Scarlet-thighed Dacnis

How to find it

Look for it at fruiting trees and bushes, both at the forest edge and inside the forest. It tends to stay high in the canopy at forest edges, and pairs often follow mixed feeding flocks, so a scope helps. A 2024 birding tour got good scope views at Tayutic Mountain Reserve and along the Río Tuis. A local guide sees it often in foothill and middle elevation sites up to about 1,500 m on the Caribbean slope. Watch for it in clearings with scattered fruiting trees too.

How to recognise it

The male is the easy one.

He is mostly black below, with a turquoise-blue head, back and shoulders and a red eye. His black underparts join up with a black eye mask. The red thighs are hard to see in the field, so do not count on them as a field mark.

The female is less showy. She has a turquoise face that contrasts with a buffy belly, and she looks pale creamy beige below.

Young males can show some light on the belly and black on the throat and chest, so they may look different from adult males.

It is a small bird, about 11 to 12 cm long, and weighs roughly 15 to 17 g, so it can vanish among leaves in the canopy.

Behaviour and diet

This is a social bird. Groups of up to 15 can be found, and it joins mixed-species foraging flocks. In Costa Rica it usually travels in pairs or small groups, often with tanagers, honeycreepers and warblers.

It is very active and always on the move while feeding. It tends to stay high in the canopy at forest edges, and pairs often follow mixed feeding flocks. Breeding season is not fully known but seems to run from at least March to July. The nest is a shallow hammock-like bowl slung between two thin branches, 12 to 15 m up.

Where it lives

In Costa Rica it ranges from about 400 to 1,500 m on the Pacific slope. On the Caribbean slope it is found between about 1,300 and 1,500 m. A Costa Rican source describes it as resident on the Caribbean and southern Pacific mountain slopes, from about 500 to 1,500 m.

It forages in fruiting trees, often well away from the forest itself, in clearings with scattered trees. A Costa Rica field guide says it is locally common on the Caribbean side of the Cordillera Central and Cordillera de Tilarán, and is found in smaller numbers north to Volcán Miravalles.

When to see it

A local guide says it moves down into the lowlands during the dry season. After breeding it may wander widely in small flocks, often moving down from its usual elevation to find fruiting trees.

Similar birds

The male looks a bit like a Blue Dacnis but has mostly black underparts. On a Costa Rica tour, Blue Dacnis was seen alongside it at the same sites, which allowed side-by-side comparison. A birder also reported both in one fruiting tree near Dominical, together with Green Honeycreeper and several tanagers.

Names and lore in Costa Rica

In Costa Rica the bird is called Mielero Celeste y Negro. A common nickname is Calzones Rojos, which means red pants and refers to the red thighs. Costa Rica is the only country that uses Mielero Celeste y Negro; Colombia uses Dacnis Negriazul, and Ecuador and Panama use Dacnis Musliescarlata.

Status and conservation

The AOCR list marks it as a resident (R), the IUCN lists it as Least Concern, and it is considered fairly common in Costa Rica.

Photography tips

It stays in the highest canopy layers, which makes it a challenge to spot. Look for it around fruiting trees at forest edges. In Panama it was seen fairly regularly in fairly open, sunny places with fruiting trees, so sunny clearings with fruit are worth a wait.