The Cozumel emerald (Chlorostilbon forficatus) is a species of hummingbird found only on the island of Cozumel off the coast of the Yucatan Peninsula in Mexico. With a total global population estimated at just 200-300 individuals, this iridescent green hummingbird is classified as critically endangered by the IUCN Red List.
Physical Description
The Cozumel emerald is a very small hummingbird, measuring only 7-8 cm in length and weighing 2-3 grams. As the name suggests, the male has brilliant emerald green upperparts and underparts, with a short black bill and white tips to the tail feathers. The female is less vividly colored, with greenish upperparts, white underparts with green flanks, a slightly longer bill, and less white in the tail.
Habitat and Behavior
This species is endemic to the island of Cozumel, inhabiting forest and woodland areas from sea level up to 750 m above sea level. The Cozumel emerald occupies a specialized niche, feeding on the nectar of helmet orchids and other small flowers such as Porterweed and Firecracker plants. It has a swift, direct flight pattern as it zips between flowers.
While foraging, the Cozumel emerald prefers areas of dense vegetation close to the ground and the edges of clearings. It aggressively defends small territories of optimal flowering plants against intrusions from other hummingbirds. During the non-breeding season, it may join mixed-species foraging flocks.
Reproduction
The Cozumel emerald breeds between March and June. The male performs aerial courtship displays, diving and rising in U-shaped patterns to impress prospective mates. Once paired, the female builds a tiny cup-shaped nest out of plant down, cobwebs and lichens on a branch or vine. She lays two pea-sized white eggs and incubates them alone for 15-18 days.
The chicks hatch blind, featherless but develop quickly, able to leave the nest about 18-23 days after hatching. The female cares for and feeds the chicks until they fledge. She may go on to raise 2-3 broods over the course of a breeding season.
Threats and Conservation
The major threats facing the endangered Cozumel emerald are habitat loss due to tourist development and logging of forests, as well as predation by invasive species such as cats and snakes. Its tiny global population and limited range on a single small island make it extremely vulnerable to extinction.
Protecting the species’ specialized coastal forest habitat is crucial. Part of the Cozumel emerald’s range falls within protected areas such as Cozumel Island Reserve and Punta Sur Ecological Reserve. Ongoing conservation efforts also include monitoring population trends, studying its ecology and raising awareness among local communities. A captive breeding program for the Cozumel emerald was started in 1994, but breeding the birds in captivity has proven very difficult.
More research is needed to estimate the current population size and model future population viability. Expanding protected areas, controlling invasive predators, restoring native vegetation and creating safe habitat corridors will be key to ensuring the long-term survival of this vivid island jewel. Without concerted conservation action, the Cozumel emerald faces an extremely high risk of disappearing forever.
Conclusion
The Cozumel emerald hummingbird is a critically endangered species found only on the small island of Cozumel in Mexico. With its brilliant green plumage and highly specialized feeding and habitat preferences, this species has become a symbol of the fragile diversity of island wildlife. Protecting its coastal forest home from tourism development and invasive species is crucial. While captive breeding has not been successful so far, wild population monitoring, expanded habitat protection and community engagement offer some hope. However, its tiny population size means the Cozumel emerald remains at high risk of extinction. Urgent action is needed to preserve both this unique hummingbird and the many other endemic species of Cozumel.