Fall. Accipiters. Confusion. It is that time of year when juvenile accipiters, in particular Cooper’s Hawk and Sharp-shinned Hawk, show up in our backyards and have us scratching our heads as to which species it is.
A year ago I put the above image up on facebook and asked which of the two accipiter’s it was – Cooper’s or Sharpie? The replies were overwhelmingly (and correctly) for Sharpie – “sharpie based on the structure and, especially, the slender legs”, ” slender tarsi, general structure and the patterning all say sharpie”, “not only are those shins sharp, but the belly streaking is heavier and extends further down than a Cooper’s.”
In the above composite image we can compare a juvenile Cooper’s Hawk (on the left) to a juvenile Sharp-shinned Hawk (on the right). When they are shown side by side, even though they are in slightly different postures, one can see differences, making it easier to work out which is which, rather than when viewing an individual bird.
- The eye looks larger and more foreward in the head on the smaller headed Sharpie.
- There is a noticeable dark stripe on the throat of the Cooper’s.
- The colour of the breast pattern – dark brown on the Cooper’s, and, warm brown on the Sharpie.
- The narrower and cleaner markings, tear drops thinning out on the belly, on a Cooper’s, versus, heavier or coarser and blurrier markings on the Sharpie.
- Broad barring on the flanks on the Sharpie.
- Thick sturdy legs (tarsi) on a Cooper’s while they are delicate and pencil-thin on a Sharpie.
- Though we can’t see the tail on the Cooper’s, it is usually rounded compared to the squared-off tail of a Sharpie. While that can be easier seen in flight, when posing upright one can see that on a Cooper’s, each tail feathers get shorter towards the outer feather. This gives it a rounded look when it is spread in flight.
By going through these pointers as you study the bird, you should be able to feel confident in your identification of the next juvenile accipiter that challenges you!