Sociable weavers (Philetairus socius) seeking shade whilst perched on the branch of a Camelthorn tree. This small African bird lives in large flocks, foraging for seeds and insects. The members of a flock co-operate to build a large communal nest. Each breeding pair has its own entrance. The nests, which the birds thatch (rather than weave) from twigs, grass and straw, can reach over 7 metres in length and mass over a tonne. A single nest can house up to 400 birds, providing shelter from extreme temperatures. Photographed in the Kgalagadi Transfrontier Park, Southern Africa.