27 Mar 2014

Sociable or social weavers are a marvel to watch. With their intriguing cooperative behaviour, these small birds are really sociable; they succeed where human beings struggle.

The sociable weavers are highly cooperative and live in large colonies they build and maintain communally. They are not even jealous.  They accommodate strangers in their nests.

According to bird specialists, these birds are called “social” not because they live in organised colonies but given their ability to build massive homes out of sticks, grass and cotton that become home to several other bird species. The nests are so large that other bird species are welcome including predators such as owls and eagles.

But for human beings where individuals collaborate for communal tasks, there is likelihood of conflicts around sharing the resources or workload. For example, in Botswana cooperative societies and borehole syndicates which were common amongst Batswana have collapsed due to lack of unity and cooperation.

Cooperative societies have worked well for Batswana. Through initiatives such as Ipelegeng and Letsema, men and women in villages would collaborate to construct kgotla shelters, drift fences and dams for the benefit their villages, but this has since disappeared mainly due to conflicts and greediness that arise from sharing of resources.

But for sociable weavers, communal nest structures are a common good that require constant work to repair and enlarge year round. The weavers are highly gregarious all year if not throughout their life span.

Amazingly, those that immediately graduate to adulthood inherently provide the younger ones with food while parents may as well provide for their neighbours’ young. It is rare in a human set-up given the economic challenges and other issues associated with modernity.  

Sociable weavers nest and feed in colonies and they are well known for their nest building abilities. This is why they are found in the Kgalagadi Trans-Frontier Park of Botswana, Namibia and South Africa, where the terrain in characterised by stiff grasses which are used for building nests.

Their nesting in the park, beautifully illustrates the realm of wild animals overlapping with human civilization. The bales of hay draped over the tops and sides of trees, even on electricity pylons, are home to hundreds of these songbirds.

While the merging of human and wild landscapes is powerful, perhaps the bigger oddity here are the nests themselves. Why would birds choose to live in a nest complex at all? These nests are far more than apartment complexes for sociable weavers; they house multiple generations that work together to raise chicks.

Wildlife Officer 1 at the Trans-frontier Park, Mr Basimane Mokara says most songbird species breed before they even turn a year old. Sociable weavers rarely breed before the age of two but instead, these younger birds help raise other nestlings, their siblings as well as unrelated chicks by gathering food and maintaining the nest’s fluffy interior chambers and external sticks and grass.

Mr Mokara says once they grow up, they live for a longer time of up to ten years. He reckons that their long life span allows them more breeding time. Once they start breeding it is all they do.

Mr Mokara says the weaver birds are common in dry areas in the southwest region of Botswana and are usually seen in small flocks around their enormous communal nests that are nicely crafted from straws and grass with thorny twigs roof over their heads.

He says the rounded nests chambers are on the underside of the mass of straw, each with vertical entrance tunnel. The nest, he says, is used throughout the year and is kept in good condition while the birds stay in pairs only when breeding. Otherwise, they occupy any chamber and may roost in groups of up to six per chamber.

Regarding their diets, Mr Mokara says the sociable weavers are insectivorous with insects comprising 80 per cent of their diet. Normally, they never have to drink water as they obtain all their water from a diet of insects and they also feed on seeds and other plant products whereas foraging is predominantly on the ground, but also on bark and tree leaves.

He says populations of this bird have increased this century, perhaps due to increased availability of nesting structures such as electricity pylons and other man-made structures and most of its present distribution is unlikely to see any major man-made alteration and its future in these areas is secure.

But the secret behind these birds willingness to share the huge nest they worked so hard to make is security. More residents mean more eyes keeping a watch for danger, according to experts. And the weavers often learn from other birds where new sources of food can be found.

Mr Mokara says its extinction can only occur when the acacia tree is cleared and probably in other areas the encroachment due to overgrazing. The underlying factor here is that of unity and cooperation. Can it be said that sociable weavers when it comes to unity and cooperation have done far much better than the human folk? Why is it that our cooperative societies and other syndicates find it difficult to survive?

May be that is why government found it fit to revive these societies because there is no doubt that in the past they performed well for the country. Let us take a cure from the sociable weavers. Ends