Named for its exceptionally large head.
Description: Head is very large with heavy strong jaws. Carapace is bony without ridges and has large, non-overlapping, rough scutes (scales) present with 5 lateral scute. Carapace is heart shaped. Front flippers are short and thick with 2 claws, while the rear flippers can have 2 or 3 claws. Carapace is a reddish-brown with a yellowish-brown plastron. Hatchlings have a dark-brown carapace with flippers pale brown on margins.
Size: Typically 2.5 to 3.5 feet in carapace length (80-110 cm).
Weight: Adult weigh between 155 and 375 pounds (70 -0 170 kg).
Diet: Primarily carnivorous and feed mostly on shellfish that live on the bottom of the ocean. They eat horseshoe crabs, clams, mussels, and other invertebrates. Their powerful jaw muscles help them to easily crush the shellfish.
Habitat: Prefer to feed in coastal bays and estuaries, as well as in the shallow water along the continental shelves of the Atlantic, Pacific and Indian Oceans.
Nesting: Nest at intervals of 2 to 4 years. They lay 3 to 6 nests per season, approximately 12 to 14 days apart. Lays average of between 100 to 126 eggs in each nest. Eggs incubate for about 60 days.
Status: U.S. - Listed as Threatened (likely to become endangered, in danger of extinction, within the foreseeable future) under the U.S. Federal Endangered Species Act. International - Listed as Endangered (facing a very high risk of extinction in the wild in the near future) by the International Union for Conservation of Nature and Natural Resources.
Threats to Survival: The greatest threat is loss of nesting habitat due to coastal development, predation of nests, and human disturbances (such as coastal lighting and housing developments) that cause disorientations during the emergence of hatchlings. Other major threats include incidental capture in longline fishing, shrimp trawling and pollution. Incidental capture in fisheries is thought to have played a significant role in the recent population declines observed for the loggerhead.
Population Estimate*: 44,560 nesting females.
Named for the green color of the fat under its shell.
Description: They are easily distinguished from other sea turtles because they have a single pair of prefrontal scales (scales in front of its eyes), rather than two pairs as found on other sea turtles. Head is small and blunt with a serrated jaw. Carapace is bony without ridges and has large, non-overlapping, scutes (scales) present with only 4 lateral scutes. Body is nearly oval and is more depressed (flattened) compared to Pacific green turtles. All flippers have 1 visible claw. The carapace color varies from pale to very dark green and plain to very brilliant yellow, brown and green tones with radiating stripes. The plastron varies from white, dirty white or yellowish in the Atlantic populations to dark grey-bluish-green in the Pacific populations. Hatchlings are dark-brown or nearly black with a white underneath and white flipper margins.
For comparison, the Pacific green turtle (aka Black Sea Turtle) has a body that is strongly elevated or vaulted and looks less round in a frontal view than other green sea turtles. The color is where you see the biggest difference with Pacific greens having a dark grey to black carapace and the hatchlings are a dark-brown or black with narrow white border with white underneath.
Size: Adults are 3 to 4 feet in carapace length (83 - 114 cm). The green turtle is the largest of the Cheloniidae family. The largest green turtle ever found was 5 feet (152 cm) in length and 871 pounds (395 kg).
Weight: Adults weigh between 240 and 420 pounds (110 - 190 kg).
Diet: Changes significantly during its life. When less than 8 to 10 inches in length eat worms, young crustaceans, aquatic insects, grasses and algae. Once green turtles reach 8 to 10 inches in length, they mostly eat sea grass and algae, the only sea turtle that is strictly herbivorous as an adult. Their jaws are finely serrated which aids them in tearing vegetation.
Habitat: Mainly stay near the coastline and around islands and live in bays and protected shores, especially in areas with seagrass beds. Rarely are they observed in the open ocean.
Nesting: Green turtles nest at intervals of about every 2 years, with wide year-to-year fluctuations in numbers of nesting females. Nests between 3 to 5 times per season. Lays an average of 115 eggs in each nest, with the eggs incubating for about 60 days.
Range: Found in all temperate and tropical waters throughout the world.
Status: U.S. - Listed as Endangered (in danger of extinction within the foreseeable future) under the U.S. Federal Endangered Species Act. International - Listed as Endangered (facing a very high risk of extinction in the wild in the near future) by the International Union for Conservation of Nature and Natural Resources.
Threats to Survival: The greatest threat is from the commercial harvest for eggs and food. Other green turtle parts are used for leather and small turtles are sometimes stuffed for curios. Incidental catch in commercial shrimp trawling is an increasing source of mortality.
Population Estimate*: 88,520 nesting females
named for its unique shell which is composed of a layer of thin, tough, rubbery skin, strengthened by thousands of tiny bone plates that makes it look "leathery."
Description: Head has a deeply notched upper jaw with 2 cusps. The leatherback is the only sea turtle that lacks a hard shell. Its carapace is large, elongated and flexible with 7 distinct ridges running the length of the animal. Composed of a layer of thin, tough, rubbery skin, strengthened by thousands of tiny bone plates, the carapace does not have scales, except in hatchlings. All flippers are without claws. The carapace is dark grey or black with white or pale spots, while the plastron is whitish to black and marked by 5 ridges. Hatchlings have white blotches on carapace.
Size: 4 to 6 feet (130 - 183 cm). The largest leatherback ever recorded was almost 10 feet (305 cm) from the tip of its beak to the tip of its tail and weighed in at 2,019 pounds (916 kg).
Weight: 660 to 1,100 pounds (300 - 500 kg).
Diet: Leatherbacks have delicate, scissor-like jaws. Their jaws would be damaged by anything other than a diet of soft-bodied animals, so they feed almost exclusively on jellyfish. It is remarkable that this large, active animal can survive on a diet of jellyfish, which are composed mostly of water and appear to be a poor source of nutrients.
Habitat: Primarily found in the open ocean, as far north as Alaska and as far south as the southern tip of Africa, though recent satellite tracking research indicates that leatherbacks feed in areas just offshore. Known to be active in water below 40 degrees Fahrenheit, the only reptile known to remain active at such a low temperature.
Nesting: Nest at intervals of 2 to 3 years, though recent research has indicated they can nest every year. Nests between 4 to 7 times per season, with an average of 10 days between nestings. Lays an average of 80 fertilized eggs, the size of billiard balls, and 30 smaller, unfertilized eggs, in each nest. Eggs incubate for about 65 days. Unlike other species of sea turtles, leatherback females may change nesting beaches, though they tend to stay in the same region.
Range: Most widely distributed of all sea turtles. Found world wide with the largest north and south range of all the sea turtle species. With its streamlined body shape and the powerful front flippers, a leatherback can swim thousands of miles over open ocean and against fast currents.
Status: U.S. - Listed as Endangered (in danger of extinction within the foreseeable future) under the U.S. Federal Endangered Species Act. International - Listed as Critically Endangered (facing an extremely high risk of extinction in the wild in the immediate future) by the International Union for Conservation of Nature and Natural Resources.
Threats to Survival: Greatest threat to leatherback sea turtles is from incidental take in commercial fisheries and marine pollution (such as balloons and plastic bags floating in the water, which are mistaken for jellyfish).
Population Estimate*: 35,860 nesting females.