Colours of Wildlife: Shaft-Tailed Whydah
Created | Updated Nov 23, 2014
Shaft-Tailed Whydah
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Today I bring you a deceptively pretty little birdie! This is the Shaft-Tailed Whydah, Vidua regia. It's scientific name means 'regal widow'. The 'widow' part comes from the related widow-finches, with which it shares its genus, and which got their names from their all-black plumage. Whydahs differ from the widowfinches in having white or buffy plumage in addition to black, and in having greatly lengthened tail feathers. At least, these characteristics belong to the breeding males of the birds. The females, and males outside the breeding season, have drab stripy plumage, and then all the species look very much alike. There are nine currently recognized species of whydah, and an unknown number of species of widowfinch. The latter are almost completely indistinguishable except in terms of song and breeding behaviour, about which we still need to learn a lot. Whydahs and widowfinches only occur in Africa. The rather different Cuckoo Finch is sometimes classified with them.
Parasitic Beauties
Whydahs are parasites! At least, brood parasites. This means they lay their eggs in the nests of other birds, like cuckoos do. Actually while cuckoos are famous for this, not all cuckoos are parasites. In fact, only the 'true' cuckoos do that; a great many other members of the family, like the coucals, ground cuckoos, couas, malkohas, guira cuckoos, anis and roadrunners, raise their own chicks. The whydahs and widowfinches are all parasitic. If they are considered to be a family, then they and the honeyguides (which also occur in Africa) would be the only bird families that are entirely parasitic.
The parasitism of the whydahs is actually in ways more sophisticated than that of the cuckoos. The major difference is that, unlike cuckoos, whydah chicks don't kill or evict the eggs or chicks of their 'foster' parents, instead growing up right along with the 'real' chicks. Whydahs, like widowbirds, parasitize waxbills, of which there is a great diversity of species in Africa. They are considered to be fairly close relatives of waxbills, in fact. Whydahs are very similar in size to the waxbills they parasitize. Their eggs also look almost exactly like those of their waxbill hosts, except for sometimes being a bit bigger. But the mimicry goes furthest in the chicks. Waxbill chicks have strange, vividly coloured spots, knobs and ridges on the insides of their mouths. In every waxbill species, these form a different arrangement with different colour patterns. When waxbills feed their chicks, they focus on these vivid markers. Whydahs and widowbird chicks have exactly the same configuration of these mouth-markers as their waxbill hosts! They also have similar plumage and feeding/begging behaviour. So, while we can consider a reed warbler to be very stupid for feeding a cuckoo chick that is much larger than itself and looks nothing like it, we can't say the same for the poor waxbills rearing the whydah chicks.
Being brought up along with the waxbills, the whydah chicks also mimic the behaviour of these. This goes so far as that the whydahs learn to 'speak' from their waxbill parents. They learn the same calls as the waxbills. But when they reach adulthood, they detach themselves from their waxbill families and start behaving differently. Male whydahs develop their breeding feathers. The shaft-tailed whydah is easy to recognize in its show-off plumage, with four long tail feathers with naked shafts tipped with expanded, lance-like vanes. Male whydahs will choose prominent perches and stake out their territories, chasing away other males but attracting females. They will launch into small flights from their perches, intended to show off their long tail feathers. At the perch, the whydah male sings its song. And even then, it will still show its waxbill-influenced youth. Although the overall song of the whydah male is indeed typical of its species, it will incorporate into this song the calls of the waxbills that reared it. Female whydahs will be attracted by these waxbill elements, recalling their own youths amidst the waxbills. So, each species of whydah will sing using the calls of the waxbill species that reared it, and so the whydah females choose mates of their own species.
A successful whydah male will mate with several females. These will then fly off and lay their eggs in the waxbill nests. The shaft-tailed whydah parasitizes the Violeteared Waxbill, Uraeginthus granatinus, one of the most beautiful of the waxbill species. The female whydah will find the waxbills by their calls that she'll recognize. She will lay several 'clutches' each season, totalling over twenty eggs in many cases. She will lay only one egg at a time, laying a typical clutch of four eggs over four days. She'll just lay one egg in each nest of her host, usually removing one of the host's eggs so the total clutch size will remain the same. But different whydah females may choose to lay their eggs in the same host nest, so that sometimes the waxbills will raise more than one whydah chick along with their own.
It sometimes happens that whydah females mis-identify whydah males and mate with one of the 'wrong' species. This confusion may cause widowfinch-whydah hybrids. In these cases the result, if the offspring is a male, is a bird that is entirely black like the widowfinches, but with the long tail feathers of the whydahs. The fact that whydahs and widowfinches can interbreed shows how closely related they are.
The shaft-tailed whydah occurs in southern Africa, reaching as far north as southern Angola and Zambia. It prefers, like its host, fairly dry, open woodland. It particularly favours savannah country dotted with hardy trees like Camel Thorns or Umbrella Thorns growing in sandy soil. It feeds on grass seeds and prefers medium-sized grasses. It needs perches for its songs and displays and is therefore absent from treeless desert or grassland. These birds move around in response to rains and droughts, but the difficulty in identifying the birds outside of the breeding season makes it hard to track their movements. The species is still quite common. Interestingly, in similar dry country in northeast Africa, there occurs a similar species, the Straw-tailed or Fischer's Whydah, which parasitizes the Purple Grenadier, a waxbill similar and closely related to the Violeteared Waxbill.
