SEA TURTLE NESTING BEHAVIOR

The nesting season in Broward County begins in early March each year with Leatherback sea turtles, then Loggerheads in April and then Greens in May and June. Leatherbacks are less predictable and can nest as early as February or March. Nesting continues through September, with the peak season for Loggerheads typically being the end of June and the beginning of July. With very rare exceptions, the eggs are deposited at night.

If undisturbed, the female leaves the water and crawls up the beach to a point well above the high tide line. There, using her rear flippers, she digs an egg chamber cavity about eight inches in diameter and 18 inches deep. After resting briefly, she then fills the hole with about 100 (sometimes more) ping-pong ball sized eggs, gently covers the eggs with sand and then spreads sand over a wide area with her front flippers to obscure the exact location of the chamber. She then leaves the nest site and reenters the water.

An individual Loggerhead will nest 2-3 times per year, Green female sea turtles will nest 3-4 times per year, both typically at 2-3 week intervals. Leatherbacks will nest 5-7 times per year at 10 day intervals (approximately). She will not nest every year however, but rather every other year or third year. This will depend on a number of factors including environment, food availability, genes, and parasites, for example. Greens nest with alternating extreme high (even years) and low (odd years) nesting seasons.

Since adult sea turtles do not nurture their hatchlings, the female never sees the nest site again. A single female may nest several times during a season and then not nest again for one or two years. Sometimes, (about 45% of the time), the female exits the water without digging a nest. These are called "false crawls" and usually occur because the turtle was disturbed or it could not find a "good" nest site. The crawl tracks left on the beach are always made by female sea turtles and they resemble marks left by a tractor tire. Male sea turtles never leave the ocean.

An individual turtle will nest within 5 miles to 35 miles of the region , on average, of where they hatched from and/or nested in the past, based on tagging studies. There's also evidence that the hatchlings can detect variations in the earth's magnetic field and that may be one way they navigate back.


Green Sea turtle nesting in Hillsboro beach

Stefanie Ouellette with nesting Leatherback

Leatherback depositing eggs and covering egg chamber

Leatherback hiding nest

Obscured nest


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