How Are Babies Made?
Females reach sexual maturity between the ages of seven and 15. They breed annually and nest an average of one to four times in a season at intervals of 10 to 28 days. Nesting occurs from May to July, when the turtles appear off the coasts of Mexico (see Behavior, below). After gathering offshore, females swarm to the beach during daylight hours to lay a clutch of approximately 100 eggs in a sandy nest they scoop with their flippers. The eggs incubate for 50-60 days. After incubation, hatchlings emerge weighing about half an ounce (14 grams) and measuring about 1.5 inches (3.8 centimeters) long. This is an extremely dangerous time for young turtles, a favorite food of shorebirds.
What Do They Do?
There’s a Spanish word, arribada, meaning “arrival,” that describes the amazing sight of Kemp’s ridley nesting behavior. Kemp's ridleys nest in a synchronized display that begins when large groups of females gather off a particular nesting beach near Rancho Nuevo, Mexico, during nesting season. No one knows what triggers an arribada, but all at once wave upon wave of Kemp’s ridley females come ashore together to nest. Scientists don’t know for sure, but they theorize that offshore winds, lunar cycles, or the release of pheromones by females may provide the cue for the turtles’ mass arrive. No one disagrees that a Kemp’s ridley arribada is an awe-inspiring event in the natural world. It’s a behavior that’s shared only by the olive ridley sea turtle, also a member of the genus Lepidochelys.
How Concerned Should We Be?
The International Union for Conservation of Nature (IUCN) has a “Red List” of species in danger globally and listed the Kemp’s ridley turtle as “critically endangered.” The Convention on International Trade in Endangered Species (CITES) prohibits any trade in turtles, their shells, their eggs, or any other body part. The most endangered of all sea turtles, Kemp’s ridley’s decline is primarily due to human activities, including the direct harvest of turtle eggs and adult turtles, and the incidental capture of thousands of turtles in the nets of shrimp trawlers and the gill nets, dredges, longlines and pots of other commercial fishing operations in the Gulf of Mexico and Atlantic. The decline of the Kemp’s ridley has been steep and dramatic, in part because 95 percent of the world’s turtles nest on one small area in Mexico.
What's Being Done?
The Convention on International Trade in Endangered Species (CITES) prohibits any trade in turtles, their shells, their eggs, or any other body part. Today, under strict protection, the Kemp’s ridley population appears to be in the early stages of recovery. Egg collection has been outlawed and nesting habitat protected by the Mexican government. The use of turtle excluder devices (TEDs) on shrimp nets is mandated on all U.S. shrimp trawlers, and since 1989, shrimp cannot be imported into the U.S. from countries whose shrimp fisheries do not use these lifesaving devices. These conservation measures have helped the Kemp’s ridley turtle rebound, with more than 20,000 nests recorded at Rancho Nuevo in Mexico in 2009, and 771 on the Texas coast. A new draft recovery plan issued for public comment by wildlife agencies of the U.S. and Mexico. Its goal: removing the turtle from the endangered list, once and for all.
Release of Kemp’s Ridley Sea Turtles: Texas Parks and Wildlife