Guanay cormorant

How it lives

Guanay cormorants breed in dense colonies on offshore islands and headlands. Nests are built of guano on flat ground, at densities of up to about three per square metre. Pairs lay two or three eggs. Breeding can happen all year, with peaks in November and December. The species is the main producer of guano, the seabird droppings once prized as fertiliser. Incan law protected nesting birds, and Peru still protects guano islands today.

Where it goes

Guanay cormorants live along the Pacific coast of Peru and northern Chile. After breeding they spread south to southern Chile and north to Ecuador. In El Niño years, when food runs short, they have been recorded as far north as Panama and Colombia.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

IUCN lists the species as Near Threatened. The population was estimated at about 3 million birds in 1984 (some sources say 3.7 million). It has since fallen by about 30 percent, linked to competition with fisheries, bycatch, and habitat loss. A study at Punta San Juan reports further declines from avian influenza in 2022 to 2023 and from El Niño in 2023 to 2024, without giving a total. After the January 2022 oil spill off Lima, guanay cormorants were among the most affected species. Peru's wildlife service SERFOR recorded 1,852 dead wild animals of 28 species, but the exact total is unknown.