Blue-capped Puffleg Hummingbird Species

The Blue-capped Puffleg Hummingbird (Eriocnemis glaucopoides) is a species of hummingbird found in the Andes mountains of Ecuador and Colombia. With its bright blue cap and glittering turquoise throat, the male puffleg is one of the most striking of all hummingbirds. The species can be found in high elevation cloud forests and elfin forests between 3,000-4,500 m (9,800-14,800 ft). They are a high elevation specialist, inhabiting the tree-line ‘ecotone’ habitat between forest and paramo grasslands.

The blue-capped puffleg is a medium-sized hummingbird, measuring 10-12 cm (4-5 in) in length. The male has a brilliant sapphire blue cap on the head, with a contrasting white postocular spot behind the eye. The upperparts are bronze-green, while the underparts are glittering turquoise on the throat, fading to a greyish white on the belly. The tail is dark bronzy-purple with white outer tail feathers. The bill is black, straight and of medium length. Females lack the blue cap and are generally duller, with bronzy-green upperparts, buff underparts with grey undertail coverts and bronzy-green central tail feathers.

The blue-capped puffleg belongs to the hummingbird genus Eriocnemis, commonly known as the ‘pufflegs’. This Andean genus contains around 10 species, characterized by dense leg feathering that goes down to the feet, giving the appearance of ‘puff legs’. The blue-capped puffleg is most closely related to the Glowing puffleg of Costa Rica and Western Panama highlands. The two likely diverged when humid lowland forest expanded between populations in northern South America and Costa Rica during warmer interglacial periods. The blue-capped puffleg has two recognized subspecies: E.g. glaucopoides (nominate Ecuador and south Colombia), and E.g. hypopygia (north Colombia).

Habitat and Distribution
The blue-capped puffleg is endemic to the Andes mountains of Ecuador and Colombia. Its range extends from south Colombia (Nariño Department) to central Ecuador (Cotopaxi and Bolívar provinces). Across this range, it occurs between elevations of 3,000-4,500 m. It frequents elfin forest, tree-line ecotonal habitats, and areas of rich flowering shrubs within paramo grasslands. Its prime habitat is moist elfin forest with abundant epiphytes and bromeliads. Trees include Polylepis, Gynoxys, Buddleja, Escallonia, and tree ferns.

Like all hummingbirds, the blue-capped puffleg feeds on nectar taken from a variety of brightly colored, tubular flowers. Documented nectar sources include species in the genera Bomarea, Passiflora, Centropogon, Fuchsia, and Befaria; as well as the bromeliad Puya. The puffleg uses its specialized, slender bill to reach nectar at the base of long corollas. It also takes small arthropods, which provide essential proteins and minerals. Aerial foraging is performed over forest canopy and adjacent open habitats. The species exhibits trap-lining behavior, repeatedly visiting productive flowers along established routes.

The blue-capped puffleg, like most hummingbirds, is solitary and territorial. Males sing from exposed perches to advertise territory ownership and attract females. The primary song is a long series of accelerating chip notes, but various squeaks, squeals and whistles are also given. Displays include aerial flights and rapid hovering in front of perched females. Courtship feeding of females by males has been observed, with the male passing arthropods and nectar to the female as part of mating ritual.

The breeding season for this species peaks between February and August, coinciding with periods of maximal flower availability. The female constructs a small cup nest on a horizontal branch or in a tangle of vines, mosses and epiphytes. The nest is built of soft plant fibers and spider webs, and decorated externally with lichens for camouflage. The female incubates the two white eggs for 15-19 days, and cares for the chicks until fledging at 22-25 days old. She is fed by the male during incubation and brooding.

Threats and Conservation
The blue-capped puffleg currently has a population trend that is suspected to be decreasing, but it remains fairly common throughout its range. Potential threats include habitat loss due to deforestation, fire, mining and urban expansion. Climate change may also pose a long-term threat, by shifting humidity levels and altering food availability. However the species is described as Least Concern by the IUCN Red List, due to its relatively large range and stable numbers. Parts of its range occur in protected areas like Podocarpus National Park in Ecuador. Conservation priorities include habitat protection, monitoring populations, and more research on its reproductive ecology and feeding biology. With appropriate conservation measures in place, the striking blue-capped puffleg should continue to brighten its Andean cloud forests for the foreseeable future.