Hawksbill
Status
Indian Wildlife (Protection) Act: Schedule I
IUCN Red list: Critically Endangered
Description
One of the smaller sea turtle species, the hawksbill turtle gets its name from its narrow, elongated head which tapers sharply with a V-shaped lower jaw. This gives the reptile a bird-like appearance. Hatchlings have a heart-shaped carapace which becomes elongated as the turtle matures. The carapace is orange, brown or yellow in colouration.
Adult hawksbills measure about 76-91 cm in length and weigh around 40-60 kg. Track marks are about 70 – 85 cm wide, are shallow and have asymmetrical (alternating) oblique marks that are made by forelimbs. Tail marks maybe present or absent. The track marks are very similar to those made by olive ridleys, which makes it very difficult to distinguish between the two. However, the two species nest on very different kinds of beaches.
Biology
Hawksbills are solitary nesters, they nest at intervals of 2-3 years, about 2 to 4 times per season. The female lays an average of 160 eggs in each nest (generally under vegetation) that take about 60 days to incubate. The hawksbill’s narrow head and jaws shaped like a beak permit foraging in crevices in coral reefs. They feed on sponges, anemones, squid and shrimp.
Habitat & Distribution
Hawksbills utilise both low- and high-energy nesting beaches in the tropical oceans of the world. They usually nest on small pocket beaches and, because of their small body size and great agility, can traverse fringing reefs that limit access to other species. They exhibit a wide tolerance for nesting substrate type.
The species is found throughout the central Atlantic and Indo-Pacific regions. It is the most tropical of all sea turtles. Hawksbills are known to inhabit different habitats at different stages in their development. Post-hatchling hawksbills occupy the pelagic environment, taking shelter in weed lines that accumulate at convergence points. Hawksbills re-enter coastal waters when they reach approximately 20-25 cm in length. As adults, they may occupy narrow beaches on islands or mainland shores, with reefs obstructing offshore approach. Coral reefs are widely recognised as the resident foraging habitat of juveniles, sub adults and adults.
In India, hawksbills are found in the Lakshadweep islands, Andaman islands, and few beaches in the Nicobar islands such as Indira Point at the southern tip of Great Nicobar (here turtles often have to crawl over reefs and rocks to reach the nesting beach).
Threats
Hawksbill turtles have been exploited over the centuries for their scutes, known as tortoiseshell, which is perhaps the biggest threat to hawksbill turtles around the world. In some countries the shell is still used to make hair ornaments, jewelry, and other decorative items.