Guanay Cormorant

The Guanay Cormorant is a striking black-and-white seabird of the cold, nutrient-rich Humboldt Current off Peru and Chile. It has glossy black upperparts, a white throat, chest, and belly, and bare reddish-pink skin around the base of the bill and eye. Its bright pink feet add a further splash of color to its otherwise bold pied plumage.

Historically, its enormous breeding colonies on offshore islands produced vast deposits of nitrogen-rich droppings, or guano, which fueled a major 19th-century fertilizer industry along the Peruvian coast.

Key field marks

• Glossy black upperparts contrasting sharply with white underparts and throat
• Bright pink feet
• Reddish-pink bare skin around the bill base and eye
• Long neck and slender bill

Similar species

• Neotropic Cormorant is entirely dark with no white underparts.
• Red-legged Cormorant is smaller and more uniformly slate-grey.
• The bold black-and-white pattern combined with pink feet is distinctive among South American cormorants.

Habitat

Strictly marine, associated with the cold, highly productive waters of the Humboldt Current, breeding on rocky offshore islands and coastal cliffs.

Range

Found along the Pacific coast of South America, primarily Peru and Chile.

Migration

Mostly sedentary, though it may shift locally or irrupt in response to El Nino events that disrupt local fish stocks.

Behavior

Highly colonial and gregarious, often seen in immense flying columns streaming along the coast between roosting islands and feeding grounds.

Voice

Largely silent at sea; utters guttural croaks at breeding colonies.

Feeding

Feeds almost exclusively on anchoveta and other small schooling fish, caught by diving, often in massive cooperative feeding flocks.

Nesting

Breeds in extremely dense colonies on guano islands, building simple nests of guano and debris; typically lays 2-3 pale blue eggs.