The sooty falcon is an attractive, medium-sized (34cm) bird of prey with long, slender wings and a long tail. Although the adult plumage is mainly uniform grey, in the male it is pale with a bluish tinge, while in the female it is a darker, sooty shade.
Both the flight-feathers and the area below the eyes are significantly darker than the rest of the body, and some individuals possess a small pale patch on the throat. In contrast to the dark plumage, the bare areas on the legs, around the base of the bill and the rim around the eyes are bright yellow.
The juvenile’s plumage differs quite significantly from that of the adult’s. The head and nape are light brownish, the upperparts are brownish-grey edged with yellowish-white feathers, while the underparts are brown and heavily streaked with brownish-grey. A dark stripe extends from the base of the bill, and the throat and lower cheeks are cream coloured. By its first summer, the juvenile undergoes a considerable change in coloration becoming a much darker, uniform grey than the adult, with conspicuous dark barring on the undersides of the wings and tail.
The sooty falcon is one of only six species of completely migratory birds of prey worldwide that breed in the northern hemisphere and overwinter in the southern hemisphere. Although sooty falcons begin to arrive at their breeding locations in the spring, around late April, they do not commence breeding until late summer. This delay occurs so that chick-rearing coincides with the autumn migration of small birds from cooler temperate regions in the North, which provide an abundance of food for the sooty falcon chicks. During the breeding season, sooty falcons form breeding pairs which either nest alone or in loose colonies of up to 100 pairs. Its nest is a shallow depression dug into the ground and breeds in hot, arid environments; on cliffs, small rocky islands and rugged desert mountains. The female lays up to four eggs in a scraped out hollow in the ground or amongst rocks, which in the summer heat may be exposed to temperatures of around 50 degrees Celsius. After around a month, despite the extreme conditions, the majority of sooty falcon eggs hatch successfully. The breeding season ends in late October, and the adults and juveniles begin the long journey to the wintering grounds in Madagascar and southern Africa. Here, the sooty falcon mainly subsists on large insects, but also bats and small birds.
A specialist in migratory bird hunting, the sooty falcon is generally most active at dusk and dawn, when solitary individuals can be seen perched on rocks or vegetation, scanning the sky for passing migrant birds. When a bird flies overhead, the sooty falcon rapidly takes to the air, accelerating above its prey before making a low dive and seizing it in its talons. Species taken include the hoopoe (Upupa epops), the European bee eater (Merops apiaster) and a variety of warblers.
Distribution and population: the sooty falcon breeds in scattered, highly localized colonies in northeast Africa (highly locally from Libya, eastwards through Egypt to the Red Sea islands off Sudan, Djibouti and Ethiopia, islands and coasts of northwest), the Middle East and islands off the coast of southwest Pakistan. The greatest numbers of sooty falcon are found around the Arabian Peninsula, principally on the coastal islands of Saudi Arabia, Yemen, Oman and the Emirate of Abu Dhabi. A few inland breeding records from Saudi Arabia show that its range extends to the interior of the region. After a lengthy migration, the majority of the population overwinters in Madagascar, although a small proportion migrates to coastal Mozambique and eastern parts of South Africa.
This species has been classified as Near Threatened, because it is suspected to have a moderately small, declining population. Detailed surveys and robust monitoring are much desired, and would lead to a clarification of its status. A slow or moderate and on-going population decline is suspected on the basis of fragmentary population figures and surveys.