Thread: Cooper's?

The breast feathers pattern is very different than the juvenile you identified for me earlier - and the colors, eye and crest seem different than Julie's or the juvenile - the tail doesn't look very squared off, but this angle isn't good - but there looks to be a wider white stripe. Is this probably a Cooper's Hawk? large enough bird that the crows stayed away (the crows harass a smaller hawk that likes to land on the same branch - I'm thinking its a merlin) the crows waited till this hawk flew away then came in to investigate the perch while they actively chase off the smaller hawk.


San Jose Ca area - today (february)

thank you for your help!

Wow, two Coop vs. Sharpie posts in a row and no disagreement. I agree 100% coop on this one, and Sharpie on Julie's. These two posts make for a great comparison on the marks I look for. Look at how the feet on Julie's sharpie look delicate, even with respect to body size. Compare that with the somewhat meatier feet on this coop. Second, the head is larger and supraorbital ridge (aka brow) is more pronounced on the coop. On the sharpie, you see more of the smaller relative head and more of the eye. I often say coops look stern and sharpies look surprised. It is a bit of an exaggeration, but you can see the more wide eyed look of the sharpie in Julie's photo, and the sterner look here in Pat's coop.

The real clincher in almost all cases is size. Sharpies are quite small compared to coops. Of course, in photos scale is often hard to interpret. Pat gives a good description of the relative behavior of the crows towards the two different sized hawks, which also helps seal the ID as a coop. Pat, you are right this is not a juvi, but an adult. The red eye points to an older bird. Eye color by itself is not completely diagnostic of age, I have seen adult coops with yellow eyes, and late in their first year juvis eyes may be red but they have not molted to their adult plumage yet. The grey back and rufous breast are adult plumage. Juvis are more of a cinnamon color.

thank you all - and Isaac, I agree, your description of what you looked for is really helpful. I'm attaching a pic from the front of this bird, and agree that it seems to have more powerful (or meaty) looking feet than Julie's and definitely the stern look you mentioned.

I was just wondering, looking at Julie's bird, about the red eye/yellow eye - it is interesting if it is an age thing - the juvie cooper from my yard had more dull brown eyes (not especially red) ---

The eyes are generally related to age, but are unreliable because of variations in the population. I said "red" for adults, but I probably should have said "red/orange" because there is definitely a spectrum of colors in adults. Red is most common, at least here in SC. Generally, adults' eyes are more reddish, and juvis' are more yellowish, at least in accipiters. I looked at your other post, and would classify those eyes as being in the yellow/juvi side of the spectrum, which fits with the plumage. Red tails and red shoulders (and perhaps other buteos) are similar, except that the juvis have yellow eyes that turn to a brown, sometimes quite dark. Though generally the case, I have seen adult birds of all these species that have retained yellow eyes. Thus, plumage is a much more reliable way of aging. As an interesting side note, bald eagles are the opposite -- they start with dark eyes and they lighten as they mature over a few years.

Your new photo makes me think this might be last year's bird just molting into his adult plumage -- his grey head still shows signs of his juvi cinnamon color, and the variation in the length of his tail feathers indicate he might be molting. This could mean that his eyes will continue to redden as he ages, but that is by no means certain.