Cooper’s hawks (Accipiter cooperii) and sharp-shinned hawks (Accipiter striatus) are two of the most easily confused raptors in North America. These accipiters are found practically throughout America, with the smaller sharp-shinned hawk migrating as far north as Alaska for the summer.
Both species have adapted to urban and suburban environments, and you may be lucky (or unlucky) enough to spot one of these expert bird hunters in your own backyard. So let's get into it, how do you tell the difference between Cooper's hawks and Sharp-shinned hawks?
Cooper’s hawks are much larger than sharp-shinned hawks, and have proportionately larger dark capped heads, rather than the small dark hooded head of the ‘sharpie’. In flight, the larger head and rounded tail tip (rather than square) is a good marker for cooper’s hawks.
Distinguishing between cooper’s hawks and sharp-shinned hawks out in the field is tough, so don’t be too hard on yourself if you can’t make a positive identification every time. The best strategy is to look for multiple clues, rather than just focusing on differences like their size.
Read on for a complete guide on distinguishing between these two easily confused American accipiters.
Cooper's hawks are significantly larger than sharp-shinned hawks, although this isn’t always easy to notice out in the field. As a rough indication, Cooper's hawks are about the size of a crow while sharp-shinned hawks are closer to the size of a mourning dove.
The females of both Cooper’s and sharp-shinned hawks are significantly larger than the males. This makes distinguishing between the two species based on size alone pretty unreliable. This is because a female sharp-shinned hawk is close to the size of a male Cooper’s hawk. Size alone isn't always an easy way to distinguish between the two species, but it is a useful clue.
Continue reading to learn about more important differences between Cooper’s and sharp-shinned hawks.
Cooper's Hawk in flight
There were an estimated 800,000 individual Cooper’s hawks in America and Canada between 2005 and 2014. Sharp-shinned hawk numbers were estimated at 583,000 across the United States and Canada, but this elusive species is notoriously difficult to count.
Both cooper’s and sharp-shinned hawks are very widely distributed across North America. Cooper's hawks are resident across most of the lower 48 states, but they are only present during the summer breeding season in the far north and overwinter in the central states.
The sharp-shinned hawk ranges further north, all the way to Alaska. This species is more migratory than the Cooper’s hawk, although they are present all year round in the west and the east of the United States.
Immature Sharp-shinned hawk in flight
It is best to use a variety of markers to tell a Cooper’s hawk from a sharp-shinned hawk, rather than to rely on any single feature.
Continue reading to learn some of the most important differences between these widespread American accipiters.
Close up of a Cooper's Hawk
Close up of a Sharp-shinned Hawk
The tip of the tail provides another good way to tell these two similar hawks apart. The tail tip is square in the sharp-shinned hawk and slightly notched in the center. Cooper’s hawks have a more rounded profile. This difference in tail shape is most visible when the birds are in flight.
Wing shape is another helpful characteristic for distinguishing Cooper’s hawks from sharp-shinned hawks. When seen from below in flight, the edges of the wings are relatively straight in Cooper’s hawks. The wings of sharp-shinned hawks appear to project forward, creating a curved profile on both the leading and trailing edge.
Cooper's Hawk flying with a songbird
Both species are specialized bird hunters, although they will also take small mammals and insects. The Cooper's hawk diet consists mostly of medium-sized songbirds like blackbirds and American robins. They are capable of taking birds up to the size of ruffed grouse and American crows, and mammals as large as hares, however.
Sharp-shinned hawks tend to feed on smaller birds like sparrows and juncos. They are powerful hunters too, of course, and are capable of taking birds like ruffed grouse which are much larger than themselves.
Neither Cooper’s nor sharp-shinned hawks produce any songs, but they can be told apart by their calls. Sharp-shinned hawks have a higher-pitched call that is best described as kik-kik-kik. Cooper’s hawks produce a similar call, but it is better described as cak-cak-cak.
These calls are mostly heard during the breeding season, and the birds are generally silent for the rest of the year.
Sharp-shinned Hawk perched high up in a tree
The oldest recorded Cooper’s hawk was 20 years old when it died, although records have shown that these birds live just 16 months or so after being banded on average. The oldest recorded sharp-shinned hawk was 13 years old, indicating that this species probably has a shorter lifespan than its larger relative.
Apart from the obvious difference in size, the females of both Cooper’s hawks and sharp-shinned hawks closely resemble the males. This means birdwatchers should look for the characteristic differences in nape coloration, tail shape, and head size to make a good identification.
The females of both Cooper’s and sharp-shinned hawks are significantly larger than the males. This sexual dimorphism is typical of raptors, but the accipiters take it to extremes. Females of these hawks can be as much as 30% larger than their partners.
The jury is still out on exactly why this is the case, but it could be to minimize competition for prey items or to better equip females for defending their nests. Another benefit of the size difference is that since males focus on smaller prey, they also bring manageable meals to the chicks.
Cooper's Hawk in a tree with prey
Juveniles of both Cooper’s and sharp-shinned hawks look quite distinct from adults. Unfortunately, they also look quite similar to each other, making identification difficult.
The juveniles of both hawk species have brown backs rather than the blue-gray color of the adults. Their underparts are white, with bold brown teardrop-shaped markings from the breast to the belly.
The brown streaks on the underside of the sharp-shinned hawk tend to be bolder than those of immature Cooper’s hawks. Young sharp-shinned hawks also have a distinct white eyebrow stripe, which is a great marker to look for if you get a good look at the bird.
An immature Sharp-shinned hawk, perched on a post
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