Roger Ketley’s Record of Turtle facts
Here are some fascinating facts about these endangered creatures.
If you have missed Louise and Roger Ketley’s account of their amazing adventure in Greece as part of a team of volunteers for turtle conservative, then click here:
- There are seven species of sea turtle worldwide, all descended from the Archelon, a now extinct prehistoric reptile (100 to 66 million years old); this late Cretaceous turtle grew to 4m in length, twice the size of any present-day turtle. The largest Archelon fossil, found in the Pierre Shale of South Dakota in the 1970s, measures more than 4m long, and about 5m wide from flipper to flipper.
- Sea turtle populations are under threat worldwide – a direct result of the degradation of the nesting beaches, accidental capture by fishing vessels, commercial use and pollution.
- Greece hosts about 60% of the total number of nests of the loggerhead turtle (Carreta carreta) laid in the Mediterranean. Every summer, from May to end August, hundreds of female turtles come out at night to the nesting areas of Peloponnesus – by instinct they return to the beaches of their birth, using their internal magnetic compass. There are few places in the world where this occurs and fewer in the Mediterranean. They dig an egg chamber in the sand to deposit about 120 fragile eggs the size of golf balls (about 4cm in diameter). The eggs must remain undisturbed in the warm sand for about 60 days to incubate. The temperature of the sand seems to determine the hatchlings’ sex – warmer sand makes female hatchlings more likely. From mid-July to end October, the hatchlings emerge from their nests, usually at night, and race towards the sea. It can take up to three days for the full clutch of eggs to hatch and hatchlings to exit the nest.
- A female loggerhead turtle can lay up to seven times per season, every two to three years. Sadly, even under natural conditions, an estimated one in 1,000 hatchlings reaches sexual maturity, and, for loggerhead turtles, this can take 12 to 15 years.
GVI from which can be found projects in South Africa – wildlife conservation, including Elephant research in Limpopo.