Young animals are born into families which raise them from the moment they arrive while others have to fend for themselves right from the start.
For turtles, it all begins in a hole. There can be as many as a hundred eggs in that single hole. Depending on the species, incubation can last anywhere from six weeks to two months. If the nest has not been raided by a predator, the eggs will hatch. The tiny reptile breaks out of its egg using a caruncle or “egg tooth”, a modified tooth whose only function is to rupture the embryonic membrane and shell. It falls off soon after birth. Turtles emerging from the eggs are called hatchlings; from the moment they break out of their egg, they have to dig their way out of the hole and face a daunting task. Female turtles lay their eggs in holes far enough from the sea to avoid them from being flooded. Now the hatchling has to make it to sea. Most hatchlings make this journey at night, using the moonlight to guide them toward the water. They are fuelled for this long trek by left-over egg-yolk. Those that hatch too late have to make the journey by day and run a great risk of being preyed upon by seabirds such as frigatebirds circling above, vultures and other raptors, herons, stray dogs, raccoons, ghost crabs, coyotes, dingoes, etc. Humans also harvest the eggs for consumption. Thousands of hatchlings crawl across the sand towards the sea, driven by instinct but most will have their journey cut short by nocturnal predators. Once in the water, the minuscule turtle faces a different type of predator: baby sharks and other predatory fish such as giant trevallies.
There is a “lost time” from when a hatchling enters the water and when they are sighted again as juveniles, when they reach the size of dinner plates, foraging in coastal waters. It is thought that they spend these “lost years” in pelagic oceans until they are big enough to return to the coast and continue their remarkable journey. Researchers still don’t know where these turtles spend these years. Modern remote tracking methods have been unreliable due to the fact that the turtles can dive quite deep causing the tracking devices to fail.
Throughout this journey, each individual turtle is all alone and relies entirely on its instinct to make choices that will guide it to the next step in its life journey. There are no parents to follow or learn from; they just know what to eat, where to look for food and what danger they must avoid.
Depending on the species, ten to fifteen years after they hatched, sea turtles reach sexual maturity and begin breeding. Adult females return to the beach where they were born and continue the cycle. Olive Ridley and Kemp’s ridley turtles lay they eggs in synchronised mass nesting events or “arribadas” while other turtle species will lay small clutches every ten to fifteen days. During the nesting season, which can last as long as two months, the females hang around in the waters close to the nesting beach, feeding and resting and waiting for the cover of nightfall to return to land and lay their eggs.
These harmless giants are unfortunately a popular ingredient in turtle soup but also face other threats. Entanglement in fishing nets, coastal developments (leading to loss of nesting sites), plastic and marine debris, global warming and the illegal wildlife trade are the major threats to turtles.