Cooper’s hawks and sharp-shinned hawks are two very similar-looking bird species that can be challenging to distinguish between. Both are small, forest-dwelling hawks with short, rounded wings and long tails that help them maneuver nimbly through dense vegetation. Telling them apart requires careful observation of several key field marks relating to size, proportions, plumage patterns, and behavior. With practice, birders can learn to reliably separate these two raptors, even during brief glimpses.
Size Difference
The most reliable way to distinguish a Cooper’s hawk from a sharp-shinned hawk is by size, as Cooper’s are noticeably larger on average. Sharp-shinned hawks measure around 9-11 inches long with a wingspan of 17-21 inches. They weigh between 4-8 ounces. Cooper’s hawks are larger at 14-20 inches long, with a wingspan of 24-35 inches and weight between 7-24 ounces.
When seen together, the size difference is obvious. When viewed alone, judging proportions can help determine the species. Cooper’s hawks have a larger, broader-looking head and fuller chest compared to the smaller sharp-shinned. Their wings appear shorter and broader, with a bulging wrist when folded. Overall, Cooper’s give the impression of being more muscular and robust. Sharp-shinned seem more slender and delicate.
Plumage Patterns
Plumage differences provide another useful clue. Adult Cooper’s hawks generally have a black cap and pale nape, while sharp-shinned lack the contrasting pale nape patch. The breast of Cooper’s is coarsely barred reddish-brown, versus fine reddish barring on a sharp-shinned.
Sharp-shinned tails have more narrow white bands. Their wings are patterned with thin reddish barring, while Cooper’s have thicker brown barring on the upperside. The pale underside of the flight feathers is also more conspicuous on sharps.
Juvenile plumages are harder to distinguish, but Cooper’s still tend to show chunkier streaking on the underparts and a more solid cap. Sharp-shinned juveniles have finer streaking below and retain some of the adult’s thin, red wing barring.
Feature | Cooper’s Hawk | Sharp-shinned Hawk |
---|---|---|
Size | 14-20 inches long 24-35 inch wingspan 7-24 oz weight |
9-11 inches long 17-21 inch wingspan 4-8 oz weight |
Plumage | Boldly barred rufous underparts Black cap and pale nape Thick brown barring on wings |
Finely barred underparts Lacks pale nape Thin red barring on wings |
Tail | Broad white tail bands | Narrow white tail bands |
Behavior and Flight Style
Differences in flight style and hunting behavior can also help in identification. Sharp-shinned hawks often hunt smaller bird prey in dense cover, pursuing with fast, maneuverable flight through tangled vegetation. They frequently perch inconspicuously inside trees and bushes.
Cooper’s more often ambush larger prey items from an open perch, making short stoops on birds up to pigeon size. Their flight style is steadier and less acrobatic compared to the sharp-shinned’s expert dodging. Cooper’s are likely to perch openly on poles, wires and fence posts.
Habitat
Cooper’s and sharp-shinned hawks occupy similar woodland habitats. However, Cooper’s are more adaptable and also utilize open woodlands, scrub, and urban areas. Sharp-shinned are more strictly forest-interior birds, preferring continuous tracts of boreal, deciduous, or mixed forest. During migration, Cooper’s are more widespread while sharp-shinned concentrate along the coasts.
Vocalizations
While their alarm calls are very similar, Cooper’s hawks give a loud “kak kak kak” compared to the sharper “kek kek” of a sharp-shinned. With practice an attentive birder can distinguish them. However, visual differences remain more reliable for identification in most cases.
Range and Distribution
Cooper’s and sharp-shinned hawks broadly overlap across much of North America. However, some key differences in range can aid identification regionally:
- In western mountains, sharp-shinned are more widespread while Cooper’s are scarce.
- Throughout Mexico, Central America, and the Caribbean, only the Cooper’s hawk occurs.
- In South America, only sharp-shinned are present.
Where their breeding ranges meet in southern Canada, distinguishing nest sites can help. Cooper’s build larger nests, often in pines or hardwood trees closer to open areas. Sharp-shinned nests are smaller, in dense conifers, and near water.
Conclusion
Telling apart Cooper’s and sharp-shinned hawks requires a close look at size, proportions, plumage patterns, behavior, habitat, and distribution. With practice, most birders can learn to identify these species reliably, even during quick encounters. If you can get a decent look, size differences are usually the best clue – Cooper’s simply look more robust and broad-chested. Plumage and behavioral differences provide additional support. Familiarity with the species’ habitats, ranges, and voices can also aid identification.
Key Identification Points
- Cooper’s are noticeably larger with a stouter, broader-chested profile.
- Adults show plumage differences like Cooper’s boldly barred underparts and pale nape.
- Cooper’s show steadier, less acrobatic flight on broader wings.
- Cooper’s take prey from open perches, Sharp-shinned hunt within forests.
- Cooper’s are vocalizing “kak kak”, Sharp-shinned give a “kek kek”.
- Ranges differ, with Cooper’s more widespread in Mexico and the Caribbean.
With a good view and by noting several features, experienced birders can confidently separate these two woodland hawk species. Less experienced birders may need to settle with a more general category like “small accipiter” in difficult cases. But knowledge of the key differences and field experience will lead to improved identification skills over time.
Cooper’s and sharp-shinned hawks are fascinating raptors for any birder to see. Learning to identify them expands your skills and helps in understanding their roles in woodland ecosystems. Sharp identification not only aids your personal bird lists, but contributes valuable data to bird monitoring and conservation efforts. So take the time to carefully observe size, shape, plumage, behavior, habitat, and any other clues that can help distinguish these two similar hawks. Your efforts will be rewarded as your abilities to confidently tell Cooper’s from sharp-shinned grows.
Further Reading
For more in-depth identification tips and photos, consult these excellent guides:
- The Crossley ID Guide: Raptors
- Hawks at a Distance: Identification of Migrant Raptors
- Peterson Field Guide to Hawks of North America
- The Sibley Guide to Birds
Online resources like All About Birds and The Cornell Lab of Ornithology also provide photos, recordings, and more information to aid identification of Cooper’s and sharp-shinned hawks. Pairing the use of field guides with time spent observing these birds in the wild will rapidly improve your skills in distinguishing between them.