The sociable weaver is a master of construction and nests can provide home to up to 300 birds according to South African National Parks Official Information Brochure, Kgalagadi Transfrontier Park, The Tourism Blueprint, 2004. Besides providing ideal protection against the harsh elements of the semi-desert, South African pygmy falcons (Polihierax semitorquatus) rely completely on the nests of the sociable weaver to survive. White excrement around the opening of the nest indicates the presence of the pygmy falcon in the nest.
The nests are constructed in such a way that the inside temperature never exceeds 30° Celsius in summer or 15° Celsius in the winter. Some scientists speculate that regulating the temperature inside the nest helps the birds to conserve energy and this limits their consumption of water, which would explain their ability to survive in the dry Kalahari Desert.
Other birds like the pied barbet, familiar chat, redheaded finch, ashy tit, rosy-faced lovebird and even owls often co-inhabit the nests of sociable weavers as homes, nests or for protection.
Where Do Social Weavers Build Their Nests
Being endemic to Southern Africa, the sociable weaver appears to prefer the Southern Kalahari vegetation. Sociable weavers use endemic trees like Acacia erioloba (Camelthorn Trees), Boscia albitrunca (Shepherd's Tree) and Aloe dichotoma (Quiver Tree) to build their nests and rarely utilize alien tree species. The availability of stiff grasses seems to influence where the sociable weaver builds the nests.
Sociable weavers build the nest around the lower parts of the trunk of a tall tree or around a utility pole and prefer the part of the tree with no side branches. The entrances to the chambers of the nest are at the bottom to discourage predators like the Cape Cobra, Honey Badger and other tree snakes from attacking the colony and to allow easy access to the sociable weaver adults.
How the Sociable Weaver Nest is Constructed
Sociable Weavers use stiff grass to construct the outer layers of the nest giving the nest a haystack -like appearance. Strong twigs are intertwined to form the roof while dry grass is woven in between to insulate the nest. Each breeding pair then lines their chamber of the nest with various soft materials after which the entrance to the chamber is re-enforced with green grass woven together to prevent eggs from rolling out. As a defense mechanism against predators, the tunnels leading to each chamber are lined with sharp spikes of dry grass to discourage predators from reaching the chambers.
The sociable weaver maintains the nest though the whole year and the birds are usually found near the nests.
Sociable Weaver versus Humans
The habit of the sociable weaver colony to build their nests on utility poles leads to the inevitable confrontation with humans. These nests can reach an amazing twenty feet in diameter and when attached to electrical or telephone poles, may cause the conduction of electricity between the live wires and grounding wires during the rainy season, resulting in power and telephone outages.
Utility companies are placing structures lower on these poles to encourage the sociable weaver to build the nest lower on the poles, but this had limited success as the nests soon reached well above the fitted structure and caused the same problems again. Currently a workable solution has not been found, but conservationists are convinced these highly adaptable birds might be convinced not to interrupt human life too much.
The San Diego Zoo at 2920 Zoo Drive in Balboa Park, just north of downtown San Diego is the only place in the United States where visitors can view a colony of sociable weavers at work. The zoo regularly provides nesting material for these busy birds to expand their nest.
Yolande Pienaar - Yolande traveled extensively through Southern Africa and frequently visits places off the beaten track where she discovers gems to share ...
