The key to identifying Cooper’s hawks and sharp-shinned hawks is to remember that there is no single telltale characteristic that can identify either species. Instead, birders need to consider several characteristics of the bird to decide which species it is, and even then the conclusion may not be positive. By studying these characteristics closely, however, birders can become more confident with their accipiter identifications.
Identification Characteristics
When trying to identify Cooper’s hawks and sharp-shinned hawks, watch for these key traits:
Size: The bird’s size is the best indicator of its species. A sharp-shinned hawk is smaller and averages 10-14 inches in length, roughly the size of a jay or dove. The Cooper’s hawk is larger, with an average size of 15-20 inches, closer to the size of a crow. A small male Cooper’s hawk, however, can be difficult to tell from a large female sharp-shinned hawk on size alone. To judge a bird’s size more accurately, compare it to nearby objects that can be measured, such as fence posts, tree branches, or bird feeders. Body Proportion: The general shape of a bird can also be a clue to its identity. A sharp-shinned hawk has a heavy-shouldered appearance with much narrower hips, giving it an inverted triangle shape. A Cooper’s hawk has a more even distribution of girth and may seem barrel-shaped. Posture and viewing angle can influence what proportions look like, however, so watch the bird carefully and observe it from different angles if possible for a good overall perspective. Head: Sharp-shinned hawks have proportionally small heads and may look stunted, while Cooper’s hawks have a distinctly larger, more prominent head. A Cooper’s hawk may also raise the feathers on its crown and could appear to have a small crest or a corner on the back of its head, giving it a more aggressive appearance. Nape of Neck: If you can see the back of the bird, check the nape of its neck. A sharp-shinned hawk will appear to be the same color from the back to the top of the head, while a Cooper’s hawk will have a paler nape with a contrasting darker cap on the head and darker plumage lower on the back. Neck Length: A sharp-shinned hawk may appear to have no neck at all or just a very short neck. Cooper’s hawks have a longer neck and tend to be more active with head movements. Front Coloration: Both birds are heavily barred with rufous coloring through the chest and abdomen, but a sharp-shinned hawk can have thicker streaks on the lower abdomen while a Cooper’s hawk may be slightly paler closer to the legs. This is also most prominent on juvenile birds when the Cooper’s hawk will be much paler below and its streaking will be more brown than red. Legs: The sharp-shinned hawk gets its name from its pencil-thin legs that give it a longer-legged appearance. A Cooper’s hawk’s legs are thicker, approximately the width of a finger, and it may appear to have shorter legs overall. Tail: When perched, a sharp-shinned hawk has a shorter tail that looks square with sharp corners and a small central notch. A perched Cooper’s hawk will have a much longer tail that is rounded and lacks the notch. Cooper’s hawks also have a broader white tip at the end of the tail while sharp-shinned hawks only have a very narrow white tip, but this can be difficult to see, especially if the feathers are older and the tip may be worn down. Flight: Accipiters can be challenging to identify in flight, particularly because they dart and dive very agilely after prey. When gliding or soaring, however, a sharp-shinned hawk holds its wings pushed forward at the wrist and the head may not extend past the wings. A Cooper’s hawk will hold its wings straighter and the head is more prominent. Sharp-shinned hawks also have more erratic wing beats, while a Cooper’s hawk’s wing beats are somewhat slower. Prey: If you are fortunate enough to see what these raptors eat, you may have a great clue as to what species the accipiter is. Sharp-shinned hawks eat almost exclusively small birds such as sparrows and finches, while Cooper’s hawks generally take larger birds such as doves. Cooper’s hawks may also regularly take small rodents and mammals, though this is rare (but not unheard of) for sharp-shinned hawks. Behavior: The behavior of a bird can offer clues to its identity. Both of these accipiters may ambush prey by flying nearby, or they may perch and wait for unwary prey to approach. Sharp-shinned hawks, however, prefer to perch in trees or bushes, while Cooper’s hawks will perch frequently on poles or fences. Range: Unfortunately for identification purposes, both types of hawks overlap almost completely in their range. Sharp-shinned hawks, however, can be found further north and south, even as far as Alaska and Central America, and they are much more common in yards and gardens than Cooper’s hawks.
Accipiter Identification Tips
When a hawk visits your yard, you may only have a few moments to successfully identify the species. For sharp-shinned and Cooper’s hawks, focus on the bird’s size, the size of the head, the size of the legs, and the length of the tail for the most valuable field marks, but don’t jump to conclusions based on only one or two marks or a very brief sighting. Instead, enjoy the challenge of identifying a hawk and use every observation opportunity as another chance to practice distinguishing between these two confusing species. With time, practice, and persistence, you will soon be able to identify nearly any accipiter. Cooper’s and Sharp-Shinned Hawk Quick Reference
