Yellow-thighed Brushfinch

The Yellow-thighed Brushfinch, scientifically known as Atlapetes tibialis, is a passerine bird that is not a true finch despite its common name. It belongs to the family Passerellidae, which includes American sparrows, juncos, and towhees. This species is characterized by its long tail and a body length of 18.5 cm, weighing approximately 31 g. Adults display a predominantly dark grey plumage with a black crown, throat, wings, and tail. An olive tinge graces the belly and breast, while the bright yellow thighs offer a striking contrast and are the bird's namesake. Juveniles exhibit a duller, sootier plumage with brownish underparts and olive-brown thighs.

Identification Tips

When identifying the Yellow-thighed Brushfinch, look for the distinctive bright yellow thighs that stand out against the darker plumage. The adult's black crown and throat are also key features, along with the olive tinge on the belly and breast. The bird's long tail and overall dark grey coloration are additional identification markers.

Habitat

This bird is commonly found in the wet mountain forests, second growth, bamboo clumps, scrubby pasture, and bushy clearings. It thrives at altitudes ranging from 1700 meters up to the timberline.

Distribution

Endemic to the highlands, the Yellow-thighed Brushfinch graces the landscapes of Costa Rica and western Panama.

Behaviour

Outside of the breeding season, the Yellow-thighed Brushfinch may descend to 1200 meters on the Caribbean slopes. It is often seen in pairs or family groups and may join mixed-species feeding flocks with other small birds such as warblers. Notably approachable, this bird exhibits a curious and engaging demeanor.

Song & Calls

The vocal repertoire of the Yellow-thighed Brushfinch includes a heavy metallic 'tchuk' call. Pairs often exchange a twittering, tinkling greeting. The male's song is a series of high, dry notes that can be described as 'tee tididee dee wink wink' or similar phrases.

Breeding

The female constructs a bulky cup-shaped nest from plant material, which is well-hidden in coarse grasses, bamboo, or a thickly-foliaged tree, positioned 0.7-4.6 meters above the ground. She lays two eggs, white or pale blue with brown blotches, and incubates them for a period of 12–14 days.

Diet and Feeding

The Yellow-thighed Brushfinch is an omnivorous feeder, foraging at all levels from the treetops to the ground. Its diet includes insects, spiders, a variety of berries, and it has been known to extract nectar from flowers.

Conservation status

The species is currently listed as Least Concern by the IUCN, indicating that it does not face any immediate threat of extinction.