Cooper's Hawk
Kingdom: Animalia, Phylum: Chordata, Class: Aves, Order: Accipitriformes, Family: Accipitridae, Genus: Accipiter, Species: Accipiter cooperii · Accipitridae (Hawks, Eagles, and Kites) · Primary flight feather (remex); likely an outer primary (P7-P9) due to the strong asymmetry and emargination.
Species
Accipiter cooperii
Feather Type
Primary flight feather (remex); likely an outer primary (P7-P9) due to the strong asymmetry and emargination.
Family
Accipitridae (Hawks, Eagles, and Kites)
Shape
Highly asymmetrical with a very narrow leading edge (outer vane) and a broad trailing edge (inner vane). The tip is rounded, and there is a distinct notch (emargination) on the trailing edge near the distal end.
Size
Estimated at approximately 7.5 to 8.5 inches (19-22 cm) in length, which is consistent with the primary feathers of a female Cooper's Hawk (females are significantly larger than males).
Rarity
Common
Color & Pattern
Dusky brownish-grey on the dorsal surface with a series of dark, distinct chocolate-brown transverse bands (bars). The underside is paler (silvery-grey) with more muted versions of the bands. The rachis is dark on top and light underneath.
Barb Structure
Densely pennaceous and tightly interlocked for aerodynamic integrity; the base shows a small amount of plumulaceous (downy) barbs for insulation. The barbs are stiff and well-interlocked.
Texture & Surface
Stiff and smooth with a firm, slightly glossy finish on the dorsal side. The trailing edge feels softer than the rigid leading edge, which is designed to cut through the air.
Description
A medium-sized hawk designed for high-speed chases through dense vegetation. Adults have blue-gray backs and rufous-barred underparts, while juveniles are brown with vertical streaks. This primary feather is the aerodynamic powerhouse of the species, allowing for the sudden bursts of speed and sharp turns characteristic of accipiters.
Key Features
Distinctive dark horizontal banding across a greyish-brown background, strong asymmetry with a narrow outer vane, and a notched inner vane characteristic of raptor primaries.
Habitat
Woodlands, forest edges, and increasingly common in leafy suburban areas and urban parks where bird feeders attract their prey.
Geographic Range
Common across North America, ranging from Southern Canada through the United States to Central Mexico. Northern populations are migratory, while southern birds are often year-round residents.
Condition Notes
Good condition. There is some minor separation of the barbs (splitting) near the base and mid-vane, likely due to natural wear or 'molt-drop' handling. No significant fault bars or parasitic damage visible.
Interesting Facts
Cooper's Hawks are 'stealth hunters.' They often fly low to the ground, using bushes and buildings as cover to surprise smaller birds. They were once heavily persecuted as 'chicken hawks' but have adapted remarkably well to human environments.
Ecological Role
Apex avian predator, specializing in hunting medium-sized birds (like pigeons and jays) and small mammals. They serve as a vital control on bird populations and are indicators of healthy woodland and suburban ecosystems.
Similar Species
Sharp-shinned Hawk (Accipiter striatus) feathers are much smaller and more delicate. Red-shouldered Hawk (Buteo lineatus) feathers have higher contrast black-and-white banding.