AT A GLANCE
- Common Name: Cooper’s Hawk
- Scientific Name: Accipiter cooperii
- Category: Birds
- Subcategory: Birds of Prey
- Size: Body length: 14.5–18.0 in (37–46 cm); Wingspan: 24.5–35.5 in (62–90 cm); Females are up to 30–40% larger than males
- Weight: Adult males: 7.8–14.5 oz (220–410 g); Adult females: 11.5–24.0 oz (330–680 g)
- Lifespan: 10–12 years in the wild; documented banding longevity exceeding 20 years
- Diet: Carnivore / Specialized avian predator (medium-sized songbirds including robins, jays, starlings, doves, pigeons, flickers, plus chipmunks and tree squirrels)
- Habitat: Mature woodland canopies and tree-lined suburban residential neighborhoods
- Range: North America from southern Canada through the United States to Mexico
- Conservation Status: Least Concern (IUCN Red List)
Overview
The Cooper’s Hawk (Accipiter cooperii), colloquially known among birders and falconers as the ‘big blue darter’ or ‘chicken hawk,’ is a fierce, medium-sized, and lightning-fast woodland bird of prey belonging to the accipiter family Accipitridae, native to North America. Renowned for its unparalleled aerial agility within dense forest timber, the adult Cooper’s hawk is recognized by its steely blue-gray back, black cap that contrasts with a lighter neck nape, warm reddish-brown barred breast, piercing ruby-red eyes, and long, rounded tail boldly banded in slate and pale gray with a prominent white terminal band.
In North American temperate forest, riparian, and suburban ecosystems, Cooper’s hawks function as dominant top-level avian mesopredators. By specializing in the capture of medium-sized songbirds and rodents, they exert powerful evolutionary pressure on prey populations, weeding out diseased individuals and preventing songbird over-concentration at localized foraging sites. Over recent decades, the species has executed a celebrated ecological adaptation, successfully colonizing urban and suburban residential greenbelts where backyard bird feeders provide high-density hunting grounds.
Biology and Physical Characteristics
Accipiter cooperii possesses aerodynamic and skeletal specializations engineered for high-speed navigation through dense, enclosed forest timber. Its wings are short and rounded, providing explosive initial takeoff thrust, while its exceptionally long, rudder-like tail acts as an aerodynamic airbrake that allows the hawk to bank at near-right angles around tree trunks at speeds exceeding 40 miles per hour (64 km/h). Its legs and toes are exceptionally long and slender, armed with needle-sharp curved talons; rather than killing with its bill, the hawk catches birds mid-flight and repeatedly squeezes its talons to induce fatal cardiac arrest or asphyxiation.
Behavior and Ecology
Cooper’s hawks are stealthy, ambush-oriented hunters that patrol forest edges using short, low-level flights beneath the canopy, utilizing fence lines, hedges, and buildings to screen their approach before launching an explosive, surprise pursuit. Mated pairs form monogamous bonds and perform sensational courtship displays, including synchronized sky-dances and slow, butterfly-like flapping flights over the forest canopy. They construct large stick nests high in the crotches of deciduous trees or pines, where females lay three to five pale blue eggs.
Conservation and Human Impact
Assessed as Least Concern by the IUCN Red List, Accipiter cooperii boasts a thriving, expanding continental population, representing a remarkable recovery from mid-20th-century population crashes caused by widespread agricultural organochlorine pesticides (DDT) that caused fatal eggshell thinning. Protected under the federal Migratory Bird Treaty Act, Cooper’s hawks have adapted seamlessly to suburban landscapes, demonstrating exceptional ecological resilience in modern human-altered environments.
Interesting Factoid
A Cooper’s hawk pursues prey through dense tree branches at 40 miles per hour so recklessly that bone studies reveal nearly a quarter of all wild adult Cooper’s hawks have healed fractures in their chest bones.