The Tepui goldenthroat hummingbird (Thalurania ridgelyi) is a rare and critically endangered species endemic to the tepuis of southern Venezuela. Tepuis are table-top mountains found in the Guiana Highlands region of South America, characterized by sheer cliffs, unique plant and animal life, and isolated ecosystems. The fragile tepui ecosystems are under threat from climate change and human activity, putting the Tepui goldenthroat’s survival at risk.
Physical Characteristics
The Tepui goldenthroat is a small hummingbird, measuring just 10-11 centimeters in length. As its name suggests, the male has a brilliant metallic golden-colored throat which shimmers in the sunlight. The rest of the body is mostly dull green, with gray underparts. The long bill is slightly curved. Females lack the bright throat patch and are less vibrantly colored overall.
Habitat and Range
The Tepui goldenthroat is found only in the tepui regions of Bolívar state in southeastern Venezuela. Its habitat is restricted to the dwarf forests along the wet granite outcrops and cliffs of four isolated tepuis – Aprada, Amurí, Maverick, and the Eastern Quartzite Tepui region. It occurs at elevations between 1,800 and 3,000 meters. The combination of isolation and tiny range puts the total extent of its remaining habitat at less than 100 square kilometers.
Feeding Ecology
The Tepui goldenthroat feeds on nectar from the flowers of epiphytes and shrubs such as bromeliads and Ericaceae. It prefers flowers with a curved corolla to match its curved bill. Like other hummingbirds, it supplements its diet with small insects. It forages alone or in pairs, defending flower patches from intrusion by other hummingbirds. Due to its specialized habitat, it has access to fewer food sources than hummingbirds living at lower elevations.
Unique Adaptations
The Tepui goldenthroat exhibits unique adaptations that allow it to thrive in the cool, wet, windy conditions of the tepuis. Its small size and rapid metabolism allow it to generate heat quickly to withstand the cold. Its short wings provide great maneuverability for hovering in place while feeding on cliffside flowers. The dominance of dull green plumage provides camouflage against lichen and moss.
Reproduction
Relatively little is known about the breeding habits of the Tepui goldenthroat. They are solitary nesters. The tiny cup-shaped nest is constructed using plant fibers and spider silk, concealed in vegetation hanging from cliff faces. The female likely lays just two tiny white eggs. She alone incubates the eggs and cares for the young. Like other hummingbirds, the chicks hatch blind and nearly naked but develop quickly, leaving the nest in 2-3 weeks.
Population Status and Threats
The Tepui goldenthroat has an extremely small population estimated at only 250-999 mature individuals. Its population is severely fragmented, declining, and limited to just four isolated mountaintops. Habitat loss is the major threat facing this species. Climate change has caused increased drying of the tepuis, negatively impacting food sources. Human activities like mining and infrastructure construction destroy foraging and nesting habitat. Tourism brings risks from waste, trails, noise, and introduction of invasive plant species. Predation pressure from birds like falcons may also be elevated due to easier access from tourism activities.
Conservation Actions
The Tepui goldenthroat is classified as Critically Endangered by the IUCN Red List. Some of its habitat receives nominal protection due to its remote location. However, increased conservation action is urgently needed. Recommendations include formally protecting tepui habitats, controlling access, developing species management plans, and reducing human disturbance. Initiating studies focused on population monitoring, habitat conservation, and mitigating drying of the tepuis due to climate change is vital. Ecotourism focused on the hummingbirds could potentially aid conservation, if very carefully managed. Captive breeding has not yet been attempted but may be considered as a last resort. Without focused conservation action, this highly threatened species faces an extremely high risk of extinction in the coming decades.
Significance of the Species
The Tepui goldenthroat highlights the unique biodiversity found in Earth’s high elevation habitats. Tepuis harbor a wealth of endemic flora and fauna found nowhere else on the planet. Preserving these natural islands in the sky is crucial for protecting plant and animal species like the Tepui goldenthroat. Its striking beauty and perilous predicament can serve as a symbol to inspire conservation efforts. This delicate hummingbird clinging to existence in the misty heights of the tepuis represents nature’s fragility and humanity’s responsibility to steward such rare treasures before they are lost. By working urgently to preserve the Tepui goldenthroat and its unique habitat, we invest in the future of life on our planet.