|Rynchops flavirostris||Order: Charadriiformes||Family: Laridae (Gulls, Terns, and Skimmers)|
This splendid bird, related to America’s own Black Skimmer, is found along rivers, lakes and lagoons in Sub-Saharan Africa. I saw my lifer in Uganda. This one has an entry in Guinness World Records:
African Skimmer: Most heat-tolerant bird. It is not uncommon for any desert-dwelling bird to experience temperatures in excess of 40°C (104°F) on a fairly frequent basis. Some of the hottest relative conditions, though, are endured by a gull-related species known as the African skimmer (Rynchops flavirostris), which is indigenous to lakes, lagoons, marshes, estuaries and rivers in sub-Saharan Africa. On some of its breeding beaches, notably Kenya’s Lake Turkana (formerly Lake Rudolf), which is the world’s largest permanent desert and alkaline lake, the ground surface temperature can reach 60°C (140°F), and even the air temperature just above this ground can reach 40°C (104°F). Indeed, the ground is so hot that in order not to burn its chicks and eggs when it returns to them, while still in flight the skimmer will lower its feet into water to splash onto its belly in order to cool its surface down before returning; this characteristic behaviour is known as “belly-soaking”.
The three species of skimmer are instantly recognizable by virtue of their extraordinary beak, in which the lower mandible is significantly longer than the upper one. This remarkable evolutionary adaptation increases its feeding efficiency, because the skimmer obtains its fish prey by flying over the surface of water with its beak open and the lower mandible partly submerged, skimming through the water, then snapping its beak shut as soon as its lower mandible comes into contact with a fish.