The following is an account of a few things I have learned first-hand on night walks during this ‘turtle season’. I have chosen to stick to the happier part of the story but that is by no means all of it.
For a few weeks now I have been walking on Friday nights on a stretch of the beach that runs northwards from Neelankarai to the south of the Adyar estuary in Besant Nagar, Chennai:
These walks have often been exhausting but that has hardly kept me away from walking by the Bay on Friday (and sometimes Saturday) nights. Partly because I like the idea of spending a night walking by a dark sea, listening to the white waves, staring up at the twinkling stars and planets, and often bathing in the moonlight. But more so because there’s beauty to be witnessed and a lesson to be learnt in one species’ struggle for survival in these times when we are stuck in a relentless race to consume more and contribute less to the planet we call home.
The Olive Ridley sea turtles nest sporadically along the Chennai coast every year between late December and March, and in these walks by the coast, I’ve come to like these creatures in a way that is rather uncharacteristic of me, especially when it comes to reptiles. Along with SSTCN, I walk on a treasure hunt of sorts. The treasure? Turtle nests! The idea is to relocate the eggs that the turtles lay to a safer hatchery on the beach so that the hatchlings have a greater chance of survival, and of making it to their home, the sea. This exercise is necessitated by the fact that, left to their own devices, most wild hatchlings are never able to make it to the sea because of the bright lights on the beach. On starry nights, especially the moonlit ones, the surface of the sea would ordinarily carry a gleam, forming the brighter horizon towards which the hatchlings should instinctively move on emerging from the nests. However, owing to the artificial lighting on the beach, the hatchlings often move in the direction opposite to the sea, towards the land, and either starve to death or are eaten by dogs. It is to prevent the extinction of this vulnerable species that we have to relocate the nests to hatcheries in the darker parts of the beach, fenced off from the dogs, so that when the eggs hatch the hatchlings don’t go astray and are safely released into the sea. Of course, ideally we shouldn’t do this because, as Arun says, these animals have been nesting along these beaches for millions of years and to recreate and relocate the nests that the turtles know best how to make is tricky business. In our less than ideal world, though, we have to do this to ensure the hatchlings find their way home.
The key to identifying the nests is to look for a flat ‘clearing’ on the beach that the turtle makes to camouflage the nest. Also, one has to look for the turtle’s tracks, which are easier to spot because of the distinct shape of the flippers. The nest is an interesting structure, it’s neck about 20 cm deep and beneath the neck is the chamber in which the eggs are laid. The chamber is round in shape and more spacious than the neck. You could think of a flower vase with a round bottom and narrow neck to get some idea of what the shape of the nest is. Apparently, the Olive Ridleys come back to nest on the same beach where they were born, although I have no clue how they do it.
(Eggs being collected from a nest for relocation to the hatchery.)
The Olive Ridley’s eggs look like ping pong balls. The egg-shell is soft when the eggs are laid. This ensures that when the eggs fall on top of each other in the nest they don’t crack. The shell hardens in about five to nine hours from the time of the nesting, and relocation makes sense only within this five hour window. If the nest is found after the shells harden, we usually leave the nest wherever it is and watch out for the hatchlings when it’s time. Another interesting fact about turtles (and reptiles in general) is, what is known as, Temperature-dependent sex determination (TSD). The mechanism of this process is not very clear to me, so I’ll refer you to this. Our friends at Wikipedia tell us that the pivotal temperature for turtle hatchlings is about 29 degrees celsius. Eggs incubated below this temperature (28 deg C or less) yield male hatchlings and at higher temperatures (31-32 deg C) they yield female hatchlings, with a mixed bag of male/female hatchlings at intermediate temperatures. Clearly, extreme sand temperature can severely skew the sex ratio in these animals.
Olive Ridley sea turtles typically nest two to three times during the nesting season. The first nesting may have 120 to 160 eggs, second, 80 t0 120, and the third anywhere from 60 to 80 eggs. The incubation period for the eggs is roughly around 45 days.
In the early hours of the morning of February 9, around 0530 hours, I was fortunate enough to witness a turtle nesting near the Adyar estuary. We were close to the end of the walk and by the time I reached there the turtle had started nesting so I missed the part where the turtle climbs ashore to find a suitable nesting spot. While the night was making way for the dawn, most of us stood transfixed as the turtle went into a “nesting trance”:
Nesting Olive Ridley
After the turtle was done laying eggs, it was time for the ‘turtle dance’, an elaborate exercise to flatten the sand covering the nest and camouflage it. The turtle dance starts around 5 minutes into this video:
Done with the reproductive chores, the turtle made its way back to the sea. With some difficulty we managed to steer it towards the sea after it wandered around the sands for a while, perhaps confused about directions or maybe in the mood for a little stroll by the beach before going back to the usual humdrum of the sea:
‘Hello world! Here I come!’
This Sunday morning I had my first glimpse of the hatchlings. After a long dry walk (we did not find any nests), on our way back from the hatchery, a few wild hatchlings were spotted in the fishing hamlet nearby. One of them was stuck in fishing nets, and had to be carefully untangled from it. Two others were also found. However, much of the rest of the nest (a typical nest has about 100 eggs) was not found. Clearly, chances of making it to the sea if you are a hatchling born in the ‘wild’ are rather slim.
I was holding one of the hatchlings and carrying it to the clear sands near the shore so that it could make its way home when the little fellow started waving its flippers in the air, as if in excitement, “I’m flying!” That brief moment was more beautiful than any I have known in a long, long time. I have never been a big animal lover in any real sense, and I barely even deal with dogs. I have never been into wildlife, forget marine life, except looking at pictures and watching it on video. But this time it was different, perhaps because I felt relevant, and my usual indifference to animals melted away when I saw the little fellow wave its flippers. It made me happy.
When I placed it on the sand, and another volunteer stood in the water and used the torchlight to attract the hatchling towards the sea, after an initial tense moment in which it stood still, the little fella rushed towards the sea taking quick short steps, as if eager to say, “Hello world! Here I come!” Almost like a little toy that magically comes alive and rushes towards the sea on cue.
The folks at SSTCN have been doing some great work in turtle conservation and I’m quite grateful they let me walk with them during this turtle season. This was my first lesson in conservation and, hopefully, not my last.