Owls | Strigiformes

Uilen | Rapaces nocturnas

Hunters with a large, broad head in which both eyes face forward, so that the fields of view overlap and the bird sees depth; the eyes are tubular and fixed in their sockets, which is why an owl turns its whole head — fourteen neck vertebrae allow well over half a turn. A disc of short, stiff feathers around each eye guides sound to the ear openings, and in a number of species those openings sit at unequal heights, so a sound can be placed in the vertical as well and a strike made in complete darkness. The plumage is soft and downy and the outer primary carries a comb-like leading edge, so the wingbeat is all but silent; the outer toe is reversible and the claws are long and strongly curved. Prey goes down whole and what will not digest — bone, fur, feathers, beetle wing cases — comes back up as a pellet; the white, almost round eggs are laid in a cavity, a rock crevice or a disused nest with nothing built by the bird itself, and because incubation begins with the first egg the young of one brood differ greatly in size. Southern Africa holds two families side by side: the barn owls, with a heart-shaped disc and long, thinly feathered legs, and the typical owls, with a round disc.

Families in this order

Typical owls | Strigidae11 speciesThe facial disc is round and the eyes are large, with an iris ranging from yellow to almost black; several species carry two erectile feather tufts on the head, which have nothing to do with hearing but do break up the head's outline. The inner toe is shorter than the middle toe and the middle claw is smooth. Within this one family size in southern Africa runs from a scops owl of sixty grams to an eagle-owl of more than three kilos, the toes here being generally bare or merely bristled. The fishing owl departs from nearly every one of these points: legs and toes are bare, the soles are set with sharp spicules that hold a slippery fish, and the sound-deadening comb on the outer primary is absent, since a fish under water will not hear the approach in any case. The voice consists of low, far-carrying notes, rattles or clear whistled series that hold the territory outside the breeding season as well, and is usually the first thing by which the species is known. Nesting is in a tree hole, an old crow or raptor nest, on a cliff ledge or simply on the ground; the female incubates and broods, the male brings in all the food.
Barn owls | Tytonidae2 speciesThe facial disc is heart-shaped and drawn down into a narrow point; the eyes are small and dark for an owl, the head is narrow and the legs are long and feathered to the toes. The inner toe is as long as the middle toe, and the claw of that middle toe carries a row of fine teeth used to comb the disc clean; the breastbone is fused with the wishbone. Hooting is absent: these birds hiss, snore and shriek. They hunt low and quartering over open rough ground, almost entirely on mice, voles and shrews, and breed in a dark cavity in a building, cliff or tree; clutch size follows the rodent supply, so a good year can bring two broods and a poor one none at all.