Summary: The whydahs Vidua and Cuckoo Finch Anomalospiza imberbis are brood-parasitic finches that use other species of birds to rear their young. Whydahs use estrildid finches; Cuckoo Finch use the grass-warblers Prinia and Cisticola. The whydah males in breeding plumage have long tails, the females are streaky brown birds, and the juvenile plumage often closely resembles the host young. Most whydahs mimic the songs of their host species. The songs are helpful in identifying the species of paradise whydahs in West Africa, but the male breeding plumages are more distinctive; females also can be distinguished. Cuckoo Finches are not known to mimic host song. Males change from season to season due to wear in plumage from streaked dark brown to unstreaked yellowish above, females are similar to Euplectes bishops, and the young resemble the plumage of the host young.