The Inagua Woodstar (Nesophlox lyrura) is a small hummingbird endemic to the Bahamas. With an average body length of 2.5 inches and weight of 2-3 grams, it is one of the smallest hummingbird species in the world. Its name comes from its habitat being limited to the islands of Great Inagua and Little Inagua in the southern Bahamas.
Physical Description
The Inagua woodstar has a slender, elongated bill and a short tail. The male has a brilliant orange-red throat, breast and belly. The forehead and crown are green, while the back and wings are mostly brownish-gray. Females lack the bright red throat and breast, instead having white underparts with some gray streaking on the throat. Both sexes have white markings behind the eyes.
Habitat and Diet
As its name suggests, the Inagua woodstar is found predominantly in scrubby woodland habitats on the Inagua islands. It occurs in semi-arid areas with scattered flowering plants and shrubs. Key plant species it depends on for nectar include Caribbean pine (Pinus caribea), Brazilian pepper (Schinus terebinthifolius), and various Heliconia species.
The Inagua woodstar’s small size allows it to hover and probe deep inside tubular flowers for nectar. It uses its extendable tongue to lap up nectar while hovering. This species also occasionally eats small insects for protein.
Unique Adaptations
The Inagua woodstar is the only hummingbird endemic to the Bahamas. Several unique adaptations allow it to survive on these hot, arid islands:
– Small body size reduces energy and water needs. The woodstar has one of the highest metabolic rates of any vertebrate relative to its size.
– Excellent flight capabilities, with wing-beat rates around 70 times per second. This allows efficient hovering at flowers even in windy conditions.
– Ability to enter torpor, a hibernation-like state, at night to conserve energy.
– Curved bill and specialized tongue allows it to access nectar from specialized flowers.
– Highly territorial behavior reduces competition for limited resources.
Reproduction and Lifespan
The Inagua woodstar breeding season coincides with peak flowering of its food plants, typically May to July. Females build a delicate cup nest out of plant fibers, spider webs, and lichen. The nest is only about 1 inch wide and usually placed in a tree fork or shrub up to 16 feet above ground.
Females lay 1-3 tiny white eggs. After a 14-16 day incubation, the chicks hatch. The altricial young are fed regurgitated food by the female and fledge in about 18-23 days. The Inagua woodstar has an average lifespan of 3-5 years.
Conservation Status and Threats
The Inagua woodstar has a very small global population estimated at only 1,000-2,500 mature individuals. Its total range is less than 500 square km. For these reasons, the IUCN Red List categorizes this species as Endangered.
Major threats include habitat degradation from invasive plant species, nest predation by rats and cats, and destruction of nesting trees. Climate change may also increase drought stress. Fortunately, its limited habitat is entirely within the Inagua National Park, providing protected habitat. Conservation efforts focus on controlling invasive plants, managing visitor access to sensitive areas, and restoring native vegetation.
Fun Facts
– The Inagua woodstar’s tiny nests, only about 1 inch wide, are the smallest nests of any bird relative to body size.
– At up to 80 wing flaps per second, the woodstar has one of the highest known wingbeat frequencies of any bird.
– Male and female Inagua woodstars look so different that they were originally thought to be separate species.
– Special feather adaptations, including a rounded tail and stiffened shafts, allow the woodstar to hover efficiently despite strong winds.
– This species prefers to forage at Congregation Flowers, where many individual flowers on a branch allow territorial birds to chase others away.
In summary, the endemic Inagua woodstar is a unique and critically endangered hummingbird adapted to survive in a challenging island environment. Protecting its limited Bahamian scrub habitat will be crucial for the longevity of this species. Despite its small size, the woodstar serves as an important pollinator for flowers on which it depends for food. Continued conservation efforts can help ensure this colorful and acrobatic bird continues to brighten its Caribbean home.