The White-tailed Emerald (Elvira chionura) is a species of hummingbird found in Costa Rica, Panama, and parts of Colombia and Ecuador. With its vibrant green plumage and long, forked white-tipped tail, the White-tailed Emerald is a striking and unmistakable hummingbird. This article will provide an overview of the White-tailed Emerald, including its physical description, habitat, diet, behavior, breeding, conservation status, and cultural significance.
The adult male White-tailed Emerald has brilliant emerald green upperparts and underparts, with a bright blue-violet throat patch, known as a gorget. The long bill is straight and black. As the name suggests, the most distinctive feature of this hummingbird is its long, deeply forked tail, with bold white outer tail feathers. The female lacks the vibrant throat patch and has slightly duller plumage, with white marking on the tips of the outer tail feathers. Juveniles resemble adult females. The White-tailed Emerald measures 7-9 cm in length and weighs around 5-7 grams.
Habitat and Distribution
The White-tailed Emerald is found in humid lowland and foothill forests, forest edges, plantations, and gardens from sea level up to 1500 m elevation. Its range extends from eastern Costa Rica through western Panama and into parts of western Colombia and northwestern Ecuador. This species has a fragmented distribution, with populations centered in key protected areas throughout its range. Prime habitat appears to be mature forest with plentiful flowers and a dense understory.
Like all hummingbirds, the White-tailed Emerald feeds mainly on nectar taken from a variety of colorful tropical flowers, including banana flowers, Heliconia, and various herbs, vines, shrubs, and trees. It uses its long, specialized tongue to lap up nectar while hovering in front of flowers. The White-tailed Emerald will also feed on small insects for essential proteins and nutrients. A territorial bird, it prefers to feed alone but may allow shorter feeding visits by other hummingbirds within its territory.
Behavior and Breeding
The White-tailed Emerald is somewhat slow and deliberate in its flight compared to other smaller hummingbirds. Both sexes are highly territorial, with males aggressively defending their feeding territories from other males through chasing and vocalizations. Courtship displays include aerial flights by males to impress females. Once paired, females alone build a small cup nest out of plant down and fibers on the upper branch of a tree, usually 5-10 meters off the ground. She lays two tiny white eggs. The female incubates the eggs for 15-16 days until they hatch. The chicks are fed regurgitated food by the female and leave the nest at about 20-23 days old.
The White-tailed Emerald is evaluated as Least Concern on the IUCN Red List of Threatened Species. However, some local declines have been noted, particularly in western Panama. Threats include habitat loss, fragmentation, and degradation. This bird’s requirements for mature, humid, tropical forest habitat with adequate flowering plants make it vulnerable in areas where these conditions are not met. Providing protection in key reserves and forested areas throughout its range is important for the continued survival of the White-tailed Emerald.
The White-tailed Emerald is sought after by birders for its stunning beauty and charismatic nature. It has been designated the national bird of Costa Rica, where it adorns the 25 colón coin. The genus name Elvira commemorates Elvira Mendez, wife of the Costa Rican ornithologist Jose C. Zeledon. The White-tailed Emerald represents the uniqueness and biodiversity of the hummingbirds found in Central America’s tropical forests. Its threatened status can make it a symbol of habitat loss and the importance of conservation in preserving these sensitive bird species.
With its bright plumage, long forked tail, and energetic flight, the White-tailed Emerald is a jewel of Central America’s hummingbirds. As development and deforestation continue to threaten its preferred mature forest habitat, protected reserves that preserve habitat connectivity will be key to ensuring the future survival of this species. Maintaining the integrity of tropical forests remains critical for the persistence of specialized birds like the White-tailed Emerald. The conservation of this beautiful bird can stand as a greater call for the sustainable stewardship of biodiversity across Central America’s ecosystems.