The leatherback sea turtle, Dermochelys coriacea, is the largest living turtle and heaviest non-crocodilian reptile, reaching lengths up to 2.7 meters and weights that can exceed 900 kilograms. Its unique appearance stems from its flexible, leathery skin covering a bony matrix, rather than a hard shell, which gives the species its common name. These highly migratory marine reptiles traverse vast ocean distances.
Predators of Eggs and Hatchlings
The earliest life stages of leatherback turtles, from eggs to newly hatched individuals, are particularly vulnerable to predation. On nesting beaches, various terrestrial and avian predators seek out these defenseless stages. Raccoons raid nests, using their dexterity to unearth buried eggs. Foxes, coyotes, wild dogs, skunks, opossums, and mongooses also pose a significant threat, often digging up clutches to consume the eggs.
Crustaceans like ghost crabs are common predators, preying on both eggs and newly emerged hatchlings as they attempt to reach the ocean. Birds such as gulls, frigatebirds, and various raptors, including crested caracaras and night herons, swoop down to snatch hatchlings during their journey from the nest to the water. Monitor lizards are also documented predators, raiding nests for eggs, particularly in regions like Papua New Guinea. Eggs are immobile, and hatchlings are small and lack defense, making these periods highly susceptible to opportunistic feeders.
Threats to Juvenile Leatherbacks
As leatherback turtles grow beyond the hatchling stage into juveniles, they develop more resilience, but they remain susceptible to various marine predators. Sharks continue to pose a threat during this growth phase, with species like tiger sharks known to prey on juvenile sea turtles. Other large predatory fish, including barracudas, groupers, and requiem sharks, also present dangers to young leatherbacks in open ocean and coastal waters.
Cephalopods, such as octopi, can also prey on smaller juvenile turtles once they enter the marine environment. While their increasing size offers some protection, juvenile leatherbacks are still not large enough to deter all potential threats. Predation pressure decreases as they grow, but they are still targets for marine carnivores that cannot overpower a fully grown adult.
Predators of Adult Leatherbacks
Fully grown adult leatherback turtles possess few natural predators due to their immense size, thick leathery skin, and powerful flippers. Apex marine predators, such as large sharks and orcas, are among the only known natural threats capable of preying on adult leatherbacks.
Tiger sharks are particularly noted for their ability to prey on sea turtles, including adults, possessing jaws and teeth adapted to crush shells. Great white sharks have also been documented preying on adult leatherbacks, although such events are considered rare. Killer whales, or orcas, are marine mammals that have been observed attacking adult leatherbacks. On land, nesting female leatherbacks, despite their size, can face threats from terrestrial predators such as jaguars in the American tropics or saltwater crocodiles in regions like Papua New Guinea. However, these predation events are uncommon given the turtles’ defenses and rare encounters.