The Mountain Avocetbill Hummingbird (Opisthoprora montana) is a species of hummingbird found in the high elevation forests of the Andes mountains in South America. With its unusually long, curved bill that tapers to a fine, upturned tip, the avocetbill hummer is a specialist nectar feeder that has evolved to feed on flowers with equally long, curved floral tubes.
Physical Description
The mountain avocetbill ranges in length from 11-13 cm and weighs between 5-8 grams. The male has iridescent emerald green upperparts and white underparts, while the female is similar but has grayish underparts. Both sexes have a straight black bill that is extremely elongated and decurved. The bill length, from the tip to the base where the skull starts, is usually equal to the length of the rest of the body. The bill tapers gradually to a fine, upturned tip that allows the bird to probe deep into nectar-filled flowers.
The avocetbill hummer’s wings are fairly short and rounded compared to other hummingbird species. The male has a glittering purple crown and throat, while the female has white and gray head markings. The long tail is forked in the male and square-tipped in the female. Juvenile birds resemble adult females.
Distribution and Habitat
The mountain avocetbill is found in cloud forest and elfin forest habitats at elevations between 2500-4000 meters in the Andes of Venezuela, Colombia, Ecuador, Peru, and Bolivia. Its range is localized and fragmented across these countries.
The hummer inhabits cool, humid montane forests often shrouded in mist. It prefers areas with an abundance of flowers with long, curved floral tubes that match the specialized shape of its bill. Some of its favorite food plants include species from the families Bromeliaceae, Ericaceae, and Gesneriaceae. It also feeds at the flowers of epiphytic orchids and shrubs such as fuchsias. The avocetbill hummer is a high elevation specialist, with populations centered on specific mountain ranges.
Feeding Ecology
With its slender, curved bill that is perfectly adapted for probing into flowers with long, tubular corollas, the avocetbill hummer is a specialized nectar feeder. Its bill length exactly matches the corolla depth of its favorite food plants. Primary nectar sources include colorful mountain shrubs such as fuchsias, along with bromeliads, orchids, and other wildflowers with similarly elongated floral tubes.
The hummer hovers precisely in front of the flower and uses its specialized bill to probe deep inside the corolla, extracting nectar with fast lapping movements of its tongue. The bill’s fine tip is flexible enough to curve around stamens and styles to reach the base of the flower where the nectar pools. When feeding, the avocetbill hummer’s head may be completely hidden inside the long tubular flowers.
In addition to nectar, the hummer supplements its diet with small arthropods including insects and spiders. It gleans these animal prey items from foliage using its bill.
Reproduction
Mountain avocetbill hummingbirds breed between March and June. As part of courtship, the male performs aerial dive displays and song flights to impress females. Once paired, the female builds a small, cup-shaped nest out of plant down and spider webs, attached to a vertical twig or fern frond. She lays just two tiny white eggs.
The female incubates the eggs alone for about 16-19 days until they hatch. The chicks are fed regurgitated nectar and insects by the female. They fledge at approximately 20-23 days old. Not much else is known about the breeding habits of this elusive high elevation species. Their nests are difficult to locate within the dense, mossy forests they inhabit.
Conservation Status
The mountain avocetbill hummingbird has a very small, fragmented range and its population trend is decreasing. Habitat loss from deforestation of Andean cloud forests is the biggest threat this species faces. Climate change is also projected to shift and reduce the extent of high elevation flowering plant habitat in the coming decades. For these reasons, the avocetbill hummer is considered Near Threatened by the IUCN Red List. More research and monitoring of populations is needed to determine whether increased legal protections will be required in the future. Ecotourism may help provide an incentive to preserve remaining habitat for this unique hummingbird.
Conclusion
With its distinctive bill perfectly adapted to probe into long tubular Andean flowers, the mountain avocetbill hummingbird has carved out a specialized niche in high elevation cloud forests. While globally secure for now, increased protections may soon be needed for this range restricted species. The avocetbill hummer serves as an iconic example of unique biodiversity found in tropical mountain regions, and ecotourism and habitat conservation will ideally allow human communities to peacefully coexist with this unique pollinator.