The Green-throated Mango (Anthracothorax viridigula) is a small hummingbird found in tropical regions of Central and South America. With its metallic green throat and belly, contrasting with black on the back and crown, the Green-throated Mango is one of the more striking hummingbird species.
Introduction
The Green-throated Mango is a mid-sized hummingbird, measuring around 8-10 cm in length and weighing 5-7 grams. As with all hummingbirds, the Green-throated Mango exhibits sexual dimorphism, with the male being more colorful and having a longer tail than the female. The male has an iridescent emerald green throat and breast, a violet-blue crown, and a mostly black back and tail. The female is less vibrantly colored, with a pale gray throat and breast, greener crown, and grayish back and tail with white tips.
The Green-throated Mango is found in tropical regions from southern Mexico through Central America and in northern and eastern South America. Its habitat includes forest edges, plantations, gardens, and savanna with flowering plants. The species is a year-round resident across most of its range. The Green-throated Mango is not considered threatened, with an estimated global population in the hundreds of thousands.
Physical Description
The most distinctive feature of the male Green-throated Mango, as its name suggests, is its metallic green throat and breast. The throat ranges from emerald to lime green, appearing almost luminescent in bright light. The breast is a slightly duller green fading to grayish on the belly. The back and top of the head are a deep purplish-black, while the face is violet-blue. The tail is primarily blackish with an emerald green base. The bill of the Green-throated Mango is straight and black. The female lacks the bright coloration of the male. Her throat and breast are pale gray, the back is dark gray, and the tail is gray with white tips. The female has a primarily dull green head. Juveniles of both sexes resemble adult females but have buffy scaling on the body feathers.
The Green-throated Mango averages 8-10 cm in length and weighs 5-7 g. The male’s tail is slightly forked and measures 5-6 cm, while the female’s tail is more rounded at 4-5 cm length. As with all hummingbirds, the Green-throated Mango has very small feet, used only for perching. The legs are covered in white downy feathers. The wings are long and narrow, optimal for sustained hovering and rapid flight. The wing length averages 5-6 cm.
Color Vision
Studies have shown that the Green-throated Mango, like most hummingbirds, possesses excellent color vision covering both human visible and ultraviolet wavelengths. Their visual spectrum allows them to differentiate minute variations in colors and patterns on flowers that are imperceptible to humans. This assists the birds in locating nectar sources and interacting with potential mates, which often have brightly colored plumage. The males in particular take advantage of their enhanced color perception in courtship displays to females.
Vocalizations
The vocalizations of the Green-throated Mango help the birds identify mates and defend their small territories. The most typical call is a rapid series of high-pitched squeaky chip notes. The call is given year-round by both sexes when approaching flowers or interacting with other individuals. The chip call grows faster and more insistent during aggressive encounters, especially among competing males. During the breeding season, males perform display dives in front of females, emitting a sharp clicking sound with their wing feathers throughout the dive.
Feeding Habits
Like all hummingbirds, the Green-throated Mango feeds primarily on nectar from flowers. It prefers flowers with sturdy bases that can support its weight. Some favored nectar sources include heliconias, ginger flowers, and flowering trees and shrubs like citrus, bottlebrush, and coral trees. The long, specially adapted tongue of the Green-throated Mango allows it to drink nectar while hovering at flowers. The bill is used like a straw to suck up nectar.
The Green-throated Mango supplements its diet with small insects including flies, beetles, butterflies, and spiders. The birds often hawk flying insects in midair. Insects provide essential amino acids not found in nectar. The Green-throated Mango locates insect prey visually, sometimes hanging onto a perch to glean bugs off vegetation.
Reproduction and Breeding
The breeding season of the Green-throated Mango varies across its range, tending to coincide with peak flower abundance. This ensures adequate nectar to feed the hungry young. In Central America breeding typically occurs between March and June, while Colombian populations breed June through August. During the breeding season, the male Green-throated Mango establishes and aggressively defends a small territory with plenty of flowers. He displays to visiting females by flying in dramatic vertical dives, reaching speeds over 100 km/hr while clicking his wings loudly. If a female perches within his territory, the male may continue the diving displays while flying tight loops around her.
Once paired, the female Green-throated Mango constructs the small cup nest on a thin horizontal branch or vine, often overhanging water. She builds the nest of soft plant down and spider webs, binding it to the substrate with silk. The outer nest is camouflaged with bits of bark, moss, and lichens. The female lays two tiny white eggs, about 0.5 cm long. She incubates the eggs alone for 15-19 days. The chicks hatch with eyes closed and almost no feathers. The female cares for and feeds the chicks through their three-week nesting period. She shelters them from rain and cold temperatures. The male plays no role in incubation or raising the young. Once they fledge, the female continues feeding the fledglings for a week or more as they learn to forage. The young reach sexual maturity and begin breeding in their first year.
Migration
Most populations of the Green-throated Mango remain resident across their breeding range year-round. Some seasonal elevational migration may occur, with the birds moving to lower tropical elevations during the winter dry season when flowers are scarcer in the highlands. However, even in coastal areas the Green-throated Mango can be found year-round.
The exception is the northernmost Mexican subspecies, A. v. calolaemus, which migrates south to Central America for the winter. These northern birds breed in scrub forest along Mexico’s Pacific coast. Their winter range stretches across Guatemala, El Salvador, Honduras, and Nicaragua. Banded birds from El Salvador have been recaptured over 1000 km north in Mexico the following breeding season. The Green-throated Mango’s small size allows it to undertake this lengthy migration and return with pinpoint accuracy to the same breeding sites annually.
Behavioral Ecology
The Green-throated Mango, like most hummingbirds, is a solitary and territorial species outside of the breeding season. Males are highly aggressive towards other males intruding in their flower-rich feeding territories, engaging in intense aerial fights and prolonged chasing. Territorial disputes are common at preferred nectar sources like stands of flowering heliconia. The resident male attempts to drive away any rival males approaching his territory by performing intimidating display dives. Actual physical contact is rare though the acrobatic chases may persist for minutes at a time until one bird retreats.
Females defend smaller feeding territories from each other as well. Both sexes are bold and curious, aggressively driving away much larger intruders including hawks, parrots, and toucans that approach their flowers. The Green-throated Mango advertises and protects its feeding territory by frequently emitting its conspicuous chip calls from perches within the area. It is also strongly territorial around its nest, vigorously dive-bombing any animal that strays too close.
When not breeding, the Green-throated Mango roams between a cluster of preferred feeding areas, following the blooming cycles of various plants. It perches quietly to rest between foraging bouts, conserving energy. The Green-throated Mango exhibits traplining behavior, repeatedly visiting productive flowers along circuitous routes. The birds remember locations of reliable nectar sources and return to them regularly. Territories may temporarily expand and overlap for access to abundant flowers.
Green-throated Mangos bathe frequently by perching near waterfalls or leaves where droplets collect. Bathing keeps their plumage in optimal condition. The Green-throated Mango undergoes an annual molt in the late summer, shedding old worn feathers for newer brighter ones over several weeks. It appears very ragged during this time until the molt is complete.
Ecosystem Roles
Through pollination, the Green-throated Mango contributes to maintaining the diversity and reproduction of tropical flowering plants. As it feeds on nectar, pollen grains stick to its bill and head feathers, traveling to the next blossom. Some plant species like heliconias rely almost exclusively on traplining hummingbirds for pollination. Plants visited by hummingbirds tend to have red or orange, tubular flowers suited to their long bills and hover-feeding. The Green-throated Mango’s habitat preferences perpetuate preferred nectar sources across its range.
While visiting blooms, the Green-throated Mango also picks up insects it transports to new areas. The birds play a role controlling populations of small arthropods like gnats, moths, and spiders that get stuck in their plumage. The Green-throated Mango itself provides an important prey item for small hawks and shrikes which heavily depend on catching hummingbirds. Nests may be raided by monkeys, snakes, and other predators. Overall the Green-throated Mango is a valuable component of neotropical ecosystems through its ecological relationships with insects, plants, and other animals.
Current Conservation Status
The Green-throated Mango has a large range and remains common across most of its habitat. Its global population is estimated at 500,000 to 5 million individuals and is not believed to be approaching the threshold for vulnerable status. While some local habitat degradation occurs, the species persists and even thrives in modified environments like gardens and parks. The Green-throated Mango is currently classified as Least Concern by the International Union for Conservation of Nature (IUCN) Red List, indicating it is not at immediate risk. Continued preservation of tropical forests and flowering plants will ensure thriving populations into the future. Providing nectar feeders and nest sites in developed areas may also contribute to ongoing conservation of the Green-throated Mango and other hummingbirds.
Fun Facts
– The Green-throated Mango flies as fast as 50-65 km/hr with its wings beating up to 70 times per second! This allows the tiny bird to sustain hovering and perform elaborate aerial displays.
– A Green-throated Mango’s heart rate can reach over 500 beats per minute during vigorous flight. This circulates oxygen efficiently to power sustained energetic activity.
– The iridescent throat feathers of male Green-throated Mangos do not contain pigment. Their vibrant color results from the refracting structure of the feathers. Shifts in viewing angle drastically alter the hue.
– Green-throated Mangos have extendable bifurcated tongues that fork into two tubes for nectar-feeding. Their tongues function like tiny straws to suck up liquid.
– During courtship displays, male Green-throated Mangos climb up to 40 meters in the air before diving down at breakneck speeds while clicking their wing feathers. This produces a metallic rattle audible from afar.
– Green-throated Mango chicks hatch with only a thin coat of gray down. Their eyes are sealed shut for the first week. The female feeds them with regurgitated nectar and insects.
– The Green-throated Mango’s tiny cup nest, decorated with lichens and spider silk, blends masterfully into the vegetation. The female is able to constructed a new nest in only 5-10 days.
– Traplining Green-throated Mangos exhibit spatial memory and flower constancy, preferentially returning to productive nectar sources they’ve previously visited along a route.
– The northern subspecies undertakes a lengthy annual migration up to 1000 km between its breeding and wintering grounds. Other populations remain resident year-round.
In Summary
With its striking vibrant plumage and energetic flight displays, the Green-throated Mango hummingbird is a beautiful tropical resident. As an important pollinator of native plants, predator of arthropods, and food source for other animals, this species fills an integral role in neotropical ecosystems. The Green-throated Mango exhibits remarkable adaptations for feeding, including morphological and behavioral specializations. This mid-sized hummingbird remains widespread and secure thanks to its ability to utilize both pristine and altered habitats. Continued efforts to preserve rainforests and provide nectar plants in developed areas will ensure the Green-throated Mango continues to thrive.