A leatherback
Photo courtesy of Dr. Fank Paladino/Earthwatch Institute
Hola, from Las Baulas National Park in Costa Rica! "Las Baulas" means "leatherbacks" in Spanish. A narrow four-mile strip of beach in Las Baulas supports the largest nesting colonies of leatherback turtles in the Pacific Ocean. Each year the female leatherbacks come ashore from October to February to lay their eggs. However, the numbers of nesting leatherbacks at Las Baulas have dangerously declined over the past 14 years from about 1,646 nesting turtles in 1988 to 68 in 2002.

Since 1988 Dr. Frank Paladino, Dr. Richard Reina and other marine biologists have been working with Earthwatch teams to investigate the nesting habits of the leatherback turtle in an effort to save the population from extinction. The leatherback is one of the oldest living animals on earth. But surprisingly little is known about its life cycle, its behavior and the reasons for its decline.

Leatherbacks are huge! At 6 feet long, 4 feet wide, and weighing over 1,000 pounds, they are the largest reptiles in the world and travel the furthest of all of the sea turtles. Scientists have tracked their migrations from nesting areas in warm tropical areas to feeding areas north of the Arctic Circle. Leatherbacks are strong swimmers and spend most of their time in the ocean. They use their front flippers like paddles and their back ones to steer.

Their shells are soft and "leathery" instead of hard, bony ones. They feed on jellyfish and other soft-bodied animals. A floating plastic bag looks just like a jellyfish, but it will choke a sea turtle.

Beginning in October each year, the female leatherback comes to shore to nest. She crawls up at night, digs a hole in the sand, and lays 80 to 100 eggs. The eggs look like billiard balls and are soft and leathery. At dawn, the turtle returns to the sea.

The eggs hatch in about two months. Scientists can predict if the hatchlings will be male or female by the temperature of the nest. Colder temperatures produce males. Warmer temperatures produce females. Hatchlings wait until night to leave the nest. Predators, like sea gulls, would eat them during the day. The babies head for the water. When they get there, they ride out to sea.

Although it's difficult to estimate accurately scientists say that maybe one in a thousand of the hatchlings will survive to adulthood.