Neotropic CormorantNannopterum brasilianumWhere and when to see them

The Neotropic cormorant is a slender, long-tailed waterbird distributed from the southern United States through much of Central and South America. In Costa Rica it occupies both freshwater and coastal wetlands, often appearing on exposed branches, posts or muddy banks. Adults look mostly black at a distance, with a small yellowish throat patch. Its ability to use rivers, reservoirs, estuaries and altered wetlands helps explain its exceptionally broad geographical range.

Size

58-73 cm (23-29 in) body length

Weight

1.0-1.5 kg (2.2-3.3 lb)

Lifespan

Not reliably established

Status

Least Concern

These cormorants frequently gather at communal roosts and breed in colonies, sometimes alongside herons and other waterbirds. Individuals alternate bouts of fishing with resting on exposed perches, where they may spread their wings. They swim low in the water and propel themselves with their feet when pursuing prey. Flights between feeding and roosting areas often follow waterways, with loose lines or small groups crossing estuaries in the morning and late afternoon. These cormorants frequently gather at communal roosts and breed in colonies, sometimes alongside herons and other waterbirds. Individuals alternate bouts of fishing with resting on exposed perches, where they may spread their wings. They swim low in the water and propel themselves with their feet when pursuing prey. Flights between feeding and roosting areas often follow waterways, with loose lines or small groups crossing estuaries in the morning and late afternoon. Wing spreading helps dry their non-waterproof feathers and aids in thermoregulation. Their colonial nesting habit provides safety in numbers from potential predators.

• Its range extends from temperate North America to southern South America.
• All four toes are connected by webbing.
• Breeding adults may show fine white facial plumes.
• It can nest in mixed colonies with herons and egrets.

Observation is possible throughout the year in Costa Rica because the species is resident. December through April often gives visitors drier conditions on the Pacific side. Caribbean rainfall patterns differ, and local water levels may affect concentrations more than the national travel calendar. Observation is possible throughout the year in Costa Rica because the species is resident. December through April often gives visitors drier conditions on the Pacific side. Caribbean rainfall patterns differ, and local water levels may affect concentrations more than the national travel calendar. Population numbers remain relatively stable year-round, offering consistent viewing opportunities. Local movements within Costa Rica may occur in response to changing water levels or food availability.

Freshwater lakes, slow rivers, reservoirs, mangrove channels and sheltered coastal lagoons all support this adaptable species. It needs accessible fish and secure resting places rather than pristine habitat alone. Nesting usually occurs in trees or shrubs near productive water. Freshwater lakes, slow rivers, reservoirs, mangrove channels and sheltered coastal lagoons all support this adaptable species. It needs accessible fish and secure resting places rather than pristine habitat alone. Nesting usually occurs in trees or shrubs near productive water. This cormorant shows a strong preference for still or slow-moving water, avoiding areas with strong currents or heavy surf. They are often found in coastal lowlands but can also inhabit inland freshwater systems at moderate elevations.

Small fish form the main diet, supplemented by crustaceans and other aquatic prey. Individuals pursue prey through the water and bring captured fish to the surface to swallow. The species can exploit shallow wetlands as well as larger rivers and lakes. Small fish form the main diet, supplemented by crustaceans and other aquatic prey. Individuals pursue prey through the water and bring captured fish to the surface to swallow. The species can exploit shallow wetlands as well as larger rivers and lakes. Their diverse diet and ability to forage in various aquatic environments contribute to their widespread distribution. Prey selection is opportunistic, based on availability in their chosen foraging grounds.

Common name

Neotropic Cormorant

Scientific name

Nannopterum brasilianum

Animal group

Birds

Size

58-73 cm (23-29 in) body length

Weight

1.0-1.5 kg (2.2-3.3 lb)

Lifespan

Not reliably established

Status

Least Concern

Identification

Compared with double-crested cormorant, it is smaller and longer-tailed, with a more pointed throat patch often narrowly edged in white on breeding adults. Compared with double-crested cormorant, it is smaller and longer-tailed, with a more pointed throat patch often narrowly edged in white on breeding adults. The bill is relatively slender, and the plumage is entirely dark, exhibiting a greenish sheen in good light. Juveniles are typically browner overall, gradually acquiring the adult's darker plumage. Look for the small, distinctive yellow-orange gular patch which is often visible.