Thick-billed Euphonia

How to find it

Start with open, edge and garden settings, since it is more likely outside forest than other Costa Rican euphonias. Look in gardens and flowering plantings around lodges, and at fruit feeders. Because it is often in semi-urban settings, it can be seen at fairly close range. Scan tanager-led mixed flocks and watch for pairs or small groups. Listen for a rambling song full of borrowed notes. On a trip we build in the south, Coto Brus is a good area to try.

How to recognise it

The male is glossy dark blue above with bright yellow underparts, including the throat. A yellow forecrown patch reaches to just behind the eye, and that long cap is the mark to watch.

The female is dull olive above and yellow below, with an olive wash on the breast. Both sexes have dark legs.

It is tiny, about 10 cm (3.9 in) long and roughly 13 to 16.5 g. The bill is thicker than in other euphonias, but that is of very little use in the field, so rely on plumage pattern instead.

Immature males darken on the head before their back changes colour, and blue areas can look black in poor light.

What it sounds like

Recording: Francis Pérez, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

It is usually seen in pairs or small groups, and it often joins mixed flocks, especially ones led by tanagers. It eats mainly mistletoe fruits and other small fruits, with a few insects added. That fondness for fruit explains why feeders and flowering plants draw it. Elsewhere in its range it regularly comes to fruit feeders, where it shares space with tanagers and other birds.

Where it lives

In Costa Rica the Central American form lives on the Pacific slope, starting in Guanacaste and continuing south into Panama. Here it reaches about 1,100 m (3,600 ft) in elevation.

Across its range it is mostly found below 1,200 m in secondary woodland, forest edges, scrubby clearings and gardens. It is one of six euphonia species recorded around Coto Brus in southern Costa Rica.

When to see it

Breeding is documented between March and September in Panama, and it probably breeds in the same window in Costa Rica.

Similar birds

For a yellow-throated male euphonia, check the cap. Thick-billed has a long yellow cap that passes the eye, while Yellow-throated has a short cap that stops at the eye, and Thick-billed is the more common of the two in the southwest. A blue throat points to a different species. The male Yellow-crowned has a blue-black throat and yellow over the whole front and top of the head. Females of Thick-billed, Scrub and Yellow-crowned all have entirely greenish yellow to yellow underparts, while the female Yellow-throated has a pale throat, pale belly centre and yellow flanks.

Names and lore in Costa Rica

Costa Rican Spanish uses Eufonia piquigruesa. A checklist site also lists Agüío and Güere as Costa Rican names, tagged as Huetar. Elsewhere in its range it is also called calandria piquigruesa, curruñatá piquigordo, fruterito de pico grueso and eufonia gorgiamarilla.

Status and conservation

Listed as a resident (R) on the AOCR list, it is uncommon in Costa Rica and rated Least Concern globally by the IUCN.

Photography tips

Look in gardens and flowering plantings around lodges, and at feeders. Because this euphonia is often outside forest and in semi-urban settings, it can be seen at fairly close range, which suits photography.