Five species of turtle nest on the beaches of Sri Lanka. They are the green turtle, the olive ridley turtle, the leatherback turtle, the hawksbill and the loggerhead turtle. The primary nesting areas, on the southern to western beaches are unfortunately also where the greatest density of human population can be found. Wilpattu and Yalanational parks afford a degree of protection. Some hatcheries have been set up as tourist attractions, as the peak season and hatching coincides.
Concentrating all eggs in a single hatchery can be disastrous in the case of flooding and localized erosion and might draw greater numbers of predators, including human ones.
According to some reports, moving the eggs lowers the hatch rate by 20 to 30 percent. Fertile turtle eggs are marked with a white patch after one day of incubation and moving them after this stage greatly increases the mortality of hatchlings. Also the practice of holding hatchlings for a few days before releasing them may disrupt natural instincts. At some facilities, visitors are allowed to handle and even release hatchlings.
In some coastal regions in the USA, persons living near the beach are legally obliged to dim their lights when turtles are hatching, as researchers believe the moonlight may play a role in their imprinting. Light pollution by human civilization may interfere with that.
It is estimated that sea turtles diverged from other turtle species more than 100 million years ago. One of their distinctions lies in their inability to retract their heads and legs into their carapaces as other turtles do.
The leatherback turtle does not have a hard shell as the other six seagoing species do. Instead its carapace is made up of tough leathery skin covered with thousands of hard bony plates.
There are a few turtle terms you may not be familiar with. The nares are the openings to the nasal cavity. Brumation is another word for hibernation and the central part of a scute is sometimes referred to as the areola. Aestivation is another type of hibernation, but in this case, the cause is heat or extreme drought, rather than cold. The collective name for a group of turtles is a bale.
These are just a sprinkling of the amazing wealth of turtle facts available online or in books.
