Yellow-bellied Siskin

How to find it

Start with the oak forests and the clearings beside them, and scan the canopy and treetops for perched flocks. Listen for the thin, high calls before you see the birds.

Feeders with fruit are worth your time: a group in the Savegre Valley in March 2024 saw siskins feeding heavily on fruit at a restaurant's feeders. Birders also record it along the Cerro de la Muerte highway and on the Providencia Road, a rural road through highland forest near the entrance to Los Quetzales National Park.

Because flocks move long distances, expect to revisit a spot rather than rely on one stop.

How to recognise it

This is a tiny finch, about 10 to 11.5 cm long and 11 to 14 g in weight. Males and females look clearly different, and those size and plumage details are given for the species across its whole range.

Adult males: glossy black on the head, chest and back; a bright yellow belly; yellow at the base of the wing feathers; yellow on the sides of the tail.

Females: dull olive above; olive-yellow below.

Both sexes show a broad yellow wing band. In humid montane forest the male is the only boldly black and yellow siskin, so a small black and yellow bird in the treetops is a good place to start.

Behaviour and diet

Across its range, flocks of up to 30 birds feed together in remote or protected areas. They search treetops for small insects and oak flowers, and sometimes drop to open ground for seeds. Males sometimes sing in groups.

In Costa Rica, large flocks perch on treetops in remote areas, and males sing together there outside the breeding season. The species moves long distances and rarely stays in one place for long, except when nesting, so a flock that is present one day may be gone the next.

Where it lives

In Costa Rica it is found from about 1,800 m up to the treeline. It frequents the canopy of oak forests and nearby clearings, and sometimes uses secondary growth or pastures some distance from the forest.

Across its whole range it uses humid forest, forest edges and clearings, coffee plantations and shrubby areas, and is recorded from 800 to 3,000 m. It breeds in mountain oak forest and forages in clearings and other edge habitats.

The Costa Rican range runs from the Cordillera Central into western Panama. It is very uncommon to scarce in the Central Volcanic range and northern Talamanca.

When to see it

In the northern part of its range, which includes Costa Rica, it breeds from March to May, and a Costa Rican source gives April to May for nesting. Eggs are laid in April or May in a shallow cup nest of rootlets, bark and lichen, set 2.4 to 3.7 m up in dense foliage of a small tree in a clearing.

Similar birds

The Lesser Goldfinch, which also lives in Costa Rica, looks similar, but it is paler, has a white wing patch and a more musical song. Male siskins differ by a black throat and upper chest. The siskin is more of a woodland bird. At higher elevations it overlaps with the Black Siskin, which lacks the extensive yellow underparts.

Names and lore in Costa Rica

The Costa Rican bird list gives the Spanish name Jilguero Vientriamarillo and a local alternate name, Mozotillo de Montaña. Another Spanish name used for the species is Jilguero Pechinegro, which means black-breasted siskin.

Status and conservation

The AOCR lists it as a resident (R), sources describe it as fairly uncommon in Costa Rica, and IUCN lists it as Least Concern.

Photography tips

Perched flocks on treetops in clearings give you the clearest views, so scan the canopy edge in good light. Fruit feeders in the Savegre Valley have drawn siskins close, which is a good setting for a steady look at both sexes.