About Falco vespertinus Linnaeus, 1766
Falco vespertinus Linnaeus, 1766, commonly called the red-footed falcon, is a medium-small, long-winged falcon species. Adult males are entirely blue-grey apart from red undertail and legs, and have uniformly grey underwings. Females have grey backs and wings, orange heads and underparts, and white faces marked with a black eye stripe and black moustachial stripes. Juvenile birds are brown on the upperparts and buff on the underparts with dark streaks, and share the female's face pattern. Red-footed falcons measure 28–34 cm (11–13 in) in body length, have a wingspan of 65–75 cm (26–30 in), and have an average mass of 155 g (5.5 oz).
The main European breeding distribution of this species is in southern Russia and Ukraine. It also occurs in large numbers in Hungary, Romania, and Serbia, with smaller populations in Italy, Bulgaria, Moldova, Austria, Slovakia, and Belarus. It breeds irregularly in the Czech Republic and the Baltic States, and occasionally breeds in Germany. In Asia, breeding populations occupy a relatively narrow band located somewhat south of the taiga, extending eastward to the upper Lena. Here, its range meets that of its sister species Falco amurensis, east of Lake Baikal. The northern edge of its breeding range falls between 63° and 58° north latitude, while the southern edge sits around 45° north latitude. The range runs along the north slope of the Altai Mountains, then westward follows the transition between open pine forests and treeless steppe areas of Central Asia. Further west, breeding areas on the lower reaches of the Volga and along the north coast of the Caspian Sea extend into Europe. The southernmost breeding populations are found in steppe areas north of the Caucasus and in South Georgia, with some isolated breeding areas in northern Turkey. This species winters in southern and eastern Africa.
The red-footed falcon typically inhabits steppe-type habitats ranging from Eastern Europe to Lake Baikal in Central Asia. It is a diurnal bird that lives in open country with scattered trees, and is often found near water. It is migratory, and travels far south to Africa for the winter. The red-footed falcon does not build its own nests, instead using abandoned nests constructed by other birds, including hooded crows, rooks, and magpies. It favors nests that are higher than most other available nests: chosen nests are typically 13–20 m (43–66 ft) above the ground, and within 3–4 m (9.8–13.1 ft) of the top of the host tree. Most selected nests are located near the edge of woodlands, and the species avoids nesting on solitary trees. Breeding occurs in these abandoned nests, and the species usually breeds colonially in rookeries, as these falcons remain in groups. Colonial nesting is linked to higher fledging success, compared to solitary nesting. The red-footed falcon depends on nests built by rooks. As rook populations have declined, the number of suitable rookeries available for colonial nesting has also decreased, which has prompted the development of human-led conservation efforts for the falcon.
