| Ecological Descriptors
|Co, R, S
This turtle is named after their pointed beak-like bill, adapted for feeding on sponges. They have 4 costal scutes (shell plates), which do not touch the nuchal scute. A distinguishing feature are the 2 pairs of scales between the eyes (prefrontal scales) and overlapping scutes on the carapace (upper shell). Flippers have 2 claws(cf Green Turtle).
In Antigua adult females weigh between 40 and 60 kg (88 to 130 lbs), and shells range in length from about 75 to 95 cm (30 to 37 in). The shell has a characteristic "tortoishell" pattern, although this becomes less striking with age (young Green Turtles may appear similar). The rear marginal scutes are pointed, giving a "sawtooth" appearance to the rear half.
Hawksbills are important components of healthy coral reef ecosystems and are primarily spongivorous in the Caribbean (they are more omnivorous in the Indo-Pacific). Hawksbills support healthy reefs by controlling sponges which might otherwise out-compete slow-growing corals for space.
They are highly migratory and use a wide range of broadly separated localities and habitats during their lifetimes. Newly emerged hatchlings enter the sea and are carried by offshore currents into major gyre systems where they remain until reaching a carapace length of some 20 to 30 cm. At that point they move to a shallower, coastal (neritic) habitat that may comprise coral reefs or other hard bottom habitats, sea grass, algal beds, or mangrove bays and creeks or mud flats .
As they increase in size, immature Hawksbills typically inhabit a series of developmental habitats, with a tendency for larger turtles to inhabit deeper sites. While they undertake long migrations, some immature animals may settle into foraging habitats near their beaches of origin
In Antigua the breeding season for Hawkesbills runs from May to December, peaking in July to September. On Long Island their breeding activity has been closely monitored since 1987 by the Jumby Bay Hawksbill Project.
Hawksbills nest on sandy beaches and particulary like nesting under/ close to vegitation (e.g. Sea Grape shrubs, Coccoloba uvifera) . Female sea turtles to return to breed at their natal rookery, even though as juveniles they may have foraged at developmental habitats located hundreds or thousands of kilometers from the natal beach. Once sexually mature, they undertake breeding migrations between foraging grounds and breeding areas at intervals of several years.
Hawksbills do not reproduce every year. The time that elapses between successive nesting seasons, averages at ~3 years in Antigua. While most females return every two, three or four years, there are records of 7 or more years elapsing between an individual female’s consecutive nesting seasons.
Hawksbills generally lay four to six nests per season at two-week intervals, with clutch sizes of ~150 eggs. The incubation period is 55 to 70 days. All sea turtles exhibit temperature-dependent sex determination, with a greater proportion of females being produced at higher temperatures, whilst males are more common with lower incubation temperatures.
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