Nesting

To nest, the females seek usually deserted beaches, waiting for the evening when the heat is lower, and sand is more moist, which facilitates the nesting process. The darkness alsprotects them from various dangers. This habit may also be related to the physiological constraints of maintaining body temperature, avoiding long exposure to sunlight. In some situations, however, are observed diurnal spawning, usually conditioned to the time of high tide, in places surrounded by barrier reefs, which prevent the rise of females in low tides.

When night comes, the turtles prefer to select a stretch of beach above the high-tide line.

 

When they find an appropriate location, the female digs a large body pit which can reach two meters in diameter; this is achieved using the anterior flippers in movements that involve the whole body, where she accommodates to start the nest itself.

 

They can make several body pits before choosing the ideal place to lay their eggs.

 

After the body pit is done, they dig the nest in a alternate, synchronized movement of the rear flippers, using the flippers to scoop out the sand and dig the nest chamber.

green@PT copy
D09_A_473©PT copy

The nest is about half a meter deep when the turtle is is ready to lay her eggs.

The eggs have a flexible shell, and this prevents them from breaking while they fall on top of each other.

The eggs are covered and thus protected by a kind of mucus and after laying they are covered with sand placed by the turtle.

After laying the eggs, the female covers the nest and makes a kind of a camouflage, revolving a large area of the sand surrounding the nest, using her frontal and posterior flippers, in an attempt to disguise the location from any possible predator. After the camouflage the turtle returns to the sea.

Situations such as the presence of trash in the sand, noise and / or artificial lighting (sudden or continuous) as well as other environmental factors, may discourage the presence of the female on the beach, and consequently may cause her to immediately return to the sea.

 

In these situations, the female returns shortly afterwards, sometimes in adjoining sites, to nest.

 

This behavior varies somewhat according to species and the breeding area, but it is known that in a breeding season the same female can nest between three and six times, in an internesting interval of 12 to 16 days.

Females usually do not reproduce in consecutive years. The interval between two reproductive seasons is defined as remigration interval. This period varies from species to species and even among populations of the same species. The reproductive cycles may be annual, biennial, triennial or irregular. In general the range of female remigration intervals can range between 1 and 9 years and usually varying with factors such as the availability and quality of food, environmental changes and distance from feeding and reproduction areas.

Nesting is not always carried out solitarily. A variation of this behavior is observed in the genus Lepidochelys; in some breeding areas these perform the phenomenon known as “Arribada”, where thousands of females look for the same beach to lay eggs at the same time. It is believed that such behavior may be stimulated by the release of substances (hormones), in the pores located in the ventral portion of the marginal scales, observed only in this species, encouraging other females to nest at the same time.

arribada_BivashPandav copy