Lepidochelys kempii
Kemp's Ridley sea turtle

Kemp’s Ridleys (Lepidochelys kempii) can be found from Nova Scotia and Newfoundland to Bermuda. Nesting Ridleys are found mainly in the Gulf of Mexico. In migration, they follow two major routes: one heads north to the Mississippi coastline and the second extends southward to the shores of the Yucatan Peninsula at the Campeche Bank. (Ernst and Barbour, 1972; U.S. National Park Service, 2003; Wilkinson, 2003)

Lepidochelys kempii mainly stays near shallow coastal regions characterized by bays and lagoons. These turtles prefer waters that have sandy or muddy bottoms, but also may take to the open seas. At sea, this species has the ability to dive to great depths.

This species is rarely seen on shore, but it is not uncommon to see L. kempii floating in the water just offshore. Females come on shore to nest. (Ernst and Barbour, 1972)

Lepidochelys kempii is the smallest species of sea turtle, measuring from 55 to 75 cm in length. Average length is 65 cm. Individuals weigh between 30 and 50 kg. The head and limbs (flippers) are non-retractile. The shell is streamlined, making this turtle extremely hyrdrodynamic. The carapace is a gray-olive color, whereas the plastron is an off-white to light yellow color.

Lepidochelys kempii has four limbs; two foreflippers and two hindflippers. The foreflippers power the turtle through the water while the hindflippers are used to steer and stabilize the turtle in the water. One to two claws are present on each foreflipper.

Ridleys have an upper eyelid for eye protection. As turtles, they lack teeth, and the jaw has a broad-beak shape. The external features of males and females do not differ until they reach maturity. Males are characterized by longer, thicker tails, and may have larger curved foreflippers. (Ernst and Barbour, 1972)

Eggs are deposited on shore and incubate for an average of 55 days. Embryo development is temperature dependent. Lower nest temperatures tend to produce more males, whereas higher temperatures tend to produce more females.

Hatchlings uses a caruncle (temporary tooth) to break open the egg. After a hatchling escapes from the egg, it may take 3 to 7 days to crawl to the surface of the beach. Hatchlings emerge from the sand at night and immediately crawl towards the water. To locate the sea, hatchlings apparently orient themselves toward the greater light intensity reflected off the water. There may also be an internal magnetic compass that directs them to the water. After an individual hatchling enters the water, it goes into a “swim frenzy” for 24 to 48 hours. The hatchling swims into deeper water that protects it from predators.

The first year of life is spent away from shore. This year is dubbed the “lost year” because individuals in this age class are rarely seen near costal regions.

Lepidochelys kempii takes 11 to 35 years to reach maturity. (U.S. National Park Service, 2003; Wilkinson, 2003)

Mortality for L. kempii is very high around the time of hatching. For individuals reaching adulthood, lifespan generally ranges from 30 to 50 years. ()

This species is strongly adapted for swimming, spending nearly all of its life in the water. These turtles are migratory. Lepidochelys kempii spends most of its life in relative isolation. Social contact apparently occurs only during mating and nesting. The activity of these animals during days versus nights has not been well studied.

Home Range

Home ranges for individuals of this species have not been reported. ()

It is not known to what extent sea turtles communicate with one another. They make grunting noises which can be heard by other turtles, and apparently use these vocalizations to locate each other. Visual cues are probably important in identifying other members of their species, and some tactile communication undoubtedly occurs during mating. However, the bulk of communication in this species remains undescribed. (Scholastic and Inc., 1998; Scholastic and Inc., 2001)

Lepidochelys kempii feeds on floating crabs, mollusks, shrimp, jellyfish and some vegetation. The jaws of these turtles are shaped for crushing and grinding. (Ernst and Barbour, 1972)

Lepidochelys kempii is most vulnerable as a hatchling crawling from the nest to the shore. The slow-moving hatchlings make easy targets for herons, dogs, raccoons, and a variety of seabirds. The primary predatory threat to adults comes from sharks, especially the tiger sharks. Killer whales have also been known to consume sea turtles.

Human interference with nesting behavior may facilitate predation, and act as a barrier to this species. Lights around nesting areas confuses hatchlings about which way to crawl, sometimes causing them to crawl away from the water. Trash and noise can cause females to turn around from the nesting beach and back into the water, preventing deposition of eggs. The turtles are also hunted illegally to harvest meat. The shells can be made into combs and eyeglass frames. Eggs are also illegally collected because it is believed they have an aphrodisiac effect. (Ernst and Barbour, 1972)

Sea turtles have no significant economic role. Eggs and turtles were harvested in the past for reasons outlined under "Predation", but the harvesting of turtles or their eggs is now illegal. ()

There is no known direct economic importance for humans. ()

As a result of illegal harvesting, sea turtle meat may be eaten, and shells be made into combs or eyeglass frames. The eggs of L. kempii are believed to have an aphrodisiac effect. ()

Lepidochelys kempii is currently listed as endangered by the United States Fish and Wildlife Service and IUCN.