We screened the largest video database of displaying birds of paradise (The Macaulay Library of the Cornell Lab of Ornithology) and found videos showing matings between female-plumaged individuals! This phenomenon has only been described a handful of times in the wild, once in the 1980s in Goldie’s Bird of Paradise and again in the 1990s in Lawes’ Parotia.

While many of the cases we observed were likely matings between adult females, which is generally rare in birds, in one species—the Magnificent Bird of Paradise—we think they are most likely performed by immature males. These young males look like females until they are old enough to grow their characteristic ornamental feathers, and may aggressively try to mate with females that are being displayed to by adult males.

While we weren’t able to verify this hypothesis, as we couldn’t tell the birds’ sex, our study represents some of the best evidence to date of alternative mating tactics in the birds of paradise!

The journal Ethology will also feature this spectacular shot by photographer Dustin Chen on the front cover of their upcoming issue! You can read the paper following this link.