Published first in March 2017
and updated several times up to April 2024.

One of the great natural mysteries for me is how two species (sometimes more) can evolve to look so similar and yet not be an offshoot of the other. Take Cooper’s and Sharp-shinned Hawks, for example. If I see one or the other in the wild,
I really can’t be sure which it is, even though I’m familiar with many of the indicators that pros use to differentiate them.
I’m not alone!

For what the Cornell Lab of Ornithology tells us look for,
go to their website. The images are NOT very good,
but the table summarizing the differences is helpful.
Click on items in their list for extra illustrations / details: Cooper’s vs Sharpies – Cornell

And from  another site  (info seems no longer visible unfortunately, comparative images copied below):

I’ve edited, for improved clarity, the description from Notes from the Wildside below:
“In the above composite image we can compare a juvenile Cooper’s Hawk ( left) with a juvenile Sharp-shinned Hawk (right).
When they are shown side by side, it easier to work out which is which, even though they are in slightly different postures.

• The eye looks larger and more foreward in the head on the smaller headed Sharpie.
  NOTE: CORNELL’S SITE SAYS THE OPPOSITE! “Eyes appear to be close to half way between front and back of head [of the Sharpie].” Just keeping life interesting….
  [To this, I’d add, from the Cornell site, that a Cooper’s head seems larger and less rounded than a Sharpie’s, and that the Cooper’s head appears ‘capped’ while the Sharpie’s appears ‘hooded’ with a shadowy patch down the nape. This may not be obvious with juvies, however….]
•  The Cooper’s head is typically less ‘tucked in’ than a Sharpie’s. There is a noticeable dark stripe on the throat of the Cooper’s.
• The breast pattern is ‘ dark brown’ on the Cooper’s, and, ‘warm brown’ on the Sharpie.
• Cooper’s display narrower and cleaner tear drop markings,  thinning out on the belly,
  whereas the Sharpie has heavier, or coarser,  ‘blurrier’ markings.
• On the Sharpie Broad note the broad barring on the flanks.
• Cooper’s  have thick sturdy legs (tarsi),  while Sharpies’  are delicate and pencil-thin.
• Though we can’t see the tail on the Cooper’s in this image, it is usually rounded compared to the Sharpies’ squared-off tail. While tail shape can be easier seen in flight, when posing upright with the tail fanned, a Cooper’s tail feathers get shorter towards the outer feather” giving it a rounded look when spread in flight.” (edited by KAR from the Wildside)

So what’s the one below, then?

This one has my Flickr friends giving me opposing labels. I think it’s an adult Cooper’s, but I’m still not sure….

From these lists, items that are easiest to examine are tail feathers, eye position, and head shape and cap, and in juveniles, breast markings. Size, it turns out, isn’t very reliable, as male Cooper’s are relatively small and female Sharpies are relatively large, so even though we know that Sharpies are generally noticeably smaller than Coops when comparing the same gender, it’s a problem when we can’t be sure which gender we’re looking at, and there’s no reliable way in the field to differentiate the males from their mates.

So, even knowing a few identifiers, I often have to wait until I get home and look at the images to make my guess — and then wait until after I’ve posted and real experts weigh in….

Sharpies range through more of Canada than Cooper’s do. Despite their larger range, it seems that there are more Cooper’s in total for the continent than their smaller lookalikes.   Click either image below to enlarge it.

Cooper’s range – CLoO

Sharp-shinned range – CLoO

It’s always exciting for most of us to come across either species. While not rare, they’re not a bird that I can expect to see on a regular basis, or at least, they weren’t until I moved to Kelowna. Here, their territories are a little easier for me to pin down than they were at The Coast. This winter, J L Cummins, a birder-photog colleague in Washington State, has enjoyed having a Sharpie in his backyard, and it has become as familiar to him as Kessie, the female American Kestrel has become for me. Perhaps the Cooper’s / Sharp-shinned that I observed  several times each winter and spring in our neighbourhood will become as identifiable as Jim’s…. (Update 2024: I haven’t seen either species in the neighbourhood for the past two years!)

So, I’ll wrap up this discussion of uncertainty with some photos taken in the neighbourhood:

The photo, below, of an adult bird has been identified by expert friends as a Cooper’s. To me it seemed large enough, and the tail is rounded, but I see a hood, not a cap on its rounded head and nape, which are more indicative of a Sharpie!

In January 2017 I had a great but unexpected opportunity to photograph the hawk below. Sadly, my camera settings were right for a previous photo I’d taken of a distant Red-Tail, and woefully wrong for this guy/gal. Surprisingly, when I posted it on Flickr anyway, it got far more hits and positive comments than it deserves. It’s here simply because, at the time, I promised myself that if I got another chance, I’d do much better…. See the next one….

So  finally, on March 8, 2017, I did get my “another chance.” Guided by instinct, at about 10 AM I entered Belmont Park from the east so I’d have the light behind me. The Park was extremely quiet, as it often is when there’s a hawk about. Just after I passed a small fir on my left, I heard a flapping of wings and figured I’d flushed one of the Mourning Doves that frequents the area. Then I saw the hawk as it veered to perch on a pine about 20 meters ahead of me. I got the shot, and, right or not, am calling it a Sharp-shinned, based largely on the one shot of the tail and the two shots of the head and nape.
Click on any of the photos to enlarge it.

Sharp-shinned with Quail breakfast – 1

Sharp-shinned with Quail breakfast – 2

Sharp-shinned with Quail breakfast – 3

Hope you got this far and that you enjoyed looking at these powerful and handsome hawks!

• Birds
• Raptors