The Hispaniolan emerald hummingbird (Chlorostilbon swainsonii) is a small hummingbird found only on the Caribbean island of Hispaniola. With its glittering emerald green plumage, the Hispaniolan emerald is considered one of the most beautiful hummingbirds in the world.
Physical Description
The Hispaniolan emerald measures about 3.5 inches (9 cm) long and weighs around 2-3 grams. The male has an iridescent emerald green crown, throat, back and tail. Its underside is grayish-white. The female is similar but lacks the iridescent throat patch and may show some bronze-green coloring on the crown. The long, slender bill is straight and black.
Habitat and Range
The Hispaniolan emerald is endemic to the island of Hispaniola in the Caribbean Sea. Hispaniola is home to two countries – the Dominican Republic and Haiti. The hummingbird can be found across diverse habitats on the island including mountain forests, coffee plantations, gardens and parks from sea level up to elevations of 7,200 feet. Its range is however restricted to only 5% of the island due to significant habitat loss. The global population is estimated at between 600-1700 mature individuals.
Feeding Habits
Like all hummingbirds, the Hispaniolan emerald feeds on nectar from flowers using its long extendable tongue. It favors flowers with red and orange blossoms that are tubular in shape. Some favorite nectar sources are tropical shrubs such as firecracker plant, shrimp plant, canna lily, hibiscus and poinciana. The hummingbird inserts its bill into the corolla of the flower to lap up the nectar while hovering in mid-air. It may also perch on a nearby branch while feeding.
In addition to nectar, the hummingbird feeds on small insects like gnats, flies and spiders. The protein from insects is an important part of its diet. Insects are captured during flight or gleaned off leaves and branches.
Unique Adaptations
The Hispaniolan emerald hummingbird has several unique anatomical and physiological adaptations that allow it to thrive on its Caribbean island home.
– Swift flight – Its small size, lightweight body and aerodynamic shape give the hummingbird exceptional agility in flight. It can fly forwards, backward and even upside down! The wings beat up to 70 times per second enabling the bird to hover and change direction instantly.
– Bills and tongues – The long, slender bills of hummingbirds are perfectly adapted for reaching nectar at the base of long, tubular flowers. Their tongues are tube-shaped with fringed tips that lap up nectar.
– High metabolism – A hummingbird’s metabolic rate is the highest of all warm-blooded animals. Their rapid heartbeat and breathing allow them to generate enough energy to power their busy wings during constant flight.
– Temperature regulation – Unlike other birds, hummingbirds are able to maintain a constant high body temperature (about 107°F) both at rest and while active. Adaptations like shivering allow them to keep warm in cool climates.
– Water balance – Hummingbirds have the ability to excrete excess water which allows them to cope with their high intake of nectar and dilute bird baths or rainwater.
Breeding and Nesting
The breeding season of the Hispaniolan emerald runs from March to June. The male performs aerial courtship displays, flying in loops and dives to impress watching females. After mating, the female builds a tiny cup-shaped nest out of plant down, spider webs and lichens on a low branch or fork. She lines the nest with soft plant fibers.
The female lays just two pea-sized white eggs. She incubates the eggs alone for 15-18 days. The chicks hatch out naked and helpless but grow quickly on a diet of regurgitated nectar and insects provided by the female. They fledge in about 20-26 days, gaining their full adult plumage after about a year. The Hispaniolan emerald faces threats from habitat loss and fragmentation, climate change, pollution and competition from invasive species. Conservation efforts focus on habitat protection, captive breeding and reducing pesticide use.
Species Profile
– Scientific Name: Chlorostilbon swainsonii
– Other Names: Hispaniolan emerald, Esmeralda de La Española
– Description: Tiny glittering emerald-green hummingbird endemic to Caribbean island of Hispaniola. Sexual dimorphism in plumage.
– Size: 7.5-9 cm long (3-3.5 inches); 2-3 grams weight
– Habitat: Tropical forests, plantations, parks and gardens from sea level to 7,200 ft elevation
– Range: Restricted to Hispaniola island (Dominican Republic and Haiti)
– Diet: Nectar, pollen, insects
– Lifespan: 3-5 years (typical)
– IUCN Red List Status: Endangered
In summary, the Hispaniolan emerald hummingbird is a diminutive and dazzling bird adapted to feed on nectar from tropical flowers. Endemic to just a small part of the Caribbean, this endangered species faces an uncertain future due to extensive habitat loss across its range. Protecting remaining fragments of its specialized highland forest habitat is crucial to ensuring the survival of this tiny emerald jewel in the forest. With dedicated conservation efforts, the Hispaniolan emerald can continue to glisten over its Caribbean island home.