Birds are renowned for their complex social behavior, from the rookeries of penguins to the cooperative abilities of ravens. Now the daily life of a group of sapayoa (Sapayoa aenigma) has been observed in detail for the first time, and scientists can add bisexual family communes to the list of established bird behavior.
Scientists studied two active nests of sapayoa, a species of green-yellow bird found in Panama. In one of them, they observed a family group of six and discovered that they are cooperative breeders: the two immature males helped the adult male and female feed the two chicks. They also observed one of the adult males mounting a younger male and one younger male mounting the other, an unusual behavior that might be associated with social dominance.
These are not the only unexpected behaviors the scientists found. The young males sometimes arrive at the nest with food, but don't feed the young, occasionally eating the food themselves.
“This could represent ‘fake-feeding,’ when birds bring food to the nest to appear like team players, but sneakily eat it themselves. It’s also possible that the young males were simply balancing the needs of the chicks with their own hunger. Clearly, there is much still to learn,” said Sarah Dzielski, lead author of the study, in a statement.
The sapayoa’s closest relatives are not in the Americas but in Asia and Africa, where over 50 species form a group called Old World suboscines. The paper, published in The Auk: Ornithological Advances, highlights important connections between birds from the Old and New World. Just like the sapayoa, suboscines are also cooperative breeders and build pear-shaped hanging nests.
“The Sapayoa is so different from other passerine birds that it is currently placed in its own family, Sapayoidae, but relatively little is known about its natural history,” added co-author Benjamin Van Doren. “This gap in scientific knowledge was the reason we traveled to eastern Panama to learn about this enigmatic species. We hoped that more information about the Sapayoa’s natural history would cast its surprising evolutionary relationships in a new and clearer light.”