Loggerhead sea turtle

Lore & Background

The loggerhead sea turtle is the world's second largest extant turtle after the leatherback sea turtle. Adults have an approximate weight range of 80 to 200 kg, averaging around 135 kg, and a straight-line carapace length range of 70 to 95 cm. The maximum reported weight is 545 kg and the maximum (presumed total) length is 213 cm. The head and carapace (upper shell) range from a yellow-orange to a reddish brown, while the plastron (underside) is typically pale yellow. The turtle's neck and sides are brown on the tops and yellow on the sides and bottom. The shell is divided into carapace and plastron, with scutes. Sexual dimorphism is only apparent in adults: adult males have longer tails and claws, shorter plastrons, wider and less domed carapaces, and typically wider heads than females. Lachrymal glands behind each eye excrete excess salt, giving the false impression of crying. The skull has maxillae that meet in the mid-line of the palate, and the portion behind the eyes is large and bulbous due to jaw muscles.

Reader's Guide

The loggerhead sea turtle is found in the Atlantic, Pacific, and Indian Oceans, as well as the Mediterranean Sea. It spends most of its life in saltwater and estuarine habitats, with females briefly coming ashore to lay eggs. The loggerhead sea turtle has a low reproductive rate; females lay an average of four egg clutches and then become quiescent, producing no eggs for two to three years. The loggerhead reaches sexual maturity within 17–33 years and has a lifespan of 47–67 years. It is omnivorous, feeding mainly on bottom-dwelling invertebrates. Its large and powerful jaws serve as an effective tool for dismantling its prey. Young loggerheads are exploited by numerous predators; the eggs are especially vulnerable to terrestrial organisms. Once the turtles reach adulthood, their formidable size limits predation to large marine animals, such as large sharks. The loggerhead sea turtle is considered a vulnerable species by the International Union for Conservation of Nature. In total, nine distinct population segments are under the protection of the Endangered Species Act of 1973, with four population segments classified as 'threatened' and five classified as 'endangered'. Commercial international trade of loggerheads or derived products is prohibited by CITES Appendix I. Untended fishing gear is responsible for many loggerhead deaths. 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. Turtles may also suffocate if they are trapped in fishing trawls. Turtle excluder devices have been implemented in efforts to reduce mortality by providing an escape route for the turtles. Loss of suitable nesting beaches and the introduction of exotic predators have also taken a toll on loggerhead populations. Efforts to restore their numbers will require international cooperation, since the turtles roam vast areas of ocean and critical nesting beaches are scattered across several countries.

Did You Know?

• The loggerhead sea turtle is the world's second largest extant turtle after the leatherback sea turtle.
• The maximum reported weight of a loggerhead is 545 kg and the maximum length is 213 cm.
• Lachrymal glands behind each eye excrete excess salt, giving the false impression that the turtle is crying.
• The loggerhead sea turtle cannot retract its head or flippers into its shell.
• The English common name 'loggerhead' refers to the animal's large head.