Hooded Merganser

How to find it

Do not plan a trip around this bird, because it is a mega rarity here. If you scan lakes and ponds, check quiet water with trees at the edge, since the species favours wooded water elsewhere. Look along the back edge of the water and be patient, because it dives often. Check any Wood Ducks you find, as it shares many sites with them. Lake Arenal, near Nuevo Arenal, is where the second national record was found. If a stray turns up, local birders are the people who learn of it first.

How to recognise it

This is a small duck, about 40 to 49 cm long, with a thin, serrated bill built for catching fish. Both sexes have a crest that can be raised or lowered.

The breeding male is mostly black and white. He has a white, fan-shaped crest edged in black, with large white patches on each side, a black body with chestnut flanks, and a white breast marked by two vivid black vertical stripes.

Females and young birds are greyish-brown with a reddish-brown crest.

In the non-breeding season the male looks much like the female, but his eyes are yellow and hers are brown.

These details describe the species across its range. Both Costa Rican records were single lost birds, and the Lake Arenal bird was a female, so the brown, crested female plumage is the one to know.

What it sounds like

Recording: Richard Littauer, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It hunts by diving and chasing prey underwater by sight. Fish make up most of its diet, along with crustaceans and aquatic insects.

Away from Costa Rica it often stays along the back edge of the water and dives often, which makes a quiet bird easy to lose. It shares many sites with Wood Ducks, and it nests in tree cavities.

Where it lives

Across its range it uses wooded ponds, lakes, rivers and streams. It breeds in southern Canada and the northern and western United States. In winter it favours wooded freshwater wetlands, lakes, rivers, estuaries and tidal creeks, and seldom visits salt water. Most birds winter in the southern United States and northern Mexico, so Costa Rica lies well south of the normal range. In Costa Rica the two records come from the Caribbean-slope foothills at Pocosol and from Lake Arenal in the north.

When to see it

The second Costa Rican record was found on 16 May 2020. That is unusually late, and very unexpected, for a bird that normally winters no farther south than northern Mexico.

Similar birds

The female can be confused with a female Red-breasted Merganser, which is also on the Costa Rican list as accidental. The Hooded has a shorter bill and neck. Its crest is a warmer tone that contrasts with the duller brown of the head and body.

Names and lore in Costa Rica

The official Costa Rican list gives the Spanish name Serreta Capuchona, with Pato de Cresta (crested duck) as the alternate name. Other Spanish names for the species include Serreta de Caperuza and Serreta Capuchino.

Status and conservation

The official Costa Rican list codes the Hooded Merganser A, accidental, while its global status is Least Concern.