The Life Cycle of a Sea Turtle

Scientists believe some sea turtle species may live for up to a century in the open ocean. In fact, only female sea turtles leave the ocean at all, and then, only to lay eggs. Naturally shaped for sea life, their forceful flippers and large, efficient design equips them for long-distance travel and deep dives.

  1. Mating

    • Adult males and females migrate---sometimes thousands of miles---to their own hatching and foraging area off shore from a nesting beach for mating. Sea turtles are not monogamous. Females may mate with multiple males, storing sperm for later fertilization.

    Nesting

    • At nesting season intervals of every two to four years over a lifetime, females move to the shallow-water areas to forage. At night, to avoid the sun's heat, the female crawls out of the water to dig a nest in the sandy beach. She digs a pit with her front flippers for her body, then an egg chamber with her rear flippers, repeating the process until she is satisfied with the nest's conditions. She lays and fertilizes a clutch of eggs every two weeks or so until she has laid all her eggs---up to nine clutches of eggs each nesting season. Depending upon the species, that means 50 to 130 sphere-shaped eggs. She fills the nest with sand and moves offshore to forage.

    Hatchlings

    • A hatchling's gender depends upon sand temperature. Warmer sands produce more females, while cooler sands produce more males. Hatchling turtles emerge at about seven to 12 weeks, depending upon environmental conditions and species, and wait beneath the sand's surface until the nightfall temperature drop, when they push through the sand as a group and move to the sea. Once in the water, they swim with the currents toward deeper waters offshore.

    The Lost Years

    • Hatchlings remain in the ocean, following complicated innate migratory feeding patterns for up to 20 years. Scientists know little about their movements during these years and so refer to this time as the lost or pelagic (open ocean) years.

    Eating Habits

    • A species' jaw structure determines if the sea turtle is carnivorous (eating shrimp, sponges, squid), herbivorous (eating sea grass or algae), or omnivorous (both meat and plant eating). As they mature, some species change from herbivorous to mostly carnivorous.

    Maturity

    • Turtles turn to coastal waters at the end of the pelagic stage. They fully mature at age 25 to 40, spending their lives foraging, mating and migrating over expansive oceanic areas.