Colours of Wildlife: Black-Shouldered Kite
Created | Updated May 22, 2018
Black-Shouldered Kite
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
This time I have for you a little bird of prey, a Black-Shouldered Kite, Elanus caeruleus. It is probably the most abundant raptor to be seen in South Africa, and indeed it occurs over the entirety of sub-Saharan Africa except for the dry tip of the 'Horn of Africa', and the driest part of the Namib Desert. Very similar and very closely related species occur in Asia and Australia. Black-shouldered kites are small, reaching only about 30 cm/12" in total length, but they're related to the much larger Yellow-Billed and Black Kites, also found commonly in Africa, and also to other eagles and hawks. They're not closely related to falcons, which today are classified in a distinct family quite apart from the other raptors.
Riders of the Wind
What makes the black-shouldered kite most conspicuous is its behaviour of hanging on the wind. For this, kites prefer a light wind. Facing into the wind, they maintain their position by just a slight fluttering of their wingtips. Even though they are actually maintaining a low forward speed relative to the air this way, in practice they're hanging motionless above the ground surface. They typically choose a height from about 20 to 60 m above the ground. They hang in place, head curved downward and bright red eyes focused on the ground surface. Like other raptors they have exceptional eyesight. Scanning between the bushes and tufts of grass, they will notice the slightest movement that gives away an item of likely prey. These might be small mammals, ground birds, or lizards. They catch a small number of insects also, but their preferred prey is rats, especially the chunky vlei rats, and mice. A kite hunting for these will hover in one spot for ten to twenty seconds, then move on a bit, and hover in the new place, and go on like that, scanning the surface methodically. Having spotted a likely victim, the kite will fold its wings, drop almost straight to the ground, and grab it with its strong clawed feet. It will then fly to a perch to feed on it, if it's a large-ish critter carefully tearing it apart and swallowing it in chunks. The intestines are often discarded.
Though this hovering hunting technique is the most spectacular, it is actually not the kite's most often-used method. For about three quarters of the time, it prefers a much less energy-intensive method: sitting on a high perch and scanning the ground from there. They take advantage of the many telephone poles erected by us humans; perched up there, they're also very easy to see. While much less labour is involved, this means that the kite is dependent on some critter moving within sight of its perch, while when it hovers, it can venture over a much larger, open area, far from any perches. So, while perch-hunting delivers more food for the amount of energy spent hunting it, hover-hunting results in a much larger number of successful catches per unit of time spent. Any individual kite will therefore combine the two so as to best meet its own needs.
When not hovering, black-shouldered kites fly with a light, buoyant and fast action, somewhat reminiscent of seagulls. This they use to move from one hopeful hunting area to another. They are hard workers, often hunting from before dawn until after dusk. While perched, a kite will from time to time raise its tail conspicuously, showing off the white undertail feathers. This is a visual signal for other kites in the region to show that it is there, and that it is hunting. Kites are not tolerant of others of their own kind intruding into their hunting-grounds, and tail wagging is a show of aggression.
At the end of the day's work, however, the kites throw off their mutual aggression and come together at communal roosts. These may be in beds of reeds, or in trees. From far and wide the kites come gracefully flying in; eventually 50-70 or even as many as 150 birds may roost together.
Like other raptors, black-shouldered kites bond into pairs to breed. While they're silent most of the time, the male and female greet each other with a thin, high 'pee-yoo' whistle. They utter this frequently as part of their courtship displays, the male and female flying in circles, diving at each other and even grasping each other's claws and cart-wheeling in the air. People who don't know of raptor courtship often interpret this as a fight, but actually it's an act of intimacy between a loving couple, like dancing. The male also performs a 'butterfly flight' for his woman, flying around with rather stiff wings and dangling his legs down. He also impresses and satisfies her by bringing her food items. They can breed at any time of the year, but prefer to do it when lots of food is available, such as at the end of the rainy season. They can breed several times in any one year. They build a rather flimsy nest from sticks, twigs or twiggy weeds, lined with dry grass. Nest sites are usually thorny trees or bushes, below the topmost branches but easily accessible from above. The female lays two to six eggs. Unlike the large raptors like eagles, there is no sibling aggression. The chicks are downy upon hatching, with a proportionally very large head and eyes that are just barely open. Their parents tear their prey into pieces for them at first, but at the age of three weeks they can swallow mice and small rats whole.
For the first two weeks, the mother stays with the chicks while the father brings them food. After that, the female goes out hunting as well, leaving the chicks alone for long periods. They lie still, and if threatened, will flatten themselves in the nest. Their greyish-brown down and feathers give them good visual camouflage. At the age of four or five weeks they're ready to leave the nest. They start stretching and flapping their wings, and move off the nest to nearby perches, finally taking their first flights. They still remain close to the nest and accept food from their parents for a while. At the end they even take prey from their parents while they're in flight. It's actually mainly their father that cares for them at this point; they stay with him for up to three months after leaving the nest. Youngsters may travel very far to seek their own hunting grounds. But even adults will travel widely if environmental conditions change to make prey rare in a certain area. The kites flourish at times and places experiencing population booms of rodents.
Being widespread, versatile, and very efficient and successful hunters, black-shouldered kites are not at all threatened at present.
