ABSTRACT
The family Accipitridae is a group of raptors that are apex predators in the avian world. Although superficially similar to falcons (Falconidae), these two families are apparently not closely related. In addition to genetic evidence, they have different bill structures, contour feather shapes, and flight feather molting sequences. Specifically, Accipitridae lack a "tooth" along the maxilla present in Falconidae, have more rounded contour feathers, and follow a more typical molt sequence. Accipitridae follow a Complex Basic Strategy, usually with an inserted limited preformative molt, but in some individuals this may be absent. In larger species, definitive prebasic molts can be incomplete and/or follow Staffelmauser, taking up to 4 years to replace all juvenile flight feathers. Brood patches occur in females, but also less extensively in males for some species. In some species, there can be two or even three distinct color morphs, which, in addition to individual and age-specific variation, can create substantial identification challenges.
