The Cuban emerald (Chlorostilbon ricordii) is a species of hummingbird found only in Cuba and Isla de la Juventud. With its vibrant green plumage and long, slender bill, this tiny bird is considered one of the most beautiful hummingbirds in the world.
Description and Taxonomy
The Cuban emerald measures around 8-9 cm in length and weighs just 2-3 grams. The male has glittering emerald green upperparts and white underparts, with a straight black bill and pink legs. The female is similar but has slightly duller plumage, a greyer throat, and rounded tail feathers tipped with white.
The species was first described by French naturalist René Primevère Lesson in 1838, based on a specimen collected in Cuba. He named it Ornismya Ricordii after Dr. Alexander Ricord, an American physician living in Cuba who provided Lesson with many bird specimens.
In 1854 the Cuban emerald was moved to the genus Chlorostilbon, where it still resides today. Chlorostilbon is derived from the Greek words “chloros” for green and “stilbos” for shine. There are around 15 species in this genus, commonly called emerald hummingbirds due to their bright green plumage.
The Cuban emerald has no recognized subspecies. It is closely related to other Caribbean Chlorostilbon hummingbirds such as the Hispaniolan emerald and the Puerto Rican emerald.
Distribution and Habitat
As its name suggests, the Cuban emerald is endemic to the islands of Cuba and Isla de la Juventud in the Caribbean Sea. It can be found across the entire main island of Cuba, inhabiting coastal and inland forests, thickets, parks and gardens. Its preferred habitat is lowland moist forest and woodland edges.
On Isla de la Juventud (formerly called the Isle of Pines) the species is restricted to the western part of the island, where suitable forest habitat remains. It is thought that habitat loss, degradation and fragmentation across Cuba has resulted in some local declines in emerald hummingbird populations.
The Cuban emerald has adapted well to human modified landscapes such as plantations and gardens, provided there are flowers, small trees and scrub to provide food and nesting sites. It is classified as Least Concern on the IUCN Red List due to its relatively wide distribution and large population.
Diet and Feeding
Like all hummingbirds, the Cuban emerald feeds on nectar from flowers using its specialized long tongue. It uses its slender bill to probe blooms for nectar. Some favorite food plants include firecracker plant (Russelia equisetiformis), shrimp plant (Justicia brandegeana) and various Heliconia species.
The Cuban emerald is strongly territorial over preferred nectar-rich feeding sites. It aggressively chases away other hummingbirds that enter its territory, even larger species. It has also been observed stealing food from spiders’ webs.
In addition to nectar, Cuban emeralds eat small insects and spiders to obtain essential proteins and nutrients. They expertly hawk flying insects in midair or glean them from leaves and branches. Small arthropods are often plucked from spider webs invading the spider’s food source. A diverse habitat with nectar plants and insects is vital to support Cuban emerald populations.
Vocalizations
The male Cuban emerald produces simple vocalizations to advertise territory ownership and to court females. Its song is a high-pitched squeaky chip or cheep, barely audible to humans from a distance. Closer up, the wing feathers can be heard to produce a humming, buzzing and whirring sound in flight.
Reproduction and Life Cycle
The breeding season of the Cuban emerald extends from February to June. Males perform elaborate aerial displays to impress females, flying in u-shaped patterns while singing. Once paired, the female builds a tiny cup nest from plant down, fibers and spider webs, camouflaged on a tree branch.
She lays just two white eggs and incubates them alone for 15-18 days until hatching. The chicks are fed regurgitated nectar and insects by the female. They fledge at around 22 days old but remain dependent on the mother for several more weeks. Both parents cooperate to raise one brood per season.
Males are highly polygamous, mating with multiple females in a season. Females provide all parental care and do not remate if their first brood fails. The Cuban emerald is thought to live for around 5 years in the wild.
Conservation Status and Threats
The Cuban emerald has a relatively secure global population and is listed as Least Concern on the IUCN Red List of threatened species. Nevertheless, the species does face some conservation issues across its restricted island range:
– Habitat loss due to deforestation, urbanization and tourism development. Lowland coastal forests have been severely impacted.
– Degradation of habitat from invasive plant species, grazing livestock and pollution.
– Overcollection for the illegal pet trade due to the species’ beauty.
– Competition from introduced honeybees for nectar resources.
– Vulnerability to hurricanes and climate change impacts.
Various protected areas have been established across Cuba to safeguard key forest habitats. Setting aside natural forests and woodlots on agricultural land can help provide habitat connectivity. Promoting natural nectar plants in gardens and parks supports urban populations.
Limiting the trade in wild-caught birds helps counter illegal collection. Continued monitoring of populations and research is needed to conserve this unique and beautiful Cuban endemic hummingbird. With proper management, the vibrant Cuban emerald can continue to glisten over Cuba for years to come.