dozen field guides, I am convinced that you have a juvenile Sharp-shinned. Here is my reasoning:

    First, when I participated in hawk banding, we had both a juvenile Sharp-shinned and Coopers within minutes of each other and I photographed them. The difference in eye color was amazing. Young sharpies have yellow eyes, while young Coopers have light yellow to almost pearly white eyes. Your bird has distinctly yellow eyes. A Cooper's would be lighter.

    Also, based on size, as compared to the shepherds hook and feeder, the bird seems Sharpie-sized (smaller), but their sizes do have some crossover.

    Sibley mentions coarse brown streaks on the breast and belly of the juvenile Sharpie. I think your photo matches Sibley's drawing very well. Also the thinner legs and narrow white tip on the tail feathers.

    NatGeo6 for Sharpie also mentions the thinner legs, and also the smaller head and neck. NatGeo6 also mentions the reddish brown breast streaks, a pale eyebrow, narrow white tip on tail.

    Peterson mentioned the thickly streaked with rust brown on underparts on Sharpies. Coopers have thicker white band on tail tip. Immature Cooper's have whiter, more finely streaked breast.

    Stokes also mentions brown upper parts with white spots along scapulars. Coopers tend to have warmer brown napes, where yours has a darker nape like a imm. Sharpie.

    Anyway, I hope this doesn't confuse the issue more. I hope more birders will weigh in here. We are all bound to learn a lot from the exercise.

    Ah, the fun and challenge of birding!

  4. In regards to your reference to a birder's thought process, you are so right! And so funny. I couldn't have verbalized the process any better myself. I could feel your heart racing when you initially spotted him and the question in your brain - grab the nockies or the camera? I have to agree with the speculation that it is a juvenile sharp shinned, and I so appreciate the post and the comments, as I have identical pictures from my shepherd's hook and have been mulling over the i.d. for a few weeks!

  5. Pat, your thought process is similar to mine only I never think of the binocs, instead I think of focusing through the viewfinder.

    I'm also of the mind that the ID is juvie Sharp-shinned for the reasons Robert pointed out.

  6. I'll third the Sharp-shinned vote. In my experiences, the mottling/streaking on the chest is more elongated on a juvenile Coopers hawk, and often times a darker brown. Here, the spotting on the breast is more horizontal that vertical. While I've never actually seen a sharp-shinned myself, this bird pictured here (great photos by the way!) looks dissimilar from the Coopers Hawks that I've seen.
    Thanks for sharing.

  7. Also, the squared end of the tail points towards a Sharp-shinned.

  8. Jerry Liguori, a fellow Utah birder, author, my favorite hawk expert, and a heck of a nice guy weighed in. He says Sharp-shinned juvenile.

    See folks, this is part of why birding is fun. ID challenges.

  9. I agree, sharpie. coops dont have such a white eyebrow, and the eyes are definitely the yellow of a sharpie (not straw like a coop). I also find that sharpies (more so in adults but also as juvies) have more of a rounded "cheek" marking/delineation. Finally, the shape of the streaks on sharpie chests are different than coops, and go further down the chest (coops streaks are concentrated at the top)

  10. oh, and also, in the hand there is actually no overlap between size in these species....but in the field they can appear very similar.