Olive ridley sea turtle in the context of "Sea turtles"

Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley. 5 of the seven species are listed as threatened with extinction globally on the IUCN Red List of Threatened Species, the remaining two are not considered to be threatened with extinction. One of which, the flatback turtle, is found only in the waters of Australia, Papua New Guinea, and Indonesia.

Sea turtles can be categorized as hard-shelled (cheloniid) or leathery-shelled (dermochelyid). The only dermochelyid species of sea turtle is the leatherback.

Sea turtle migration is the long-distance movement of sea turtles (superfamily Chelonioidea), comprising the swimming of adults to their breeding beaches, and also the offshore migration of hatchings. Sea turtle hatchings emerge from underground nests and crawl across the beach towards the sea. They then head offshore to the open sea. The feeding and nesting sites of adult sea turtles may be far apart, requiring some to migrate hundreds or even thousands of kilometres.

Several patterns of adult migration have been identified. Some green sea turtles shuttle between nesting sites and coastal foraging areas. The loggerhead sea turtle uses a series of foraging sites. Others such as the leatherback sea turtle and olive ridley sea turtle do not keep to one coastal foraging site, but forage in different areas in the open sea. Although the leatherbacks seem to forage randomly, drifting passively with the currents, they still return to specific sites to breed. The ability of adult sea turtles to travel to precise locations has led biologists to wonder about their navigational mechanisms. Some have suggested that turtles might use the Earth's magnetic field to fix their position. There is evidence for this ability in juvenile green sea turtles.

Kemp's ridley sea turtle (Lepidochelys kempii), also called commonly the Atlantic ridley sea turtle, Kemp's ridley turtle, and Kemp's ridley, is a species of turtle in the family Cheloniidae. L. kempii is the rarest species of sea turtle and is the world's most endangered species of sea turtle as well as the smallest. It is one of two living species in the genus Lepidochelys (the other one being L. olivacea, the olive ridley sea turtle). The species L. kempii primarily occupies habitat around the Gulf of Mexico, though its migrations into the Atlantic Ocean are being affected by rising temperatures. Rising sea temperatures expand this species range, leaving them vulnerable to cold-shocking events when weather changes. Kemp's ridley sea turtle is listed as endangered under the Endangered Species Act (ESA), and conservation efforts are attempting to rebuild population numbers. Human activity, including habitat destruction, climate change, and oil spills, threaten populations.

Cheloniidae is a family of typically large marine turtles that are characterised by their common traits such as having a flat streamlined wide and rounded shell and almost paddle-like flippers for their forelimbs. They are the only sea turtles to have stronger front limbs than back limbs. The six species that make up this family are the green sea turtle, loggerhead sea turtle, olive ridley sea turtle, hawksbill sea turtle, flatback sea turtle and the Kemp's ridley sea turtle.