Cooper’s Hawk Species Notes, Development Photos and Case Histories

Cooper’s Hawks are medium-sized hawks usually found in wooded areas, although they are becoming increasingly common in urban and suburban areas.  They appear to be highly adaptable to changes in their environment.  Their short, rounded wings and long tail make them  highly maneuverable in dense woods, and their ability to accelerate quickly gives them the ability to capture songbirds in flight.  They also eat small mammals such as chipmunks.   Cooper’s Hawks are relatively late nesters, and juveniles are commonly seen in Alabama in late May and June.  Incubation is usually 34-36 days, and nestlings are brooded by the mother for the first two weeks.  Birds are fully self-feeding by 18 to 21 days.  Males develop more rapidly than the much larger females, and usually become  branchers by 26 days after hatching, although females do not leave the nest until 3 to 4 days later. Young remain together near nest for 5 to 6 weeks after fledging. Parents continue to feed the juveniles at a steadily decreasing rate for approximately 7 weeks.

This swift, bird-eating hawk presents special challenges for the wildlife rehabilitator.  Their demanding hunting style requires pinpoint accuracy and the ability to accelerate rapidly and to maneuver through dense brush with maximum agility.  These are skills that cannot be developed adequately in a flight cage, so the best alternatives for raising young birds of this kind are hacking, reuniting, or fostering the young to a wild nest.  I have successfully hacked a brood of four young Cooper’s Hawks that were young nestlings when orphaned.  Hacking older juveniles within a day or two of fledging is less likely to be successful, since they must spend enough time on the hack platform before fledging to recognize it as a dependable source of food after fledging. Single juveniles are also poor candidates for hacking, as they will be deprived of normal social conditioning. Reuniting and fostering are usually the best alternatives, especially for older nestlings that are close to becoming branchers.  Fortunately, Cooper’s Hawks take well to laundry basket nests, and will respond immediately if the recorded alarm calls of the juvenile are used.  My recommendation would be to do everything you can to reunite or foster any juvenile Cooper’s Hawk that you receive.

 

Cooper’s Hawk (Accipiter Cooperii)

Development Photos

Young Nestlings

 

Older Nestling

 

Brancher

 

Fledgling

 

Case Histories

Case #1

Case #2

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