FAMILY: Cheloniidae

DESCRIPTION: Loggerhead sea turtles are named for their large heads, which contain powerful jaws and a thick beak. An adult loggerhead's top shell is slightly heart-shaped with a reddish-brown color; the bottom shell is pale yellow. These turtles have extremely efficient, short flippers. Adults weigh approximately 250 pounds with shells measuring three feet long.

HABITAT: Loggerhead sea turtles inhabit three distinct ecosystems during their lifetimes. They are born on land and spend their time as post-hatchlings lingering in areas near the nesting beach. Eventually, post-hatchlings are transported by ocean currents farther offshore into deeper waters where they spend the next seven to 12 years, after which they return to coastal areas and continue maturing until adulthood.

RANGE: Loggerhead sea turtles occur throughout the temperate and tropical waters of the Atlantic, Pacific, and Indian oceans. In the Atlantic Ocean, they range from Newfoundland to Argentina. Loggerhead sea turtles in the North Pacific nest in Japan but cross the Pacific Ocean to feed off the coast of North America near Baja, Mexico.

MIGRATION: In the North Pacific, turtles are born in Japan, cross the entire basin, and spend their adolescence off the coast of Baja and southern California. They return to Japan at age 20 or so to nest, with annual travels around the Pacific thereafter. In the North Atlantic, Florida nesters wander up the East Coast each year, returning to nest in the summer. Other populations breed in the Mediterranean, South Pacific, and Indian oceans, and migrate extensively across these oceans.

BREEDING: Loggerhead sea turtles reach sexual maturity around age 30, and they mate at sea. Females return to their own nesting beaches to lay several clutches of eggs between May and August, burying the eggs in coarse sand above the intertidal zone. Depending on temperatures, eggs incubate for 45 to 95 days. Hatchlings emerge at night and immediately begin a period of frenzied activity to avoid waiting predators, racing from nest to surf.

LIFE CYCLE: A loggerhead's lifespan is estimated to be up to 100 years.

FEEDING: Loggerhead sea turtles feed on sponges, jellyfishes, sargassum weed, small gastropods, clams, horseshoe crabs, and other bottom-dwelling invertebrates. Coral reefs and shipwrecks can be popular feeding areas.

THREATS: The primary threat to loggerhead populations is incidental capture in fishing gear, particularly longlines and gillnets. Other dangers include coastal development, global warming, beachfront lighting, increased nest predation, pesticides, collisions with watercraft, oil and gas exploration, and human consumption.

POPULATION TREND: Pacific populations of loggerhead sea turtles have declined by more than 80 percent in the last 25 years, with fewer than 1,000 females returning to their natal beaches to nest each year. Atlantic and Indian Ocean populations are also declining. The current total estimate of loggerhead sea turtles is around 50,000, whereas the species once numbered several million throughout the world's oceans.

Photo courtesy Flickr/Brian Gratwicke