Viduidae – Whydahs and indigobirds

These birds are best known for two striking traits: the males’ extravagant breeding plumage and their remarkable strategy of brood parasitism. Instead of building their own nests and raising their young, Viduidae species lay their eggs in the nests of other small birds, mainly waxbills and other finches. Their hosts unknowingly incubate the foreign eggs and raise the whydah or indigobird chicks as their own, allowing these little parasites to devote more time to mating displays and territorial defense.

Indigobirds, such as the village indigobird, are typically small, stocky, and dark-colored, often appearing glossy black, blue, or green depending on the light. Whydahs, like the pin-tailed whydah and the long-tailed paradise whydah, are similar in size but spectacularly adorned during the breeding season, with males growing long, flowing tail feathers that can make them seem two or three times their body length. Outside of the breeding season, both males and females are much plainer, sporting modest brownish tones that help them blend into the grasslands and savannas they inhabit.

One of the most fascinating aspects of Viduidae biology is their song mimicry. Male indigobirds and whydahs mimic the songs of their specific host species, a trick that not only helps them choose mates from the correct “imprinted” group but also deceives host birds into accepting the parasitic chicks. Young birds imprint on the songs of the species that raised them, ensuring that the cycle of mimicry and parasitism continues across generations.

Despite laying their eggs in the nests of others, Viduidae chicks have evolved to look and sound very much like the host chicks, perfectly mimicking their begging calls and feather patterns to avoid detection by foster parents. Unlike some other brood parasites, like cuckoos, whydah and indigobird chicks don’t eject their nestmates; instead, they blend in and are raised alongside true host offspring.