Black Falcon

The Black Falcon, Falco subniger, is a medium-large raptor endemic to the vast landscapes of Australia. Exhibiting sexual dimorphism, females are notably larger than their male counterparts. Adults measure from 45 to 56 cm in length, with the tail accounting for about half of this measurement, and boast a wingspan ranging from 95 to 115 cm. The species is characterized by its uniform dark brown to sooty black plumage, with juveniles typically presenting a darker shade than adults. A distinctive dark stripe may be observed below the eye of adults, and variations such as a white chin or spots on the underwing coverts can occur. The cere, eye ring, and feet are a pale grey or blue-grey, while the eyes are dark brown and the beak tip is black. The talons, used for capturing prey, are also black. Chicks are covered in white down, contrasting sharply with the adults' dark hues.

Identification Tips

When identifying the Black Falcon in flight, focus on the silhouette, including the shape of the wings and proportions, as well as the flight style and vocalisations, rather than the intricate details of colouration. The Black Falcon can be distinguished from hawks by its toothed upper mandible and long, pointed wings. It is often confused with the Brown Falcon, especially the juveniles and black morphs of the latter. Key differences include the length of the exposed tarsi relative to the thigh feathers, flight style, wing attitude, and the presence of bold underwing and tail barring in the Brown Falcon.

Habitat

The Black Falcon favors the arid and semi-arid zones of Australia, often found near watercourses or utilizing isolated trees. It hunts over open wooded grasslands, saltbush plains, and other areas with low vegetation. In arid regions, it may also be seen hunting over wetlands or near artificial or temporary water bodies that attract abundant birdlife.

Distribution

This species is widely distributed across all mainland states and territories of Australia, with the exception of densely forested areas. It is sparse in coastal areas of southeastern Australia and only occasionally seen in the southern interior of Western Australia. There have been occasional records of non-breeding vagrants in New Zealand.

Behaviour

The Black Falcon is known for its interactions with other bird species, including both harassment and being harassed by raptors and corvids. It is often observed resting on power poles during the day but avoids sitting on wires.

Flight and Hunting Style

The Black Falcon exhibits a variable flight pattern, with relaxed 'crow-like' wingbeats and occasional soaring. It also demonstrates a stiffer, shorter wingbeat, and glides and soars with wings slightly drooped or horizontal. The tail is typically folded, except when soaring. The falcon is adept at catching prey both in the air and on the ground, using powerful, rapid wingbeats during pursuit. It hunts primarily alone but can also hunt cooperatively, especially when prey is abundant.

Diet

The diet of the Black Falcon consists mainly of birds ranging from finch to cockatoo size, but it also feeds on small mammals, insects, and carrion. A variety of avian prey has been documented, including various pigeons, Australian pipits, magpies, and many others.

Breeding

Breeding occurs between May and November, with a clutch size of 1 to 5 eggs, typically 3 or 4. The incubation period is around 34 days, mainly by the female, and the nestling period lasts between 5.5 to 7 weeks. The Black Falcon nests in trees, often taking over the stick nests of corvids or other raptors. Males perform courtship displays, and both parents contribute to feeding the young later in the nestling period.

Vocalisations

The Black Falcon's call is a slower and deeper 'cackle' compared to the Peregrine Falcon's, with a guttural call that becomes more rapid when threatened. Males emit a sharp, high-pitched sound during courtship, while females have a whine or wail when begging for food or copulating.

Conservation Status

The IUCN lists the Black Falcon as Least Concern, though it is considered scarce and nomadic. It is classified as Vulnerable in New South Wales and Victoria, with an estimated population of 670 to 6700 mature individuals and a stable trend.

Similar Species

The Brown Falcon is the species most commonly mistaken for the Black Falcon, particularly the juveniles and black morphs of the former. Differences in leg length, flight style, and wing and tail barring can help distinguish between the two.

Threats and Management

The Black Falcon faces threats from habitat clearing, overgrazing, vehicle collisions, and shooting. Competition for nest sites and disturbance by other birds also impact breeding success. Conservation efforts include habitat protection, monitoring populations, and research into the species' biology and ecology.