Birds · Suliformes · Phalacrocoracidae

Guanay Cormorant

Leucocarbo bougainvilliorum

Near Threatened

It could become endangered in the near future if current threats go unchecked. See full glossary

The Guanay cormorant is the guano bird par excellence and one of the most important in the economic history of Peru. It breeds in extremely dense colonies on the islands of the Humboldt current, where it builds up guano layers tens of metres thick. Its food is almost exclusively the Peruvian anchoveta, and its population swings brutally with El Niño events, which collapse the biomass of that fish and cause mass die-offs.

Weight

1.8 kg – 2.5 kg

Size

71 cm – 76 cm

Lifespan

15 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Diurnal

Active mainly during the day.

Social structure

Colony

Lives in large concentrations, often for breeding reasons.

Sighting difficulty

Moderate

DesertOceanIslandsCarnivore Diurnal Colonial Near Threatened Bird Desert Ocean Islands

2countries 4parks 2dive sites12same family

Fun facts

Its droppings, accumulated over centuries, formed guano layers more than thirty metres thick on the Peruvian islands, a fertiliser so valuable that in the 19th century it sustained the national economy and caused international conflict.
Its population has fallen from tens of millions of birds at the start of the 20th century to a few million: the industrial anchoveta fishery competes directly for its only food.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (bird)
Habitat & environment: Guano islands and rocky coasts of the Humboldt current, in Peru and Chile
Sexual maturity: 3 years
Gestation / incubation: 30 days of incubation
Litter / clutch size: 3 eggs

Sources consulted: https://www.iucnredlist.org/ | https://animaldiversity.org/ | https://es.wikipedia.org/