African Wildlife & Environment Issue 80

BIRDING

The remarkable AFRICAN SKIMMER

Distribution and habitat The African Skimmer is found from Senegal to northern parts of the Congo River, and southern Nile Valley, southern Tanzania to the Zambezi Valley, and then to KwaZulu-Natal Province and Angola. In recent times regular reports of the birds have been received from the Limpopo Province, especially in the Kruger National Park and Tzaneen areas. Occasional sightings also in the Vaalkop Nature Reserve area of North West Province. They normally live in large tropical river areas with sandbanks for nesting and roosting, lake shores, and coastal lagoons. The African Skimmer is uncommon, and the total population is estimated at 15,000–25,000 individual birds. African Skimmers have long wings with a deliberately high flight action so that the wing tips always remain above the water. The bird has a black back, hindneck, and crown. The forehead of the African Skimmer and the rest of the body is white, with a bright, long, orange beak that ends with a yellow tip (black tip when immature). Their short forked tail is white, and their legs are bright red. The average size of an African Skimmer is about 38 cm long. The Black Skimmer (North America) and the Indian Skimmer are both quite similar to the African species.

JohnWesson Photographs: Albert Froneman

Their voice is a sharp "kip-kip", which may be due to their bill structure, which is unique. The lower mandible is much longer than the upper mandible and is flattened sideways like scissor blades. This structure has evolved so that the bird can cushion the shock of continuously striking the water. Also, to cushion the shock of continuously striking water, skimmers have extra skull and vertebrae attachments with linked strong muscles. A remarkable feature of the three skimmer species of the world (family Rhynchopidae), not found in any other birds, is an adaptation evolved to enable them to nest on dazzling white sands of the sandbanks, and to fly low over dazzling water. These birds have a vertical split pupil like that of a cat, enabling efficient glare control with more rapid opening when required.

55 | African Wildlife & Environment | Issue 80 (2021)