Black-thighed Puffleg

Scientific name: Eriocnemis derbyi

The Black-thighed Puffleg is a high-Andean hummingbird found from the Central Andes of Colombia south to northwestern Ecuador, where it favors bushy pastures, shrubby ravines, and humid forest edges near treeline. The number of mature individuals is unknown, its population trend is considered Stable (though habitat loss is a concern), and it is currently assessed as Least Concern.

At a Glance

• Family: Trochilidae (hummingbirds)

• Clade: Lesbiini – Coquettes

• Genus: Eriocnemis — Andean pufflegs with dense feather “puffs” around the legs

• Range: Central Andes of Colombia (Tolima and surrounding departments) south to Imbabura Province in northwestern Ecuador

• Habitat: Borders of humid montane forest, bushy pastures, low scrub near timberline, shrubby ravines, and second growth in somewhat open high-Andean landscapes

• Elevation: About 2,500–3,600 m, most common above 2,900 m

• Length: Around 10 cm (about 3.9 in)

• Weight: Approximately 4–5 g

• Number of mature individuals: Unknown

• Population trend: Stable

• Status: Least Concern (IUCN)

Name Origin
The genus name Eriocnemis comes from Greek roots meaning “wool” and “leg,” referring to the fluffy feather “puffs” around the legs that define the pufflegs. The species name derbyi honors Edward Smith-Stanley, the 13th Earl of Derby, a noted British naturalist and collector. The English name “Black-thighed Puffleg” points to the species’ distinctive black leg puffs, which contrast with the otherwise bright green plumage.

Subspecies & Distribution
Black-thighed Puffleg is monotypic, with no recognized subspecies.

It is found in the Central Andes of Colombia from Tolima Department southward to Imbabura Province in northwestern Ecuador. Across this narrow but high-elevation range it inhabits bushy pastures, low scrub at the timberline, shrubby ravines, second growth, and the edges of humid montane forest, favoring somewhat open, patchy vegetation near treeline.

Ledged
Green Resident

Species Overview
The Black-thighed Puffleg is a characteristic hummingbird of upper montane and subalpine habitats in the Central Andes. Its combination of shining green plumage and dark leg puffs makes it stand out among other high-Andean hummers. It often occurs where forest gives way to bushy pastures, low scrub, and second growth, and it readily uses man-made habitats such as pastures and gardens near the upper forest edge. Although it has a relatively small geographic range, its ability to occupy a mix of natural and modified habitats supports its current Least Concern status.

Male Description
Adult males are mostly shining golden-green overall, sometimes with darker, almost blackish highlights in certain lights. The upper and undertail coverts are a glittering malachite green, adding extra brilliance toward the rear of the body. Their leg puffs are dense and black, forming the “black-thighed” look that names the species, and the tail is forked and black. The bill is straight and blackish, and the overall impression is of a compact, bright green hummingbird with dark leg “boots” and a contrasting dark tail.

Female Description
Females are similar in structure but paler and more patterned below. They have green upperparts, but the underparts are white with green spots, giving a speckled or scaled look. Their leg puffs are a mix of black and grayish white rather than entirely black, and they show a bluish tinge on the forehead. Juveniles resemble females, sharing the spotted underparts and mixed leg puffs before adult colors fully develop.

Habitat & Behavior
Black-thighed Pufflegs inhabit bushy pastures, the borders of humid montane forest, low scrub near timberline, shrubby ravines, and high-elevation second growth in the Central Andes. They prefer somewhat open landscapes with scattered shrubs and low-growing flowering plants rather than dense closed forest. The species makes seasonal elevational movements, shifting up and down the mountains with flowering conditions.

They feed mainly on nectar from low-growing plants such as Fuchsia and certain palms, visiting flowers close to the ground and in shrubby patches. Their diet also includes small insects, which they catch by hawking—flying out from a perch to snatch insects in mid-air. Their vocalization is a short, buzzy trill “tzzrr,” repeated at irregular intervals from perches or while hovering, and it is quite different from the sounds of other puffleg species.

Population
The total number of mature individuals is not known, but the species is considered uncommon to locally common within suitable high-elevation habitats in Colombia and Ecuador. It has a moderately small range and is affected by ongoing habitat loss and modification, especially in montane forest and scrub zones. Nevertheless, its use of pastures, gardens, and other man-made habitats near forest edges contributes to a relatively stable population trend overall.

Conservation
Black-thighed Puffleg is currently assessed as Least Concern, but its limited range and dependence on high-Andean habitats mean it is sensitive to continued habitat changes. Deforestation, conversion of montane forest to pasture and agriculture, and changes in land use near timberline can reduce the bushy pastures, scrub, and forest edges it relies on. Conservation priorities include protecting remaining montane forest and subalpine scrub in the Central Andes, maintaining a mosaic of shrublands and second growth, and monitoring populations to detect any future declines. Its willingness to use pastures and gardens offers some resilience, but intact and semi-natural high-Andean landscapes remain important.

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Related species in the Eriocnemis genus (11 species total):

Please note: The content provided in this article reflects Anthony’s personal experience and photographic approach. Results can vary depending on light, weather, location, equipment, subject behavior, and field conditions.