The Sociable Weaver - Philetairus socius - is endemic to Southern Africa. The species ranges across northwestern South Africa, southwest Botswana and extending northwards across Namibia. They have a black chin, black barred flanks and a scalloped back. The sexes are indistinguishable.

Food

It mainly eats seeds, supplemented with termites and other insects, foraging in large flocks which pluck food from the ground.

Breeding

Breeding may occur any time of the year and is closely linked to rainfall. They may skip breeding during years when there is low rainfall and a substantial number (sometimes over half) of birds in the colony may never breed in a given season. Under typical conditions, weavers raise up to four broods per breeding cycle. Sociable weavers are known to assist in the care of younger siblings and unrelated hatchlings and nearly all pairs are assisted by helpers. A mating pair has been recorded as producing nine broods in a single season in response to repeated predation of its young.

They lay 2 to 6 eggs, which are incubated for between 13 to 15 days by both sexes and sometimes by helpers. The chicks are brooded continuously by both parents for the first 10 to 14 days of their lives, and are assisted with feeding the chicks by up to 9 helpers, which are usually young from the previous brood. The young leave the nest after about 21 to 24 days, remaining dependent on their parents for food for approximately 30 to 45 days more.

Nests

They build large compound community nests, a rarity among birds. These nests are perhaps the most spectacular structure built by any bird. The nests are the largest built by any bird, and are large enough to house over 500 birds, containing several generations at a time. The nests are highly structured and provide birds with a more advantageous temperature relative to the outside. The central chambers retain heat and are used for nighttime roosting. The outer rooms are used for daytime shade and maintain temperatures of 7-8 degrees Celsius inside while outside temperatures may range from 16-33 degrees Celsius. Sociable weaver nests are used commensally by several other bird species, most commonly the Pygmy Falcon.

The nests consist of separate chambers, each of which is occupied by a pair (sometimes with offspring) roost and breed. Nests are built around large and sturdy structures like Acacia trees or sometimes even telephone poles. Large nesting colonies can be active across several generations, sometimes over a hundred years. The nest appears like a large haystack in the tree. If seen from below, several entrances into the chambers may be seen, giving a honey-comb appearance. The entrances may be about 3 inches wide and can be up to 10 inches long. Sharp sticks may be placed to deter predators from entering. Snakes, especially Cape Cobra are the most common nest predators.

Conservation Status – Least Concern

Birdwatching

These little birds and the amazing nests can be seen on the Aves Arid Birding Tour.