The Green Hermit Hummingbird (Phaethornis guy) is one of the most fascinating and beautiful members of the Trochilidae family of hummingbirds. Despite their diminutive size, barely reaching 10 cm in length, these tiny birds lead remarkable lives and exhibit a number of intriguing behaviors and adaptations. In this article, we will explore the key aspects of the Green Hermit Hummingbird’s life history, ecology, and conservation status.
Range and Habitat
The Green Hermit Hummingbird is found exclusively in Central and South America, with a range extending from southern Mexico down through Panama, and south as far as Bolivia, southern Brazil and northern Argentina. Across this considerable range, the species inhabits tropical and subtropical forests, woodlands, plantations, and gardens. They tend to favor areas with plenty of flowering plants, thick vegetation, and shade. During the breeding season, they are territorial and the male will defend a feeding territory with suitable flower resources. The rest of the year they are more nomadic, tracking the flowering and fruiting of favored food plants.
Description and Taxonomy
The Green Hermit Hummingbird lives up to its verdant name, flashing brilliant emerald plumage in forest light gaps and along forest edges. The crown and upperparts of the male are a vivid green, while the underparts are grayish-white with green sides. The long bill is black, perfectly adapted for accessing nectar, and the eyes are chestnut brown. The female is similar with duller plumage overall. The species is medium-sized among hummingbirds, and there are several recognized subspecies across the range that vary slightly in size and color intensity.
Taxonomically, the Green Hermit Hummingbird belongs to the genus Phaethornis, commonly called hermit hummingbirds. This genus occurs only in the Americas and contains around 34 species. As their common name suggests, hermit hummingbirds tend to be solitary and territorial, inhabiting dense forest interiors. The Green Hermit was first scientifically described in 1788 by German naturalist Johann Friedrich Gmelin. Its species name guy refers to Dr. Guy Taché, a French naval surgeon and naturalist.
Feeding Behavior and Diet
Like all hummingbirds, the Green Hermit Hummingbird has unique adaptations for accessing floral nectar, the mainstay of its diet. Its long, specialized tongue can rapidly lap up nectar, curling back into the mouth between licks. The bill shape also allows the bird to deftly pick small arthropods from foliage to obtain protein and other nutrients.
The Green Hermit regularly visits a wide variety of tubular flowers to drink nectar, including heliconias, gingers, and other tropical plants. It prefers red-orange flowers adorned with heavy nectar loads. The species also hawks small insects in flight, gleans spiders from webs, and feeds on fruit pulp. Its unique craniofacial hinge allows the upper bill to flex upwards extensively, allowing it to pick apart fruit and obtain the soft interior.
Vocalizations
The vocal repertoire of the Green Hermit Hummingbird includes a diversity of chips, squeaks, and whistles used for communication. The male’s song is a repetition of sharp, squeaky notes, sounding like “pup-pup-pup”. This advertisement call alerts other males that a territory is occupied. Females may produce softer series of chips when interacting with their mate or offspring. Young chicks give piercing whistles from inside the nest to solicit food from their attending mother.
Aerobatic Flight and Metabolism
Green Hermits are accomplished flyers, capable of precision hovering in midair and sudden backward dodges while feeding. They can also fly quickly forward, attaining speeds over 50 km/hr despite weighing only 3-4 grams! This aerobatic flight is fueled by an incredibly high metabolism, with heart rates up to 1,260 beats per minute. Hummingbirds have among the highest mass-specific metabolic rates of any vertebrate. This intense metabolic engine allows them to power sustained hovering and endurance migration.
Breeding and Nesting
During the breeding season, male Green Hermits establish feeding territories centered around clusters of flowers. They perform elaborate aerial displays, arcing back and forth across their small territory while making their squeaky call. If a female enters, the male will chase her relentlessly until she perches, signaling her willingness to mate.
The female alone builds the small, cup-shaped nest out of soft plant fibers, moss, and lichens. It is camouflaged externally with epiphytes and suspended from a low drooping branch or tree fern frond. She lays just two tiny white eggs and incubates them for 15-19 days. The chicks hatch with closed eyes and almost no feathers. Both parents feed the chicks with regurgitated nectar and insects. After another 20-26 days, the nestlings finally fledge and start practicing flight. The female may raise 2-3 broods in a season if conditions allow.
Migration
Most northern and highland populations of Green Hermits are migratory, moving to lower, warmer elevations in winter. Their flight muscles allow them to fly hundreds of kilometers between breeding and wintering grounds. Banding studies have traced migrations between Mexico through Central America. Southbound travel begins as early as July, and northward migration back to the breeding grounds commences in March.
During migration, Green Hermits can pass across ecological barriers like ocean straits. One banded individual was recorded flying over 650 km of open ocean from the Yucatan Peninsula to Cuba – an astonishing feat for a bird weighing a few grams! The orientation mechanisms and navigation systems that guide their long-distance movements remain mysterious.
Conservation Status and Threats
The global population of Green Hermit Hummingbirds is estimated at 500,000 to 5 million individual birds. Partners in Flight categorizes the species as a species of Least Concern, meaning it is not currently vulnerable to extinction given its extensive range and large population. However, habitat loss across Central and South America does pose a localized threat in some regions.
Deforestation reduces flowering trees and expands open areas unsuitable for this forest-interior species. Selective logging also degrades the mature, humid forest this species relies on for nest sites and concealment from predators. Sustainable forestry initiatives, coupled with protected forest reserves and shade coffee or cacao offer conservation opportunities across the Green Hermit’s range. Protected areas like tropical forest national parks and reserves provide crucial safe havens for the species.
In Conclusion
While tiny, the beautiful Green Hermit Hummingbird exhibits an array of superb adaptations for capturing floral nectar and navigating dense tropical forests. Its hover-feeding, specialized tongue, and territorial displays offer fascinating glimpses into the life of specialized nectarivores. This species highlights the incredible diversity and complexity of hummingbird ecology across the New World. Safeguarding tracts of primary tropical forests and access to diverse nectar plants will be key to ensuring the future of the vibrant Green Hermit and its tropical forest kin. Through careful stewardship of these fragile ecosystems, these emerald gems can continue dazzling future generations with their aerial maneuvers.