True to its name, BirdLife International’s bird of the year for 2016, the Sociable Weaver, is a delightfully convivial bird. Living is large colonies; their enormous communal nests are a very distinctive feature in arid areas such as the Kalahari and Namib.
We encounter several Sociable Weaver nests on the Namib Desert and Wolwedans to Wild Horses Safaris – a charming reminder of compatible bliss among creatures. Able to survive in the harshest of conditions these engaging birds are truly desert-adapted creatures. Living off both seeds and insects, they derive almost all their moisture needs from their food.
Although called weavers, the birds do not actually weave the nests but push grass stalks into place until they have an extremely tight robust structure. The nests are used for both breeding and roosting throughout the year. Looking like odd shaped thatched structures with holes in the bottom, they provide refuge to more species than just the weavers. Pied Barbet, Red-headed finches and Scaly-feather Finches regularly roost and even breed in unused nest chambers. Tawny Eagles and Verreaux’s Eagle Owls sometimes make their nests on top of large Weaver nests.
The size of the nest offers a buffer against the extremes of desert temperatures –particularly the Kalahari where minus temperature are quite common in winter. The inside ambient temperature of the nest chambers is very stable compared to the outside fluctuations and the deeper the nests in the structure the more the thermal benefit. Five to six birds may occupy a chamber at times. Nests are also built on telephone and electricity poles, on buildings and on cliffs. The birds favour poles for their nests since it is impossible for their major predator, snakes to reach into the nests. Pygmy falcons and Goshawks are also frequent predators at Sociable Weaver nests although the needle-like grasses protruding from the nests make hanging on to inspect nests a very difficult job.
Sociable Weavers have a fascinating social and cooperative behaviour that extends not only to nest building and maintenance, but to raising young, being on predator watch and defending the colony. Communities are made up of nuclear breeding pairs with their young from previous breeding seasons helping to raise their younger siblings. Females seek mates in other colonies so within a colony all the males are usually related but not the females. Groups forage together and participate in mixed-species foraging – in particular the Forked-tailed Drongo which feed on larger invertebrates the Weavers disturb. The Weavers take advantage of the Drogo’s alarm calls, although the Drogo’s have been seen to take advantage of this habit giving false alarm calls to drive the weavers off to steal their food.
Like so many other desert dwelling creatures, the Sociable Weavers are able to gain almost all their moisture needs from the seeds and insects they feed on. When water is available, they can be seen drinking from waterholes and farm dams on very hot days. In extremely hot conditions they dissipate heat by panting to maintain a stable body temperature often retreating to the relatively cool nests in the middle of the day.
These islands of sociability in our extraordinary desert are delightful reminders that, even in hyper arid areas, where life would appears to be a struggle, there are these communities of enchanting little birds happily going on with their companionable lives.
In her Oscar acceptance speech Jenny Beavan said something remarkable about Mad Max, Fury Road, the film for which she won her second Oscar for costume design:
“This film could be horribly prophetic…. if we are not kinder to each other, and if we don’t stop polluting our atmosphere, this could happen…”
Hopefully those who are fortunate enough to encounter with one of these delightfully sociable hubs in our beautiful Namib will be reminded that life can be convivial – it is simply a matter of attitude, and we are wholly responsible for that...