The Black-breasted Puffleg (Eriocnemis nigrivestis) is a species of hummingbird found in Ecuador and Colombia. With its predominantly black and white plumage, distinct puffy white leg feathers, and long bill, the Black-breasted Puffleg is a striking and unique hummingbird. This species is endemic to a small region of South America and has adapted to survive in the cool, humid cloud forests of the Andes Mountains.
Introduction
The Black-breasted Puffleg is one of over 300 species of hummingbirds found in the Western Hemisphere. Hummingbirds are known for their diminutive size, jewel-toned iridescent plumage, incredible flying abilities, and complex courtship displays. The Black-breasted Puffleg exhibits many classic hummingbird traits, yet its stark black and white plumage and preference for high elevation cloud forests set it apart from most other hummingbirds. This species is listed as Near Threatened by the IUCN Red List due to its small and declining population. Protecting remaining habitat and studying the life history of the Black-breasted Puffleg are key to conserving this unique bird into the future.
Physical Description
The adult male Black-breasted Puffleg has predominately black plumage on its head, back, wings, and tail. The most striking white markings include a white breast band, white leg puffs, white tipped tail, and white streaks along the sides. The black bill is long, straight, and thin as is typical of hummingbirds that pollinate cloud forest flowers with long corollas. The female resembles the male, but has greyer plumage on the head and back along with a smaller breast band. The white leg puffs of both sexes are unique among hummingbirds and function to insulate the legs in cold temperatures. Juveniles exhibit dusky grey and brown plumage with smaller leg puffs until they molt into adult coloring at around one year of age. Standard measurements for the species are 7.5–8.5 cm in length and 4–5.2 g in weight.
Distribution and Habitat
The Black-breasted Puffleg occupies a narrow distribution from central Colombia to northern Ecuador. Its breeding habitat is confined to isolated patches of mountain cloud forest and elfin forest at elevations between 2400–3600 m. These moist forests experience cool, humid conditions year-round with frequent fog and mist. Tall trees dominate the landscape, many covered in epiphytes like mosses and orchids. Thick vegetation on the forest floor creates a dark understory. The puffleg may also forage in mountain shrublands and along forest edges. Its small range and specific habitat preferences make the species vulnerable to habitat loss.
Behavior and Diet
This hummingbird feeds through traplining, visiting a regular circuit of flower clusters each day. Nectar from cloud forest flowers makes up the majority of its diet. It prefers flowers with long, curved corollas like those of the genus Bomarea in the Alstroemeriaceae family. The puffleg’s long bill allows it to access the nectar of these specialized flowers. To supplement nectar, the puffleg feeds on small arthropods like flies, gnats, and spiders. Foraging occurs from lower levels up to the canopy for a variety of food sources.
The flight of the Black-breasted Puffleg is described as slow and fluttering, with wings beating nearly 60 times per second. This flight pattern allows maneuverability within dense forest vegetation. The puffleg has been observed bathing by sitting near the edge of water on a branch and dipping its belly into the water.
This species exhibits territorial behavior, with males defending feeding territories from intruders. Territorial fights involve aerial chases and physical attacks initiated by the territory holder. Nearly continuous high-pitched vocalizations are associated with antagonistic encounters. Soft ticking sounds are used in non-aggressive situations.
Life Cycle and Reproduction
The breeding season for the Black-breasted Puffleg extends from March to August during the rainy season. Courtship consists of aerial displays where the male flies in wide loops up to 100 m across, interspersed with hovering in place. If a female perches near his display area, the male may fly in fast horizontal loops above her while vocalizing.
Small territories are maintained by mated pairs, with the male defending against intrusions from other males. The female constructs a delicate cup nest out of plant down and spider webs on a vertical twig or fern frond. She incubates the two tiny white eggs for 15-19 days before they hatch. The chicks fledge at around 20-23 days old. The female cares for the young without assistance from the male.
Threats and Conservation
With its limited range and specific habitat needs, the Black-breasted Puffleg faces threats on several fronts. Habitat loss from deforestation and conversion to pastureland has reduced and fragmented its cloud forest ecosystem. Climate change models predict declines in cloud forest areas that could seriously impact the species in the future. Competition from more aggressive hummingbirds expanding their range uphill may also pose problems.
Predation by snakes and Accipiter hawks likely takes a toll on eggs, nestlings, and adults. Parasitism of nests by flies and wasps can decrease reproductive success. Potential pesticide exposure through chemical use in nearby agricultural fields is another concern.
The Black-breasted Puffleg is listed as Near Threatened by the IUCN Red List and protected under CITES Appendix II. Conservation plans aim to prevent further habitat loss in protected areas where the species occurs. Maintaining habitat connectivity through wildlife corridors allows populations to interact. Ecotourism initiatives feature the puffleg as a charismatic bird to generate interest in conservation. Further studies of population trends, reproduction, and feeding ecology are needed to fully inform efforts to protect this unique Andean hummingbird. With targeted conservation action, the one-of-a-kind Black-breasted Puffleg can continue glittering through its mountain forest habitat well into the future.