Buff-rumped Warbler

How to find it

Look along watercourses, wet patches of forest floor and temporary puddles on forest paths, where it forages. Listen first, because the loud, piercing call often gives it away. A birder at Quebrada Gonzalez found it by song at 6:20 AM, yet the birds stayed hidden in thick undergrowth, so slow, careful checking is needed. In the Sarapiqui area, scanning the river from a boat or from the Chilamate bridge gives a good chance. Because it nests on sloping banks beside paths and streams, a guide at Arenal was not surprised to find it on the trail, fanning its bright tail to startle insects. One pre-breakfast walk along the Sardinal River trail at La Fortuna found it at the river edge beside a Louisiana Waterthrush.

How to recognise it

This is a small warbler, about 13.5 cm long. Look for these marks:

Crown: slate-gray.

Face: a buff eyebrow stripe and a dark line through the eye.

Underparts: whitish with a buff wash.

Rump and base of the tail: tawny-buff.

Outer half of the tail: blackish, which contrasts with the buff rump and shows well when the bird fans its tail.

Juveniles are browner above than adults, including on the face. They have dull buff wing bars and a dull buff chest and sides, so they look quite different from the adult.

What it sounds like

Recording: Tommy Andriollo, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

Singles and pairs hop on the forest floor and along fallen logs, constantly pumping and wagging the tail. It eats mainly insects and other invertebrates, and in Costa Rica it often follows army ant swarms to catch the insects they flush.

At Tapanti, several pairs flicked through trees along the park road, curtsied on branches and leapt out after prey in short aerial sallies. Pairs hold a long, narrow territory along a stream all year. The nest is a bulky dome with a side entrance, usually on a sloping earth bank by a stream or path. Breeding in Costa Rica spans at least April to August.

Where it lives

It lives in forest and is always found close to water. In Costa Rica it ranges from sea level to about 1,000 m on the Caribbean slope and about 1,500 m on the Pacific slope.

A Costa Rican source calls it a common resident of the Caribbean lowlands and the southern Pacific. It can turn up along almost any river or stream in humid forest, and it seems to favour dark, shaded streams where the bright rump stands out.

When to see it

A birder reported that birds at Hitoy Cerere were fairly common and called often during March and April.

Similar birds

The Caribbean slope form has a flaring white eyebrow, dark legs, dark spotting on the breast and a much paler buff rump, which sets it apart from the Pacific forms. At Tapanti, a tour group used the flaring white eyebrow and buffy flanks to tell it from a similar bird. The pale rump and side-to-side tail swing make it eye-catching along waterways.

Names and lore in Costa Rica

Costa Ricans call it Reinita Guardaribera. Other Spanish names elsewhere in its range include Arañero Ribereño and Reinita Lomihabana.

Status and conservation

Listed as a resident (R) on the AOCR list, rated Least Concern by the IUCN and described as common in Costa Rica.

Photography tips

Expect dim light. One photographer found the bird always in shadow along a forest trail, which made good photos hard. A shot at the Arenal hanging bridges used a 600mm lens with a teleconverter and a very high ISO, with no flash. Plan camera settings for low forest light.