The Kemp’s Ridley Turtle’s scientific name is Lepidochelys kempii, but it’s also known as the Atlantic Ridley Sea Turtle. This species is the rarest and most endangered sea turtle on Earth. That may be due in part to this turtle’s unusual habit of nesting during the daylight hours.
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Characteristics and Appearance
Kemp’s Ridley Sea Turtles have dark colors as hatchlings, which helps them hide from predators. As they age, their plastron becomes a pale cream or yellow-green color. Their dorsal side and carapace become gray-green. That makes them blend into the deep water from above and the light of the surface from below.
The turtle’s triangular head ends in a distinctive beak. They have front flippers, each with one claw, and the back flippers can have one or two. Their bodies are streamlined and their carapaces almost round when viewed from above.
Weight and Length
Of all the different species of sea turtle, Kemp’s Ridley Sea Turtles are the smallest. Adults can be two to three feet long and weigh as much as 110 pounds. Hatchlings weigh half an ounce and are about as big as a soup spoon.
Physical Characteristics and Color
Adult Kemp’s Ridley Sea Turtles have a starkly contrasting color pattern. The top surface (carapace) is dark, and the underside (plastron) is very pale. They have five pairs of scutes that cover the carapace. Along the top center of the carapace, the scutes are raised and bony.
Unlike land turtles, these sea turtles cannot retract their legs or flippers back into their shells. Females use their hind flippers to dig into the sand and make nests for their eggs. The eggs are white and have a soft leathery shell.
The front of the head comes to a point that ends in a beak. The beak is a modified scale. It helps them break apart and eat their food. Unlike land turtles, sea turtles don’t continue to grow their beaks once they’re adults.
Lifespan and Reproduction
In the wild, a Kemp’s Ridley Sea Turtle’s lifespan is roughly 30 years. It can begin to reproduce at 13 years old. Every two to three years, these turtles return to land to lay their eggs in the sand. Each clutch is about 100 eggs. They hatch in about 55 days and make their way immediately back into the ocean.
These particular sea turtles nest during the daytime. Groups of females will come ashore together in what’s called an “arribada.” This behavior might help them avoid predators.
Egg-laying season is from May to June. They can lay more than one clutch per season, increasing the survival rate for the hatchlings. If a predator finds one nest, the other nest’s hatchlings might still survive.
Habitat
Kemp’s Ridley Sea Turtles spend most of their time in the Atlantic Ocean. The hatchlings hide in floating clumps of algae until they’re about three years old. The adults stay close to shore, where they can reach the sandy bottom and find food. Their mating cycles drive migration inland.
Where Do Kemp’s Ridley Sea Turtles live?
These sea turtles live in the warm waters of the Atlantic Ocean. They nest almost exclusively in Mexico along the East coast. Kemp’s Ridley Sea Turtles swim as far south as the Yucatán Peninsula and as far north as North Carolina. Most stay within the Gulf of Mexico.
Food and Diet
Kemp’s Ridley Sea Turtles are omnivores, meaning that they eat both plants and other animals. They are occasionally scavengers if they come across bycatch from fishing nets. The hatchlings survive on the organisms that live in the algae.
Adult turtles find their food on sand and mud sea bottoms along the continental shelf. They like to dine alone. These turtles only associate with each other during mating season. Otherwise, they’re solitary creatures.
These turtles have special jaws that allow them to crush the hard shells of their prey. They don’t have teeth, but they do have flat crushing surfaces in their mouths. A turtle’s beak can tear apart prey into bite-sized chunks.
What Do Kemp’s Ridley Sea Turtles Eat?
Their favorite food is crabs, specifically blue crabs and spider crabs. However, they will also consume jellies, mollusks, shrimp, and fish. They sometimes hunt near fishing boats, feeding on bycatch. Because of this, they’re often caught by fishing nets.
Threats and Predators
Kemp’s Ridley Sea Turtles are the most endangered species of sea turtle in the ocean. Their size and daylight nesting habits make them vulnerable to predators both as adults and as eggs. The biggest threat to their survival is human activity.
Human Threats
Habitat destruction dramatically reduces the number of Kemp’s Ridley Sea Turtles on the planet. Beach development can prevent these turtles from nesting in their traditional habitat. Invasive species like pigs that accompanied people to the coast (intentionally and unintentionally) eat turtle eggs.
Fishing boats hunt in the same areas where these turtles find their food. As a result, they get caught in fishing nets and drown. Some nets let turtles escape without releasing the fish. They also become trapped in trawls, dredges, and crab traps.
Oil spills are an additional threat to Kemp’s Ridley Sea Turtles. Thousands of adult and hundreds of thousands of juvenile sea turtles died after the Deepwater Horizon oil spill in 2010. Ingested oil can be toxic, and oil on their bodies affects their ability to swim properly.
Climate Change and Global Warming
A tenth of a degree in temperature change can mean the difference between a male or a female hatchling. As temperatures rise, it’s possible that more female turtles will hatch than males. That will alter the breeding dynamics of the species.
Higher temperatures may also lead to breeding out of season. The change is a problem because the species that the turtles rely on for food and shelter might not be available when they need them.
Predators
Humans have historically killed these turtles for food and leather. Poaching the adults and eggs add to the decline of these turtles.
Other predators include sharks and large sea mammals. They’re especially vulnerable as hatchlings. Shorebirds, pigs, raccoons, coyotes, and crabs feed on the tiny turtles as they make their way into the sea.
Other Threats
Sea turtles are reptiles. Like other reptiles, they don’t produce their own heat, instead relying on outside sources to keep them warm. When temperatures drop below 50 degrees, their mobility and heart rate slow down. They can get pneumonia, frostbite, and may even die.
Conservation Status
Kemp’s Ridley Sea Turtles are considered critically endangered by the ICUN (International Union for Conservation of Nature and Natural Resources). A famous film of one nesting event in the 1940s shows over 40,000 females coming ashore on one beach. Now, there are only around 22,000 of these turtles left in the entire world.
The turtles were showing signs of recovery until the 2010 oil spill. The future of these animals is still uncertain.
Fun Facts About Kemp’s Ridley Sea Turtles
- Male Kemp’s Ridley Sea Turtles don’t go back to shore after they hatch, spending their entire lives at sea.
- The temperature of the eggs is what determines if the hatchlings will be male or female. The warmer the nest, the more female turtles will hatch. Colder nests hatch more male turtles.
- Texas is the only state where Kemp’s Ridley Sea Turtles are native. South Padre Island is a significant nesting ground for these endangered animals.
- Richard M. Kemp was the first person to send a turtle specimen to Harvard. The origin of the name “Ridley” is unknown.
- Some males migrate to find females to mate with. Others stick to the same area, mating with females they encounter there.
- Even though several species of sea turtles nest in the Gulf of Mexico, the Kemp’s Ridley Sea Turtle is the only one that doesn’t nest anywhere else.
- Sea turtles have special glands near their eyes that help them eliminate extra salt from their saltwater habitat. That can give them the appearance of “crying.”
I am broadly interested in how human activities influence the ability of wildlife to persist in the modified environments that we create.
Specifically, my research investigates how the configuration and composition of landscapes influence the movement and population dynamics of forest birds. Both natural and human-derived fragmenting of habitat can influence where birds settle, how they access the resources they need to survive and reproduce, and these factors in turn affect population demographics. Most recently, I have been studying the ability of individuals to move through and utilize forested areas which have been modified through timber harvest as they seek out resources for the breeding and postfledging phases. As well I am working in collaboration with Parks Canada scientists to examine in the influence of high density moose populations on forest bird communities in Gros Morne National Park. Many of my projects are conducted in collaboration or consultation with representatives of industry and government agencies, seeking to improve the management and sustainability of natural resource extraction.
