Giant Hummingbird Species

The Giant Hummingbird (Patagona gigas) is the largest species of hummingbird in the world. Native to South America, this impressive bird can reach lengths of up to 8.7 inches (22 cm) and weigh up to 0.8 ounces (23 grams). Despite its large size, the Giant Hummingbird remains an agile and graceful flyer capable of hovering and rapid acceleration much like its smaller relatives.

Physical Description
The most striking feature of the Giant Hummingbird is its size. As the largest member of the Trochilidae family, it dwarfs other hummingbird species. The bill alone can reach nearly 2 inches in length. The plumage is mostly green on the top with a bronze sheen, an iridescent gorget (throat patch), whitish underparts, and a deeply forked tail. The vibrant, shimmering colors are more pronounced in males. Females possess the same patterning but in more subdued tones. Like all hummingbirds, the wings are small relative to the body and beat at high frequencies to enable hovering flight.

Habitat and Range
The Giant Hummingbird occupies the western regions of South America along the Andes Mountains. Its range extends from Venezuela and Colombia down through Ecuador, Peru, and Bolivia. Within this region, it resides primarily in mountainous areas up to elevations of over 12,500 feet. It prefers high altitude scrub and forest edges near meadows and streams. The thin air of the higher altitudes poses no respiratory challenges for the Giant Hummingbird as it, like all members of its family, has evolved a uniquely efficient respiratory system to extract enough oxygen while hovering.

As an obligate nectarivore, the Giant Hummingbird fulfills all its nutritional needs by feeding on the nectar of flowers. Its long bill and tongue are perfectly adapted for extracting nectar. While feeding, the hummingbird inserts its bill into the flower where the tongue can lap up nectar. Unlike bees, the bill and tongue do not damage the flower during this process. therefore enabling a symbiotic relationship whereby the bird gains nourishment from the flower’s nectar while the flower benefits from pollination.

The Giant Hummingbird’s enormous size requires a proportionally immense intake of nectar. It feeds primarily on the nectar of large cup-shaped high mountain blooms adapted specifically for pollination by Giant Hummingbirds. Among these flowers are species in the genera Bomarea, Angelica, and Puya. When feeding on these flowers, the Giant Hummingbird hovers in front of the plant while lapping nectar from the base of the bloom. The curved bill matches the curvature of the nectaries. In this manner, the Giant Hummingbird can gain access to nectar that would be beyond the reach of a smaller species. In one feeding session, the Giant Hummingbird can consume up to twice its body weight in nectar.

Courtship and Reproduction
The breeding season for Giant Hummingbirds coincides with peak flowering in their mountain habitat. Courtship displays involve males ascending rapidly up to 130 feet in the air before swooping down past the female. Mating occurs while perched. Females build a small cup-shaped nest out of plant fibers, spider webs, and lichens on a low horizontal branch or tree fern. She lays two pea-sized white eggs. Incubation lasts roughly 16-19 days. Once hatched, the chicks remain in the nest for another 30 days as they are cared for and fed by the female.

Contrary to many of its diminutive relatives that make lengthy migrations, the Giant Hummingbird remains in residence throughout the year in its Andean range. This likely eliminated the need to evolve a hyperphagic period prior to migration during which it would consume more nectar to store fat. While Giant Hummingbirds do not migrate, individuals may make altitudinal movements up and down mountain slopes to take advantage of flowers coming into bloom at varying elevations through the seasons.

Adaptations for High Elevation Living
Life at high elevations poses numerous physiological challenges including scarce oxygen, wide temperature fluctuations, and low air pressure. Remarkably, hummingbirds possess adaptations enabling sustained activity in these conditions. The Giant Hummingbird’s large body mass helps counteract hypothermia in the cold. Its wings, though small, can generate sufficient lift even in thin air to hover and fly. But most importantly, the hummingbird’s metabolism has evolved to function optimally in oxygen-deprived environments.

When at rest, hummingbirds have an extremely slow metabolic rate and heart rate for such a small animal. This prevents consuming unnecessary energy between feeding bouts. During flight, however, its metabolic rate can increase to up to 50 times the resting rate, fueled by rapid breathing and heartbeat. This enables the sustained energy output necessary to power hovering wings.

But high elevation air contains roughly 40 percent less oxygen than at sea level. To compensate, the Giant Hummingbird’s trachea splits into two bronchi that each direct air to a separate lung rather than a shared one like in most birds. This anatomical adaptation allows more efficient oxygen extraction when flying in thin air. Additionally, hummingbirds have proportionally more capillaries surrounding each alveolus where oxygen is absorbed than other bird species. This maximizes diffusion of oxygen into the bloodstream. It also helps load oxygen onto hemoglobin because hummingbird blood has a higher concentration of red blood cells compared to mammals of similar size.

Role as Pollinator
The Giant Hummingbird’s most vital ecological role is as a pollinator for high Andean flowers. Due to its extensive range overlap with specialized flowering plants, the Giant Hummingbird likely co-evolved with many of its nectar sources. As it feeds, pollen sticks to the bird’s head and bill then rubs off on the next flower visited facilitating cross-pollination between separate plants.

Research indicates the Giant Hummingbird is the primary pollinator for at least 14 plant species. Since it feeds while hovering, the bird directly contacts the plant’s reproductive organs maximizing successful pollination. Experiments with fake flowers found the Giant Hummingbird preferred to visit larger blooms with wider openings, longer corolla tubes, and greater nectar volume. These oversized blooms match the bird’s specialized morphological adaptations like its long bill. Consequently, the survival of these plants and their hummingbird pollinators are closely interdependent. Without this and other specialized bird pollinators, many endemic plant species would likely decline or disappear from these delicate ecosystems.

Conservation Status and Threats
The dependence on localized high mountain habitats makes Giant Hummingbird populations especially vulnerable to climate change. Global warming has allowed tree line and scrub to encroach upslope, reducing open habitats. Precipitation and flowering patterns are shifting as well. If a significant seasonal mismatch arises between flowering and peak energy demands during reproduction, Giant Hummingbird numbers could rapidly decline. Connectivity between isolated mountaintop populations is also at risk if rising temperatures enable lower elevation biomes to expand and fracture vertical migratory corridors.

Habitat loss from human activities like logging, mining, agriculture, and grazing poses another threat. Additionally, tourism infrastructure development in the Andes introduces risks. Cable cars and ski lifts, for example, may enable spread of diseases and facilitate collisions. Unleashed pets could harass or prey on hummingbirds. Providing artificial nectar feeders also risks dependence although the birds seem to prefer legitimate flowers.

While still relatively abundant throughout its range, elevated threats to both the Giant Hummingbird and its high Andean habitat warrant increased focus on long-term research and monitoring. Maintaining connectivity between isolated populations will maximize genetic diversity and resilience. Careful planning of tourism expansion also needs to minimize encroachment into undisturbed open meadow areas vital as foraging grounds. With such measures, the scenic flashes of the Giant Hummingbird zooming across mountaintops will continue to brighten the heights of the Andes for generations to come.