[order] Falconiformes | [family] Accipitridae | [latin] Elanus caeruleus | [UK] Black-Shouldered Kite | [FR] Élanion blanc | [DE] Gleitaar | [ES] Elanio Común | [IT] Nibbio bianco | [NL] Grijze Wouw

Grijze Wouw determination

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Much smaller than other kites; similar in length to Kestrel but stouter. Owl-faced, large-headed raptor, with mostly pale plumage and comparatively broad wings. It recalls small, short-tailed male harrier rather than kite. In adult, contrast of black shoulders and underside of primaries with otherwise grey or white plumage unique in west Palearctic raptors. Juvenile has buff foreparts and dark brown mantle, with feathers there and over forewing obviously fringed pale brown or white.

This is a bird of open country wherever it occurs, but it can be seen in all habitat types from moderately dense savannah to open semi-desert, or even deserts, at altitudes from 0-9,000 feet. It roosts in trees and is on the wing early in the morning. Having taken to the wing, it spends most of each day perched on a series of perches, which may be telegraph posts or wires, dead tree stumps, or sometimes rocks where trees are scarce. When not perched it flies at a height of 50-200 feet over the grasslands, hovering at intervals, and circling into the wind in the manner of a kestrel. Its mode of maintaining position during a hover is unlike that of a kestrel, however. When flying from place to place it flies directly, with measured beats of its rather pointed wings, much slower than those of small falcons. When perched it often raises and lowers the tail; this action is probably a form of display.

Elanus caeruleus is resident in Iberia and south-west France, with Europe accounting for a tiny proportion of its global range. Its European breeding population is very small (as few as 810 pairs), but increased substantially between 1970-1990, and continued to increase-albeit at a slower rate-during 1990-2000. Nevertheless, its population size still renders it susceptible to the risks affecting small populations.
This species has a fragmented distribution covering most of Africa except the Sahara, south-eastern Asia, parts of Indonesia and Australia. In south-western Europe it inhabits open habitats with scattered trees. For a long time it was restricted to the Iberian Peninsula, but during the last two decades it has extended its distribution to south-western France. About 1300 breeding pairs occur currently in the European Union

The mainstay of the Black-shouldered Kite's diet is mammals up to the size of a small rat. There are taken in grasslands. A few small ground birds such as larks and pipits, and large insects, especially grasshoppers and locusts also feature on occasions. On the Arabian coast the staple diet is dead fish and offal, varied with lizards, no doubt because of shortage of other food. Most food is taken on the ground, but some insects are caught in the air.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km2. It has a large global population estimated to be 1,000,000-10,000,000 individuals (Ferguson-Lees et al. 2001). Global population trends have not been quantified, but populations appear to be stable (Ferguson-Lees et al. 2001) so the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

The nest is built by the birds themselves, and a new one is built every year, though the same area, or even the same tree may be used. It is a small, light structure of thin twigs, flat and loosely made, not more than twelve inches across by three inches deep. It could be at any height from five to 60 feet above ground, and is usually in a large tree standing in open ground, often a thorny one. In South Africa they seem to prefer the tops of fir trees, and when there are no trees available, like in the desert islands of the Arabian Coast, they will breed on rock ledges. Both sexes build, breaking off twigs from trees and bringing them to the site in the beak. The male brings most of the material which is then worked into the nest by the female. Three to five eggs are laid at intervals of two to three days. In temperate regions the eggs are laid in spring, but in tropical regions the breeding season is elastic and may even extend into wet periods.
The female carries out most, if not all of the incubation. She is fed on or near the nest by the male during the incubation period. Both birds are likely to be aggressive if the nest is disturbed during this period, and they vigorously attack other raptors and crows passing near by. The incubation period is about 26 days (25-28). The eggs hatch at two to three day intervals, so a brood of four will take a week or more to hatch;. Although this results in wide variation in the size of the chicks, the older chicks are not usually aggressive to the younger, and all are sometimes reared. This is one of the rare predators with a possible second brood.
The feathers appear through the down at about twelve to fourteen days, and the young are fully feathered by 21 days. They are ready to fly at 30 to 35 days. In exceptional conditions on the Arabian Coast the fledging period exceeds 40 days, probably due to lack of food. The young return to the nest at intervals after their first flight, and are fed by their parents away from the nest. ln the early fledging period the male brings all the prey and the female remains at or on the nest, tending the young. Later the female takes the major part in killing for the brood, but the male remains for long periods near the nest and takes some share. The female alone feeds the young, the male only bringing prey to the nest. She continues to feed them until they are feathered, at about twenty days, but thereafter drops prey on the nest and leaves them to tear it up. With a large brood, of three or four, she feeds all the young and does not favour the largest.

Mainly resident, at least in west Palearctic, but in tropics subject to erratic movements which may occasionally be on large scale in search of conditions supporting abundant prey. Evidence from India of periodic fluctuations, possibly eruptive, numbers sometimes appearing in areas where previously scarce or absent, then virtually disappearing again after a year or two. In tropical Africa, seasonal movements reported in west, but in East Africa somewhat nomadic, numbers in any one area fluctuating according to relative abundance of rodent and insect prey, often travels long distances, and even crosses equator.