Black-crowned Night Heron

How to find it

Look at dusk and after dark, when birds come to the water's edge to feed. By day, scan the shaded roosts in swamps, waterside forest and mangroves. Boat trips are the usual way in: Isla Pájaros tours usually leave from the town of Bebedero, and some are tailored for birders. The Tárcoles River boat trip near Carara searches estuary and river edges, where it is sometimes seen with Yellow-crowned. Boat trips in the northern lowlands have produced it too, though one Field Guides tour found fewer than 10 per trip. Check the edges of other heron groups, where it is often found.

How to recognise it

Adults have a glossy black crown and back, pale gray wings and tail, and a white face, neck and underparts.

The eye is red, the bill is mostly black and the legs are yellow. The overall shape is stocky and big-headed, about 64 cm long.

In the breeding season adults grow a long white plume at the back of the head, and the legs and facial skin become more brightly colored.

Young birds look quite different. They are brown above with buff or white streaks and have yellow eyes. Their underparts are whitish with brown to blackish streaks.

What it sounds like

Recording: Christoph Moning, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It roosts by day and hunts at night, appearing at the water's edge. Its prey includes fish, frogs and some rodents.

Birds gather to sleep or rest together. In Costa Rica it is often seen with scattered groups of other herons, or at the edge of flocks of other species such as Snowy Egret.

It nests on a stick platform in a tree, usually at the high end of a branch hanging over water, and lays 2 to 4 pale turquoise-blue eggs. Breeding runs from late in the rainy season to early or mid dry season.

Where it lives

It lives in swamps, gallery forest along waterways and mangroves, and it prefers freshwater habitats.

It is common at some sites in the northern Pacific lowlands. In the Caribbean lowlands and foothills it is widespread but usually uncommon and local, and in the Central Valley it is quite rare.

Known nesting sites are in the Tempisque plain, on Isla San Pablo and Isla Pájaros. It probably nests at Estero Madrigal too.

When to see it

Winter visitors are present from October to March, alongside year-round residents. At Estero Madrigal it is abundant in the dry season, and many waterbirds at Palo Verde are migrants arriving in the dry season.

Similar birds

Young Yellow-crowned Night Heron looks similar but is more spotted and less streaked, with an orange eye and a thicker bill. For young birds the bill is the best clue: the yellow-crowned immature has a thick, all-black bill and smaller pale spots on the wing coverts, while the young Black-crowned has a slimmer bill with a light base. Adult Yellow-crowned birds have a creamy-white crown and cheek patch, so adults are easy to tell apart. The Black-crowned call is lower in pitch.

Names and lore in Costa Rica

The AOCR name is martinete coroninegro (chocuaca). Costa Rican sources also call it chocuaco and martinete capinegro, and the names huaco, guaco and chocuaca imitate its call.

Status and conservation

The AOCR list marks it as R,M, a resident with migrants as well, and a study of Costa Rican herons lists it among the species that breed in the country.

Photography tips

The dry season is best for waterbirds at Palo Verde. Water drops, birds crowd around the remaining marshes, and there is little leaf cover to block views of roosting birds. On the Tortuguero river a visitor photographed night herons watching from perches on branches.