A NEW GEOGRAPHICAL RACE OF THE GOLDEN-TAILED WOODPECKER FROM SOUTH-EASTERN AFRICA,WITH NOTES ON THE OTHER SOUTH AFRICAN FORMS

Maclean, G. L. 1974. Egg-covering in the Charadrii. Ostrich 45: 167–174.

Deliberate egg-covering in the Charadrii (waders) occurs in at least 13 species in four families (Jacanidae, Glareolidae, Charadriidae and Thinocoridae). The habit is most widely developed in the genus Gharadrius, of which at least four species cover their eggs. Egg-covering is done by kicking material over the eggs with the feet in most species, but in the Glareolidae and probably some other groups, only the bill is used.

The primary function of egg-covering appears to be concealment, but the secondary function of thermoregulation appears to have become almost as important in a few species, especially as a device to insulate the eggs against exposure to the sun. It is not surprising that egg-covering is most highly evolved in tropical and subtropical regions where predator-pressureMaybe higher, and the danger of overheating by direct sun is greater, than elsewhere.