Avian clutch size of increasing clutch size with increasing latitude. The proximate and ultimate causes for this pattern have been a subject of intense debate involving the ideas of group and individual selection. David Lack observed a direct relationship between latitude and avian clutch size. Birds near the equator laid approximately half as many eggs as those that resided in northern temperate habitats. He observed an increasing clutch-size from the equator towards the poles (something he referred to as the “latitude trend”) for many passerine (perching) birds, near-passerine (tree-dwelling) birds and in various other groups: Strigiformes, Falconiformes, Ciconiiformes, Laridae, Ralliformes, Galliformes, Podicipedifomes, and
Birds of Eden Birds of Eden Birds of Eden is the world's largest free flight aviary and bird sanctuary, located near Plettenberg Bay in the Western Cape, South Africa. The mesh dome of the sanctuary was built over of indigenous forest, and is up to above ground level. of walkways, about 75% of which are elevated, let visitors see the birds at all levels of the aviary. Birds of Eden is one of the three Sanctuaries under The South African Animal Sanctuary Alliance (SAASA). As a member of SAASA Birds of Eden was honoured with four major tourism awards in 2014. The four