Social structuring at a communal roost of Choughs Pyrrhocorax pyrrhocorax

The social structure of a communal roost of Choughs Pyrrhocorax pyrrhocorax was studied between July and September 1985. Different age classes within the roost were spatially segregated. Third-year birds were significantly more likely to attack another Chough and roosted in the densest part of the roosting flock. First-year birds roosted significantly lower down the roost cliff and on the periphery of the flock.