The black falcon (Falco subniger) is a medium-large falcon that is endemic to Australia. It can be found in all mainland states and territories and yet is regarded as Australia's most under-studied falcon. Description The information in this section is based on recent descriptions by several authors (notably, Debus & Davies 2012, Debus & Olsen 2011, Morcombe 2002 and Birds in Backyards n.d.). Size (adult, beak to tail): 45 – 56 cm (average 50 cm), tail makes up about half the length. Note: Females are larger than males - this is a form of sexual dimorphism. Average weight: 833 g (female) 582 g (male). Wing span: 95 –115 cm. Colouration is uniform dark brown to sooty black; juveniles are generally darker than adults; underwing feathers are two-tone (flight feathers slightly paler); adults may have an evident dark stripe below the eye. Occasionally the birds may have a white chin, spots on underwing coverts or bars on undertail coverts. Cere, eye ring and feet are pale grey (or pale blue-grey); eye is dark brown and beak tip is black. Talons are black. Chick is white down. The falcon's body is streamlined with a relatively long tail and slim build. Wings are long and pointed tapering toward wing tip. Notes on identification When attempting to identify a flying raptor Debus & Davies recommend concentrating on the bird's silhouette (including shape of wings and proportions), flight style and vocalisations, rather than on details of colouration. Australian falcons can be differentiated from hawks by their toothed upper mandible (with a corresponding notch in their lower mandible) and by their long pointed wings. Brown falcons (Falco berigora) are a common and widespread species in Australia, and they are the most likely to be confused with the black falcon (particularly brown falcon juveniles and black morphs). In fact, Debus & Olsen suggest many observations and behaviour of brown falcons have mistakenly been attributed to the black falcon, due to incorrect identification. The two species differ in the relative length of exposed tarsi (the lower, visible half of the bird's leg) compared with thigh feathers, flight style, wing attitude, and bold underwing barring and tail barring (which appear on the brown falcon only). Taxonomy The black falcon belongs to the family Falconidae, as do the other three falcon species which are found in Australia, the brown falcon, grey falcon (Falco hypoleucos) and peregrine falcon (F. peregrinus). Genetic