Sharp-shinned (Accipiter striatus) and Cooper’s (Accipiter cooperii) hawks commonly prey on feeder birds, and they are frequently reported by FeederWatchers. Despite their common occurrence, these hawks present a significant identification problem for many beginning and intermediate (and even more advanced!) birders. There is great variation in plumage and in size for these two species. Therefore, perhaps more than any other similar-looking birds, no single field mark is likely to distinguish one species from the other. Instead, the careful observer must use a combination of field marks and draw from the overall "gestalt" of the hawk for proper identification. No field guide will substitute for plenty of practice in the field.

If you observed one of these two hawks during a FeederWatch count and you ar not absolutely certain of the hawk's identification, please report the bird as an "Accipiter sp." (the genus in which these two species are classified). You may need to add this species name to your list using the Add a Species function. If you need assistance, contact FeederWatch staff.

Adult birds

Adult Sharp-shinned Hawks and Cooper's Hawks have dark gray backs, rusty-barring on the breast, and red eyes.

Similar in size to a jay or dove (avg. 10-14" long. Female is larger and can appear nearly as large as a male Cooper's Hawk.

Tip of long tail is typically square, showing prominent corners. The outer tail feathers are usually the longest (or nearly so). Note: tail tip of soaring bird appears rounded.

Tail has narrow white tip.

Head appears small compared to body.

Similar in size to a crow (avg.14-20" long). Male is smaller and can appear nearly as small as a female Sharp-shinned Hawk.

In fresh fall plumage, its long tail is usually rounded at the tip. The middle tail feathers are usually the longest.

Tail typically has wide white tip, although the white can wear off over time.

Head appears large compared to body.

The feathers on the crown and the back of the neck are dark, giving the bird a "hooded" appearance.

The feathers on the crown are darker than the feathers on the back of neck, giving the bird a "capped" appearance. The feathers on the back of the head are often raised, giving the bird a crested look.

Eyes appear to be close to half way between front and back of head.

Broad chest and narrow hips. Center of gravity is often high.

Thinner, pencil-like legs that can look long when compared to Cooper's.

Eyes appear to be close to the front of the head.

Thick, tubular body with a lower center of gravity.

Thicker, shorter looking legs compared to Sharp-shinned.

When the bird is soaring, short rounded wings are pushed forward at the wrists so that the small head barely extends past the wings.

Typically flies with several quick wingbeats followed by a short glide. The wing beasts can be erratic and more difficult to count than for a Cooper's.

The large, angular head projects far beyond the wings when soaring, giving the bird a cross-like appearance.

Often flies with slower wing beats followed by a short glide. The slower, regular wing beats are easily counted when the bird flies overhead.

Identification tips

There are lots of field marks to distinguish these hawks, although some are judgment calls (such as size) and some require a certain perspective (front or back of bird). The best way to distinguish Sharp-shinned from Cooper's hawks is to try to gather as many field marks as possible. Here are some key field marks to look for first:

• With all plumages, Cooper's Hawks are barrel shaped, with the width of the chest fairly close in size to the width of the hips and the largest portion of the chest about halfway down the body. Sharp-shinned Hawks, on the other hand, are widest at the shoulder and get distinctly narrower down to the hips.
  
  
• The size of the head relative to the body can be a reliable field mark. It isn't always easy to see, and hawks hold their heads in different positions that can affect how big the head looks, but usually a Sharp-shinned Hawk's head looks small, and a Cooper's Hawk's head looks large. Sharp-shinned Hawks appear short-necked; Cooper's Hawks appear tall.
  
  
• Cooper's Hawks are larger than Sharp-shinned Hawks, but size can be difficult to judge if you see the bird in isolation, and there is wide variability in size from one individual to the next and between larger females and smaller males in both species. Furthermore, large female Sharp-shinned Hawks can be nearly as large as small male Cooper's Hawks. Generally, however, size can be a reliable field mark, especially if the bird is very large or very small.
  
  
• If you can see the front of the hawk and it is a juvenile hawk, the thickness and color of vertical streaks is fairly reliable. As can be seen on the bottom of the Accipiter Photo Gallery page, there is some overlap between the species, but this is pretty unusual. Very thick, rufous stripes that extend down the lower belly are a good indication of Sharp-shinned Hawk, and very thin, dark streaks that fade away on the lower belly are a good indication of Cooper's Hawk.
  
  
• Differences in leg size can be helpful for distinguishing between the hawks. Very thin legs are diagnostic for Sharp-shinned, and very thick legs are diagnostic for Cooper's Hawk. This field mark requires some judgment, though, and sometimes it is hard to tell if the legs are thick or thin.
  
  
• If you can see the back of the hawk, and it is an adult, then the color of the nape is a reliable field mark. Cooper's Hawks have a pale nape with a clear contrast to a dark cap. Juveniles of both species can show a pale nape, however.
  
  
• The rounded versus square tail is reliable if you can see all the tail feathers and they are held straight. The tail feathers of Sharp-shinned Hawks are the same length, whereas the outer tail feathers are shorter than the inner feathers on Cooper's Hawks. However, when seen from the back, if a Cooper's Hawk holds it's tail tightly closed, the longer feathers can completely block the shorter feathers from view, making the tail look square. Furthermore, a Sharp-shinned Hawk's tail can look rounded if the feathers are spread. New feathers growing in can further complicate the issue.

More identification tips and challenges can be seen on the Accipiter Photo Gallery page.

Did you know?

FeederWatch data shows that accipiters, especially Cooper's Hawks, are becoming more common around feeder areas. Other researchers have found that fewer Sharp-shinned and Cooper's hawks are migrating based on lower counts at various hawk watches. It appears that fewer of these hawks are migrating, which could be related to climate change or because they have learned that they can survive year round if they find a good feeder area to patrol. See trend graphs for the Sharp-shinned Hawk and the Cooper's Hawk, which show the changes reported by FeederWatchers over time. If you have not participated in Project FeederWatch, join today and report the birds that visit your feeders in winter.

Additional resources

Visit the Lab's All About Birds web site to find species accounts for Sharp-shinned Hawk and Cooper's Hawk that detail the range, habitat, and calls for each species.

Resources from Birds in Forested Landscapes: Sharp-shinned Hawk, Cooper's Hawk, Identifying Hawks

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