Description: Named for their huge heads and powerful jaws, loggerhead turtles are the largest hard-shelled sea turtles alive today. They have a heart-shaped carapace, which is often covered with commensal organisms such as barnacles and algae. Generally, the carapace is a reddish-brown hue with olive tones; there are five pairs of pleural scutes, the first pair touching the cervical (neck) scute. The plastron is cream to yellow, and has two longitudinal ridges that disappear with age. The skin is dull to reddish brown dorsally and medium to pale yellow around the edges and ventrally. The skin may have some orange coloration as well. The skin of males is more brown and the head more yellow than those of females. Males also have wider carapaces and a long curved claw on each forelimb. Loggerhead sea turtle hatchlings tend to be dark brown to reddish brown on the carapace and cream to reddish brown or dark brown on the plastron. The average adult Caretta caretta in the Mediterranean Sea is smaller than the average adult in the Atlantic Ocean. Loggerhead sea turtles differ from other sea turtles in having relatively large heads and reddish coloration. Additionally, Ridley's sea turtles (Lepidochelys) have four inframarginal scutes on the bridge. Green sea turtles (Chelonia mydas) and hawksbill sea turtles (Eretmochelys imbricata) have only four pairs of pleural scutes on the carapace; the first pleurals do not touch the cervical scute.
Habitat: Preferred habitat of Caretta caretta individuals changes throughout the life cycle. Adult females go ashore to lay eggs and seem to prefer steeply sloped, high energy beaches. When hatchlings emerge from the nest, they head for the ocean. Young juveniles are typically found among drifting Sargassum mats in warm ocean currents. Older juveniles and adults are most often found in coastal waters and tend to prefer a rocky or muddy substrate over a sandy one. They may also be found near coral reefs and venturing into salt marshes, brackish lagoons, and the mouths of rivers.
Range:Caretta caretta is found in nearly all the world's temperate and tropical oceans: the Atlantic Ocean from Newfoundland to Argentina, the Indian Ocean from southern Africa to the Arabian Gulf to western Australia, the Mediterranean Sea, and the Pacific Ocean from Alaska to Chile and Australia to Japan. During winter months loggerhead sea turtles migrate to tropical and subtropical waters.
Diet: Eats various marine invertebrates (crustaceans, mollusks, sponges, cnidaria, echinoderms, etc.), few plants; also fish (carrion or slow-moving species). Horseshoe crabs are preferred prey in Chesapeake Bay. Spider crabs and rock crabs were important prey at Long Island, New York. Adults forage primarily on the bottom, also take jellyfish from surface. Young feed on prey (e.g., gastropods, fragments of crustaceans and sargassum) concentrated at the surface.
Reproduction: In the southeastern U.S., mating occurs late March-early June. Lays 1-9 clutches (mostly 2-6) of about 45-200 eggs (average 120) at intervals of about 2 weeks, mostly every 2-3 years. Nests mainly at night, often at high tide. In the U.S., nests late April-early September, peak in June. Eggs hatch in about 7-11 weeks (generally 8-9 weeks in the southeastern U.S.). Egg mortality may result from predation, beach erosion, invasion of clutches by plant roots, crushing by off-road vehicles, or flooding by sea water overwash or excessive rainfall. Sex of hatchlings is affected by incubation temperature, with warmer temperatures resulting in a preponderance of females and cooler temperatures producing mainly or only males. Hatchlings emerge from nest a few days after hatching, typically during darkness. Sex ratio of hatchlings and immatures in Atlantic coastal waters of U.S. is strongly biased toward females. Females are sexually mature at an average age of about 15-30 years in the southeastern U.S.. Females are reproductively active over a period of about 30 years. Nesting density reaches nearly 450 nests/km in some areas of Florida
Status: Caretta caretta, like all sea turtle species, is in decline. The greatest causes of decline world-wide is probably incidental capture in fishing gear such as long lines, gill nets, shrimp trawls, and direct exploitation of adult turtles and eggs for human food. Though in sharp decline in many parts of its range, and locally along North American coasts, loggerhead sea turtles are currently the most common and least-threatened marine turtle in North American waters. They are listed as threatened under the U.S. Endangered Species Act.
Other important causes of decline include beachfront development, human disturbance of nesting females, pesticides, petroleum products (oil spills), and other ocean pollutants, human-influenced increases in nest predators such as raccoons, collisions with watercraft, and offshore and channel dredging. Artificial lighting near beaches can confuse emerging hatchlings, causing them to move away from the ocean and into hazardous urban areas. If predictions about global warming are realized, increased storms and rising sea levels could damage or destroy nesting areas and nests, and temperature changes could skew sex ratios.
Disclaimer: ITIS taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. However, it is not a legal authority for statutory or regulatory purposes. While every effort has been made to provide the most reliable and up-to-date information available, ultimate legal requirements with respect to species are contained in provisions of treaties to which the United States is a party, wildlife statutes, regulations, and any applicable notices that have been published in the Federal Register. For further information on U.S. legal requirements with respect to protected taxa, please contact the U.S. Fish and Wildlife Service.
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