The
Peruvian Diving-petrel is and endangered seabird in Peru. Nesting sites are
restricted only to Isla San Gallan and Isla La Vieja on the central coast of
Peru. The population size for both islands has been estimated between 12,200 and
13,300 birds in 1996 (Jahncke and Goya 1998). It is also the largest of the four
extant diving-petrels and can be found from isla Lobos de Tierra in northern
Peru to Corral in Chile. It nests in burrows in salt crusts and sandy substrate.
There are two breeding seasons in a year: the first from December to April and
the second from May to October (Jahncke and Goya 1998). This small bird weighs
in average 200 g, but their diving capabilities are remarkable. The mean maximum
dive depth attained for 22 adults was 32 m, but the deepest dive was 83 m! This
maximum dive depth was 81% deeper than that expected (46 m) by its body size and
the deepest reported for a seabird weighing less than 210 g (Zavalaga and
Jahncke 1997). They consume small crustaceans, mainly euphausiids and larval
stages of Peruvian anchovies and other fishes.
Main threads include poaching of adults and egg collection by guano workers (every five to seven years) in La Vieja Island and by fishermen in San Gallan Island. Possible competition with commercial fisheries deserve future research.