First report of egg predation by an unpaired Eurasian Coot, Fulica atra, L., 1758 (Aves: Gruiformes) on Black-winged Stilt, Himantopus himantopus, L., 1758 (Aves: Charadriiformes): one case from central Italy

The Eurasian Coot, Fulica atra, is a gregarious Palearctic rail that only rarely occurs singly. Even if resident birds can present territorial behaviour all through the year, most aggressions are developed during the breeding season, and the scientific literature has reported inter- and intraspecific attacks by Coot breeding pairs. Unpaired individuals do not usually show any territoriality and are often subjected to attacks by breeding pairs. It is, however, possible to observe unpaired Coots defending a territory before pairing, but the typical aggressive behaviour is developed after the beginning of nest building. Egg predation by Coots is reported as a rare phenomenon, exerted only by members of breeding couples. In this note, we report two predation cases exhibited by an unpaired individual against nests and eggs of Himantopus himantopus. We discard the hypothesis of competition for food between these two species and suggest that this peculiar behaviour could have been induced by endocrine hormonal secretions, regardless of whether the individual was paired or not. © 2013 Copyright Unione Zoologica Italiana.