Sandy Beach Reptiles
Hawksbill Sea Turtle (Eretmochelys imbricata)
Download 178.26 Kb.
|
Hawksbill Sea Turtle (Eretmochelys imbricata)T 
exas Status Endangered U.S. Status Endangered, Listed 6/02/1970 Description The hawksbill sea turtle is a small to medium sized turtle with shell lengths up to 36 inches. They are known for their beautiful brown shell, mottled with dark and light spots and streaks, which was once commonly used to make tortoiseshell jewelry. They are named after its conspicuous beaked snout. Life History Hawksbill sea turtles are the most tropical of all sea turtles. Hawksbill turtles nest primarily at night, but there are reports of daytime nesting, usually on uninhabited beaches. Although sea turtles are subject to predation throughout their life cycle, predation is particularly high during the first two years of life. The eggs are eaten by ghost crabs, raccoons, skunks, opossums, mongooses, and dogs. Hatchlings are preyed upon by mammals, sea birds, crabs, and carnivorous fishes. Predation continues to be high until the turtles are big enough to avoid being swallowed. Sharks are a formidable predator throughout the life cycle of the hawksbill. This carnivorous turtle has a highly variable diet consisting mostly of invertebrates such as sponges, jellyfish, crustaceans, sea urchins, and mollusks. In captivity, adults reach sexual maturity between 3 and 5 years of age, although wild turtles may take much longer to reach maturity. They can live as long as 30 - 50 years. Adults mate off the nesting beaches every 2 to 3 years during the nesting period, generally April through November. Female hawksbill turtles nest alone or sometimes in small groups. As with other sea turtles, females return to lay their eggs on or near the same beach where they hatched. Scientists believe that sea turtles navigate by using their own innate global positioning system. Hatchlings are born with the ability to navigate using the earth's magnetic field. The females may nest several times during a season, laying as many as 200 soft, round white eggs per nest. The eggs incubate in the sand for 47 to 75 days. The incubation period is longer when the weather is cool. Hatchlings emerge from the nest mostly at night, race quickly to the surf and swim hurriedly toward the open ocean. Nesting occurs in numerous places in the tropics. In the Americas, these include the beaches of the Yucatán Peninsula, southern Cuba, Costa Rica, islands of the Caribbean such as Virgin Islands, Jamaica, Dominican Republic, Turks and Caicos, and Grenada, northeastern Brazil, and Pacific coasts of Mexico and Panama. Habitat
Hawksbill turtles live in clear offshore waters of mainland and island shelves. They are more common where coral reef formations are present. In fact, they rarely stray far from the shallows and coral reefs. They are less migratory than other marine turtles. Hawksbill turtles nest on sandy beaches, often in the proximity of coral reefs. On land, it has a distinctive gait (walking stride). They move their flippers in diagonally opposite pairs, whereas other marine turtles move their front flippers together…the same action they use when swimming. Distribution Hawksbill sea turtles are found primarily in warmer waters of the Atlantic, Pacific, and Indian Oceans from Japan to Australia and the British Isles to southern Brazil. They are also found in the southern waters of Florida, the Gulf of Mexico, and the Caribbean. In Texas, the hawksbill is found in the Gulf of Mexico and occasionally on the Texas coast. Other
The hawksbill's brightly colored, thick scutes covering the carapace (top of the shell) are the source of "tortoise-shell" which has been used for centuries to make jewelry. Handicrafts made of tortoise-shell appear in many ancient cultures, in places like China, Ceylon, India, Oceania, and Rome. With the CITES (Convention on International Trade in Endangered Species) restrictions, international trade in tortoise-shell has significantly decreased, but harvest of the turtle for its shell is still a threat to its survival in some areas of the world. Attempts at farming these turtles have been unsuccessful. The meat and eggs of the hawksbill have long been a source of food for people, although the meat is considered toxic in some areas due to the food items consumed. Human exploitation of the nesting grounds and pollution pose long term threats to its survival. In the past, hawksbill sea turtles were often killed in large shrimp trawl nets. Today, turtle excluder devices (TED's) pulled by shrimp boats help reduce mortality from net entanglement Directory: cms -> lib2 -> TX01001414 -> Centricity -> ModuleInstance -> 18755 ModuleInstance -> Abraham Lincoln called for 75,000 militiamen on April 15, 1861, he and just about everyone else in the North expected a swift war lasting about 90 days ModuleInstance -> What is a Tectonic Plate? 18755 -> - ModuleInstance -> Geography of the Ocean and the Structure of Planet Water 18755 -> Shorebirds vs. Seabirds & Bird Species ModuleInstance -> Accelerated Reader Test List Report Download 178.26 Kb. Share with your friends:
|