About the Loggerhead Sea Turtle
About the Loggerhead Sea Turtle
Loggerhead turtles (Caretta caretta) are the largest of the hard-shelled sea turtles. A "loggerhead" is a heavy iron hand tool--hence the name for this turtle, which has a large, thick head and strong jaws that enable it to feed on hard-shelled prey such as conch, bivalves, crabs and whelks.
Adult loggerheads are recognized by their bulky heads, reddish-orange, heart-shaped carapace (upper shell), and creamy yellow plastron (lower shell). Upper body parts are shades of brown, and underparts are yellow to cream.
Newly hatched juveniles are 2 inches or less in length and dark olive-brown.
Adults average between 200 and 350 pounds and 3 feet in length, but some weighing more than 1,000 pounds have been noted.
Juvenile loggerheads spend the first seven to 12 years drifting the ocean currents hidden in sargassum, a type of floating seaweed. The thick mats of sargassum provide abundant food and cover. When the turtles grow large enough to discourage most predators, they migrate to coastal areas, brackish lagoons and salt marshes.
Adult loggerheads favor rocky outcroppings, coral reefs and shipwrecks. They are mostly carnivorous.
Distribution and Migration
Loggerheads inhabit all but the coldest oceans of the world. Those in cooler oceans move to tropical and subtropical waters during the winter months. Turtles tagged off the coast of the Baja Peninsula in California and Mexico have migrated 7,500 miles across the Pacific Ocean to Japan.
Loggerheads are solitary except for the breeding season. Breeding takes place in the water, but not until the turtles are 12 to 30 years of age. The female returns to her natal beach during the night, coming ashore to dig a hole in the loose sand between the high tide line and dunes. It is the only time she leaves the water. She deposits between 50 and 200 eggs, covers the eggs with sand and returns to the ocean. Females may nest two to five times during the breeding season.
Incubation temperatures determine whether embryos will be male or female. In general, 24 to 26 degrees C produces males, and between 28 and 30 degrees C produces females. Eggs outside these temperatures do not hatch. Incubation may range from 45 to 70 days.
Juvenile turtles emerge from the eggs and immediately begin a period of frenzied swimming activity. The first efforts bring them up and out of the sand nest. They immediately head for the ocean, swimming for about 24 hours to reach the offshore sargassum beds. An estimated one in 1,000 juveniles survives to adulthood.
Loggerheads are listed as an endangered species in the U.S. Because of their migratory habits, many nations share turtle conservation efforts. Protection laws vary in different countries, complicating conservation efforts. Most loggerheads are killed by drowning when they are caught accidentally in commercial fishing nets.
It is illegal to disturb a loggerhead nest on any U.S. beach, or to intentionally harm eggs, hatchlings or juvenile or adult turtles in any way.
Most beaches have strict "lights out" policies during nesting season. Hatching turtles can become disoriented by artificial lights and "swim" away from the water, where they soon perish.