The Masked Weaver

Botlhaga, Bofefo, Botswerere, Botho, Bonatla – the five Bs epitomise this industrious bird, and it is small wonder that it has been chosen as a symbol of productivity in Botswana. A breeding colony of weavers is a hive of frenetic activity during summer as the males construct their beautifully woven, spherical nests and then hang below them, flapping feverishly to attract the drab females, each making a continuous swizzling call to outdo his neighbour. There is nobody in Botswana who hasn’t been impressed by the innovation, responsiveness, creativity, and diligence of the weaver-bird.

The male weavers develop their bright yellow breeding plumage in spring following the onset of warmer weather and the first rains. They begin the painstaking task of constructing their specialised nests, unique among birds, by flying to tall grasses or palms and tearing off long strips. They do this by nipping a blade of grass or frond tightly in their beaks and then flying sharply and strongly upwards, carrying the strip for sometimes several hundred metres to their chosen nesting site. They start the nest by wrapping the strips around the fork of a pendant twig – after a number of pieces have been added, the loose ends hang down in two separate, trailing tassels. These are then brought together to form a circle which becomes the structural basis for the whole nest. More and more strips are added to this ring, the male standing on it as he carries out his intricate weaving. Stretching out as far as possible with each building action, the bird gradually forms the dome of the nest. The construction of the nest involves deft beak-and-claw actions of a highly specialised kind, and the male weaver uses three main types of stitching: knotting, weaving and twining. When knotting, he holds the grass with one or both feet and then pulls, pushes and twists it around his bill. He is capable of tying slip-knots, overhand knots and half-hitches. When weaving, he performs the complex movements of the best of the Etsha basket-weavers as he forms and extends the fabric of his remarkable nest. When twining, he uses his beak like the fingers of a tapestry weaver from Oodi, threading a new grass strand in and out of the nest wall, and adding strength by employing a variety of loops.

Photo - Bergh

All this is not done at a leisurely pace – numerous other males will be competing nearby, and when the nest is complete, it will become a status symbol that will attract a mate. This is why his work must be completed in a highly efficient manner – as unlikely as it seems, the construction of a single nest takes a mere two to three days from start to finish. The BNPC code of conduct sometimes breaks down when an over-zealous male steals strips of grass from his neighbour’s nest to speed up the process!

The appearance of a female in the vicinity of the nests elicits an immediate response from the male – he hangs below the nest with feathers puffed out, wings flapping frantically in a dazzling advertising display. The unadulterated joy of the male as a female chooses to enter his nest has to be seen to be believed! The females are exacting ‘customers’ however, and she checks the nest thoroughly for quality; for a weaver it is not good enough to simply produce a nest in a timely fashion – it must meet a certain standard! Although male weavers have been shown to weave their nests instinctively, there is no doubt that practice makes perfect, and experienced males produce better nests and are more likely to secure a mate than younger birds. If the female rejects the nest, a remarkable thing happens – the male tears it down! Even this is not done in a half-hearted fashion – it is done with a vengeance, and soon the male is hard at work again, striving for a better creation.

If the female weaver is satisfied with the nest, she provides a soft inner lining, and after mating lays their clutch of two or three speckled eggs, while the male adds a short, narrow entrance tunnel to the chosen nest. With his mosadiwantlha safely ensconced in the nest, the male now sets about attracting a second, then a third or fourth wife – the rewards of being productive are high, and a BNPC male may have up to nine!

The female incubates the eggs for two weeks before the chicks hatch, and although she feeds them alone, the solid foundation created by the male serves the family well throughout this period. During the torrential summer downpours, or even hailstorms, the nest bounces around a bit, but the occupants are warm and dry inside. They are safe too from snakes and other predators – the nest is always placed at the end of a hanging branch and the male takes care to strip off all leaves to make the approach of a snake difficult and conspicuous. Gabar Goshawks and other raptors, despite having strong beaks and talons, are hard-pressed to tear the well-woven nest fabric.

Weavers do however face a far more insidious threat that the nest, no matter how well constructed, cannot avert – in fact, it may partly result from the fact that the nest is so well made. Sometimes broken eggs or even dead weaver chicks can be seen beneath the nests, and at first sight this is not easily explained, as neither eggs nor chicks are eaten. However, these nests have been infiltrated by the Diderick Cuckoo – a nest parasite that lays its egg in the safety of the weaver nest when it is unguarded. The Diderick Cuckoo is well aware of the weavers’ diligence, and has chosen them as foster parents for its own treasured offspring. The cuckoo’s egg has a very short incubation period so that its chick hatches before or soon after the weavers – it immediately pushes anything in the nest out through the entrance, onto the ground below. Top quality products like weaver nests are always highly sought after, and not necessarily by legitimate means only!

Is there a message for us here? Perhaps there are many, depending on circumstances and personal viewpoints. My conclusion is this: we live in a diverse world where productivity and hard work win the day – most of the time!

A family of Black-faced Waxbills sleeping in a disused weaver’s nest

- top of page -

about us - Botswana for birders - conservation - membership - supporters - news - publications - contact us