Mangrove Yellow Warbler

How to find it

Check mangrove edges and adjacent coastal scrub, and listen for the chip calls. At Chomes, Puntarenas, a bird moved between mid-height perches at the edge of medium-sized mangroves, so scan that middle layer. A boat tour in Puntarenas has also produced a record. Near Tarcoles, searching for Mangrove Hummingbird led one group to a male, so that search can pay off for both birds. Migrant Northern Yellow Warblers are in Costa Rica from about September to early or mid May, so check any male for the chestnut hood.

How to recognise it

Adult males are bright yellow with a chestnut hood or crown. On mainland populations the hood covers the whole head. Males from Mexico to Costa Rica have a crisply edged hood and only sparse, thin streaks on the chest and sides.

The bird is about 12.5 cm long. Juveniles are dull and greyish. Females are variable, from bright yellow to grayish, and can show a small rusty crown spot. In Costa Rica the mangrove form has only light streaking on the chest, and some individuals show no rusty crown patch at all.

What it sounds like

Recording: Eliezer Nieves-Rodriguez, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It eats mainly insects and spiders, picking them from shrubs and branches or darting out from a perch to catch flying insects. It forages mostly in the canopy, but also lower down and on the ground.

Birds are territorial all year and usually alone, sometimes in pairs in the breeding season. Both sexes sing, which is unusual among warblers. A student study of mangrove warbler foraging was carried out along the Rio Cuajiniquil in Guanacaste.

Where it lives

This warbler is largely restricted to coastal habitat at or near sea level, and it also uses coastal scrub next to mangroves. In Costa Rica it is a common resident of Pacific coast mangroves from the Gulf of Nicoya southward, and it seems to be missing from the outer part of the Nicoya Peninsula.

Caribbean coast records are unconfirmed. Costa Rican birders know of no documented bird there, though Panama is very close.

When to see it

It is a non-migratory resident that sings all year, so it can be found in any month. On the Pacific coast courtship starts in early March and breeding ends in late August, with May and June the peak nesting months.

Similar birds

Migrant Northern Yellow Warblers are common in winter in lowlands on both slopes, including mangroves, arriving in September and October and leaving by early to mid May. Resident females look the same as these migrants, and only the resident male's reddish-brown cap marks him out. The migrant is smaller and rarely shows rufous on the head. A yellow warbler without a chestnut hood in that window may be a migrant, while a hooded male is a resident.

Names and lore in Costa Rica

Costa Ricans call this bird cazadora, cazadorcilla or reinita de manglar. The name reinita amarilla is also used in Costa Rica, a name shared with the migrant Northern Yellow Warbler.

Status and conservation

The AOCR lists it as a resident (R), and the IUCN lists the species as Least Concern.

Photography tips

Work the edge of the mangroves, where a singing male at Chomes moved between mid-height perches. Listening for the chip calls helps you find the bird before you see it.