Australian Bush Birds
Black Falcon  -  Falco subniger
Black Falcon
Black Falcon on a typical vantage point in semi-arid country near Quilpie, south-western Queensland.
Black Falcon Head of Black Falcon with blue eye-rings and blue-grey bill.
map map The Black Falcon - Falco subniger - is uniformly dark sooty-brown, appearing black. Long tail; extends beyond folded wings at rest. Upper throat and forehead are off-white; eye is brown with a pale blue eye-rings. Bill dark blue-grey. Feet blue-grey with black claws. It is the largest Australian falcon; 45 to 55 centimetres long, wingspan 97 to 115 centimetres. Male and female similar in appearance; females are larger. Juveniles (first year), lack leg feathers and are darker coloured than adults with narrow pale edges to feathers on back and wings.

Black Falcons live as solitary nomads of the sparsely treed, inland regions. Searches for prey from bare vantage points or flies and glides on sharply pointed wings with straight trailing edges. Searching flight can be low-level or involve high soaring for long periods without flapping. Prey, on the ground or in flight, is pursued with rapid, vigorous, wing-beats and snatched in mid-air or off the ground. Birds up to the size of galahs, ducks and native hens are taken, larger birds such as herons and waterfowl are rarely attacked. Small rabbits and rats are taken on the run.

Black Falcon - page 2
Sometimes hunts cooperatively in pairs; follows grass fires, farm machinery, livestock, shooters and other raptors to seize flushed prey; robs other raptors if opportunity arises.

Usually seen soaring lazily or perched on a vantage point, rarely perched on a fence post (but not on wires like the Brown Falcon). In arid and semi-arid regions tends to gather around water sources (such as bore drains or wetlands) because of the presence of prey birds.

Breeds between about June and December. Mating is for a season. Pairs (or solitary birds) soar and perform aerobatics with wing-beats, diving and mock attacks or fast chases at low-level. Black Falcons do not build a nest but take-over a large abandoned stick nest in a living or dead tree about 4 to 14 metres above ground - sometimes a nest on power line pylon is used. Three or four eggs are laid; pink-buff heavily spotted with red-brown; rounded-oval 54 mm by 40 mm. The female incubates the eggs for about 34 days while the male hunts and passes most of his kills to her at a perch near the nest. Nestling period is 38 to 49 days. Young birds remain dependent after fledging for at least two weeks and possibly longer.

Found over much of the Australian mainland except densely forested parts; sparse in the south-western third and coastal south-east. Widespread but generally uncommon; can be locally common in arid areas during wet years. Nomadic to local depending on the abundance of prey species. Probably regular migrations northwards from south-eastern Australia for winter, returning south for the summer.

Egg shell thickness was not significantly reduced while DDT was used in Australia.

 ¶  Genus Falco is the only genus in Family Falconidae and contains other Falcons, the Australian Hobby and the Nankeen Kestrel.