The red-collared widowbird (Euplectes ardens) is a species of bird in the family Ploceidae. Red-collared widowbirds are found in grasslands and bush clearings in Eastern and Southern Africa. They are known for their long tails and brilliant red badges, both which act as sexual ornaments. They are often associated with other widowbird and bishop species. They are polygynous, where males acquisition of territory is an important determinant in their access to mates. Red-collared widowbirds have a wide range and there is little concern in terms of conservation status.
Similar to other widowbirds, male red-collared widowbirds have both seasonal and sexual dimorphism. Males are about 25 cm in length while females are only 13 cm. During non-breeding seasons, the male plumage is brown, while in breeding season, October to April, they have black plumage with a long tail, approximately 22 cm, and crescent-shaped carotenoid based chest patch. There is significant variation in brightness, hue, and chroma of the carotenoid badges. In contrast, females and subadults, like nonbreeding males, are streaky dull brown with a short tail, approximately 4 cm. Nonbreeding males, however, retain their black tails, while females and subadults' tails are dark-brown.