Loggerhead Turtle (Caretta caretta)
Named for their large heads, loggerhead turtles are marine reptiles that regularly come to the surface to breathe. Their shells -- which have reddish-brown tops and yellow undersides -- reach an average length of three feet (90 cm). Watching them swim gracefully, you would never suspect that their average weight is 250 lbs (113 kg) -- some have even been known to reach 1,000 lbs (454 kg)! They are adept swimmers and travel hundreds of miles through the ocean, reaching speeds of 15 miles (24 km) per hour. Female loggerheads have been known to travel over a thousand miles to return to the beach where they hatched to lay their own eggs. Baby loggerheads, called “hatchlings,” can be a yellow to dark brown in color measuring around 2 inches (4 cm) in length. While their actual lifespan is unknown, they reach sexual maturity at approximately 35 years of age and live over 50 years in the wild.
Loggerheads are found all over the world in tropical, subtropical and temperate waters, from Newfoundland to Argentina in the Atlantic Ocean, and from Alaska to Chile in the Pacific. Oddly enough, some loggerheads inhabit murky waters such as in the Northern Gulf Coast while others prefer the crystal clear waters of the Caribbean Sea. They regularly travel long distances along the coast or in the open ocean. Occurring in the spring and summer, nesting season draws loggerheads onto secluded beaches at night. Using their flippers and snout, they dig giant holes in the sand and lay about 100 eggs, which they bury before returning to the ocean. The temperature of the sand determines the time it takes for hatchlings to emerge as well as their gender. Using the light of the moon illuminating the ocean, newly emerged hatchlings find their way to the sea. Hatchlings are believed to begin life adrift in the open ocean on a bed of Sargassum seaweed, where communities of tiny plants and animals thrive. When they have reached a length of 15 to 20 inches (40 - 50 cm), they migrate to shallow, coastal waters.
Adult loggerheads use their powerful jaws to crush and eat bottom-dwelling invertebrates. These include horseshoe crabs, mussels, sea urchins, conchs, oysters and clams. In addition, they feed on sponges, shrimp and jellyfish, whose stinging tentacles do not hurt loggerheads.
Loggerhead turtles are listed as a threatened species and their numbers are declining. They are often drowned in shrimp trawls and gill nets that prevent them from surfacing to breathe. Offshore oil and gas drilling operations are another threat that destroys their habitat and pollutes the water. As with all sea turtles, human activity, artificial lighting and development on beaches prevents proper nesting. Turtle nests are vulnerable to both human and natural predators that dig up the eggs for consumption. Emerging in the cover of the night, hatchlings must make a quick dash to the ocean to avoid predators looking for a meal. The good news is that people are trying to protect sea turtles in a number of ways, using special nets to fish, turning beach lights off during nesting season and organizing turtle protection programs.
- Turtle Trax: http://www.turtles.org/loggerd.htm
- NOAA Fisheries: http://www.nmfs.noaa.gov/prot_res/species/turtles/loggerhead.html
- National Geographic: http://animals.nationalgeographic.com/animals/reptiles/loggerhead-sea- turtle/
- Header photo by ukanda, inset photo by USFWS