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 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. BirdLife International also lists occasional, non-breeding vagrants to New Zealand.
Total distribution area has been estimated at 5,910,000 km2.
The black falcon's habitat is usually in the arid and semi arid zones. It is usually found near watercourses or utilizing patches of isolated trees. It hunts over open wooded grasslands, saltbush plains, bluebush plains and other low vegetation. In arid areas it will hunt over wetlands or near artificial or temporary water bodies – areas which tend to attract the most abundant birdlife.
The black falcon is known to both harass and be harassed by other bird species, including raptors and corvids. It may be found resting on power poles during the day but will not sit on wires.
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. Avian prey species include:
Debus & Zuccon also observed the black falcon hunting turquoise parrot (Neophema pulchella ) and apostlebird (Struthidea cinerea ), but on these occasions the attacks were unsuccessful.
Laying time: between May and November (usually July to September). Clutch size: 1 - 5 (usually 3 or 4). Egg size: 42x32 mm. Incubation: approximately 34 days (by female, possibly by male for short periods). Nestling period: 5.5 – 7 weeks. Life span: at least 12 years in the wild, and 20 years in captivity.
The black falcon nests in living or dead trees, using the stick nests of corvids or other raptors. It may take over nests occupied by other birds. It appears there may be interspecific competition for nest sites between the black falcon and other raptors and corvids. 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.
During breeding season males perform courtship displays such as horizontal figure eights around the nest. The male bring food to the female during incubation and brooding. During the later nestling period both sexes may forage to feed the young.
Post-fledging behaviour and development of young falcons appears to be very similar to that of the peregrine falcon, and includes spending time with siblings and parents, and practicing hunting, territorial and courtship behaviours.
