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Falcon species

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.

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.

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 analysis has revealed that the black falcon may be an early offshoot of the Old World hierofalcons such as the saker falcon (F. cherrug) and laggar falcon (F. jugger).

The black falcon is listed by the IUCN as least concern. In 2009 BirdLife International estimated the black falcon's population as between 670 and 6700 mature individuals, with a stable population trend.

The black falcon is widely distributed across mainland Australia, except densely forested areas. The species is only occasionally seen in the southern interior of WA and is sparse in coastal areas of south eastern Australia.

The falcon's flight has been described as variable. Generally it flies with relaxed ‘crow like’ wingbeats with occasional soaring. It also flies with a stiffer, shorter wingbeat. It glides and soars with slightly drooped or sometimes horizontal wings, carpals forward (wings are stretched out straight when gliding). Tail is normally folded (except when soaring, when it is fanned with notched corners). It often soars for long periods without flapping and catches prey in the air or on the ground. In pursuit of prey it uses powerful, rapid wingbeats. While resting the bird's wing tips are shorter than the tail and legs appear short. The species preys upon and is sometimes the prey of other raptors.

The black falcon's diet primarily consists of bird species, from finch to cockatoo size but they have also been observed feeding on small mammals (i. e. rabbits, mice and rats), insects and carrion. Nest sites may be a limiting factor for black falcons, specifically where there has large scale vegetation clearing, such as occurred in the sheep wheat belt of NSW.

The most common call is similar to the 'cackle' of the peregrine falcon but is slower and deeper – The guttural call is shorter and more rapid when being attacked or when intruders are nearby –
The species also faces competition from corvids and other raptors over nest sites and possibly prey. Disturbance of nest sites and harassment by other birds (including cockatoos) also appears to impact the falcon's breeding success. Victoria does not appear to have a recovery plan in place for the black falcon.