Gray-rumped Swift

How to find it

Look up for small flocks flying low over forest, open country or waterways in the wet lowlands. They fly low enough to show the dark body and pale rump well. Across the species in general, birds usually fly over forest and drop lower over clearings and rivers, which gives better views. In the morning and evening they often fly low over roads or clearings. At midday they rise high above the forest, often mixed in with other swifts. A boat trip on the Tortuguero canals is one good way to meet them.

How to recognise it

This is a small, dark, stub-tailed swift. Across its range the field marks are easy to list:

A glossy black back.

A clearly pale gray rump.

Lighter gray underparts.

Wings that bulge in the middle.

A short, square tail.

It measures about 10.5 cm and weighs about 17 g, and males and females look alike. The pale rump is the mark to look for first. In Costa Rica these swifts fly low enough to be seen as dark, nearly black birds with a well-marked pale rump, which makes them easier to study than many swifts.

What it sounds like

Recording: Niels Krabbe, CC BY-SA 4.0, source, read 5 Nov 2026.

Behaviour and diet

Gray-rumped Swifts feed on flying insects, including flying ants, bees, wasps, beetles and flies, and they are seen in flocks of about 20. The flight is rapid and direct, with quick wingbeats. Across the species' range it nests on the vertical inner wall of a chimney or similar structure, in a half-cup nest, and both parents incubate at night.

Where it lives

In Costa Rica this is a bird of the humid Caribbean lowlands, from sea level to roughly 600 m, in valleys and on slopes. It is also described as easy to see at Caribbean foothill sites. Across its whole range, which is a wider picture than Costa Rica alone, it uses lowland evergreen forest, secondary forest and mountain areas, and occurs from sea level to about 1,800 m.

When to see it

In Costa Rica the breeding season is given as March to July.

Similar birds

Costa Rican Swift also has a pale gray rump, but it lives in the southern Pacific lowlands and slopes, while Gray-rumped is the Caribbean slope species. Chimney Swift is uniformly colored and only passes through Central America on migration. Vaux's Swift is a northern migrant with a paler throat and rump, while the Gray-rumped's rump is more clearly delineated. One author's impression, not a firm field mark, is that the Gray-rumped's wings seem shorter than a Chimney Swift's.

Names and lore in Costa Rica

The official Costa Rican list gives Vencejo Lomigrís as the Spanish name. Another Costa Rican list spells it Vencejo lomigris, without the accent.

Status and conservation

The official Costa Rican list marks it as a resident (R), and across its range it is one of the commonest Chaetura swifts, with no immediate threats known.

Photography tips

These swifts fly low enough to show that they are dark, nearly black, with a well-marked pale rump, so they are easier to study than many swifts. Over clearings and rivers they drop lower, which gives better views.