Sea turtles travel a lot of miles across the ocean, crossing all over the sea from where they eat to where they reproduce. A lot of their reproductive cycle has to do with temperatures and environments where they know their eggs are gonna be safe, and only female turtles reach seashores to place them (even copulation occurs in the oceans). Some populations travel more than 2,000km from where they feed to where they nest while some of them stay in the same area during their entire life, with stable routes according to species.
They reach sexual maturity between 12 and 50 years of age, differing between species. This is also related to temperature conditions, as turtles live in a more or less stable temperature throughout their whole lives and its variation can even define the sex of the eggs. Maturity is usually measured by the size of their shell, which has to reach from 60 to 98 centimeters for it to occur.
Courtship and coitus happen several weeks before nesting, where female sea turtles are chased by two or more males during her fertile days. Males nail the claws they have on their front fins over female’s carapace during the mating process and, like mammals and birds, fecundation occurs inside the body of the female.
Egg Laying and Growth
Sea turtles are oviparous, which means their babies are born on eggs that are layed and hatch after certain time. In sea turtle cases, they lay their eggs on beaches between spring and summer, always at night. They dig a hole and deposit from 50 to 200 eggs thay she later covers with the sand she took away to protect them from predators, keep their temperature stable and make sure they stay clean.
Their eggs are soft and covered in mucus, and females nest every two or three years. These eggs take between 45 and 70 days to hatch, depending on the species, the size of the clutch, the humidity of the nest and the temperature, that also provides the sex of the turtles: after fertilization, lower temperatures usually produce male turtles and high temperatures give female ones.
Birth of Sea Turtles
Baby turtles break their own egg shells with their beaks and stay on the nest from 3 to 7 days before moving to the surface. They leave their refuge in smalls groups and at night, so they can avoid predators. Once they reach water, they swim nonstop from 24 to 48 hours to reach deeper waters where they can be safer.
After this moment and until they become adults, they become almost untrackable. A lot of studies have been made around the early years of sea turtle’s life, and some of them have determined that during this time they follow superficial ocean currents where they can hide and get food from floating algae, while other ones have discovered that after their 48 first hours of swimming, they hide in the ground.