Sociable weavers on a killing spree

These Southern African birds commit infanticide - for no known reason

- Richard Pallardy

THEY BUILD THE LARGEST COMMUNAL bird nests in the world but the avian societies of sociable weavers (Philetairus socius) are far from utopian. New research published in the journal bioRxiv shows that the Southern African birds regularly commit infanticide, the intentional killing of a hatchling or immature animal - in this case often unrelated nestlings.

“They usually peck the chicks on the head to kill or weaken them, then throw them out of the nest. Very small chicks they just throw out,” says lead author Rita Covas, a behavioural ecologist and evolutionary biologist at Portugal’s University of Porto.