Red-legged cormorants Phalacrocorax gaimardi

Red-legged cormorants (RLC) are conspicuous seabirds in the Humboldt Current. In Peru, they are mostly a solitary, cliff nesting seabird. Three basic features are associated with the choice of nesting sites: vertical walls (either in open cliffs, sea caves or islets), rocky substrate and the presence of the sea below their nests. The southern and central coast of Peru (from Morro Sama to Chimbote) held more RLC (90%) than the northern coast (10%). Because of the inaccessibility of their nesting sites, main colonies (Bufadero in Moquegua and La Chira in Camana) are located in unprotected areas in the coast. A population size between 1600 and 2000 birds has been estimated for Peru in 1999-00 (Zavalaga 2001). Breeding is asynchronous and the onset of egg laying varies according to the locality. No information on its breeding and foraging ecology are available in Peru, but detailed studies on these subjects has been carried out in Argentina where selective pressures are quite different to those found in Peru.

RLC have undergone a spectacular decline over the last 30 years. Between 1968 and 1999-00, the numbers at ten localities in the northern and central coast decreased from 3229 to 69 birds. El Niño 1997-98 also affected the population size, as numbers prior and after this event at eight southern localities decreased by 73%. Because the inaccessibility of their nesting sites and the lack of ground predators, RLC are apparently not in danger on land. However, entanglement in fishing nets, competition for food in inshore waters, pollution, human disturbance and harvesting of kelp gulls are potential threats at sea.