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Sue Almond writes...about her experience while volunteering in Costa Rica.We set off on patrol usually in a group of 3, anytime between 7pm and midnight, depending on when high tide is, for a shift of 3-5 hours. No-one else is allowed on the beach at night, so it's really quiet, apart from the sounds of crickets etc in the bushes behind the sand dunes, and the waves crashing on the beach. You can't wear any mosquito repellant, as it also repels the turtles (!) so I wear long trousers, long sleeved top and 2 pairs of socks (no shoes) in a vain attempt to stop getting bitten. It's only about a 5 min walk to the "turtle beach" but you also have to canoe across a river estuary to get there. It's all very exciting and you feel like you're on some kind of secret mission! The sky is unbelievably starry and the moon is so bright, like a giant torch, and it's so beautiful the way it lights up the sea, quite breathtaking in fact. The beach is about 3/4 mile long, and we walk the length of it, checking for turtles all the time. When we get to the end, we sit down for 20 minutes, then walk back to the other end. We sit there for 20 minutes, then walk back again, etc etc..... This continues throughout the shift (3 to 5 hours), it might sound boring but i do enjoy it, it's peaceful, calm and beautiful, and there's always the prospect of seeing a turtle. And it's wonderful exercise too! When you do see a turtle it's so exciting. It first of all looks like a rock, then you realise it's gradually moving up the beach, usually to just beyond the high tide line. All the ones I've seen so far have been leatherbacks, and they are huge. The "shell" is 5 or 6 feet long, then you have the head, tail & flippers on top of that. They're the biggest marine reptile in the world. When the turtle gets to her chosen spot she first of all digs what's called a "body pit" with her graint front flippers (they're about 4 foot long). This body pit is a hollow about a foot or 2 deep, and the size of the turtle; she digs it so she can get herself into position to be able to dig the egg chamber. The digging of the egg chamber is, I think, probably the most incredible part of the whole process. It's a hole about 3 feet deep and a foot in diameter, and the turtle digs it with her back flippers, using them almost like human hands, carefully picking up each "flipper full" of sand and depositing it outside the hole. But that's not all.... because she lays about 100 eggs, the hole wouldn't be wide enough for them all, so she makes more space by carefully extending the bottom of the hole by digging out the sides, kind of like an upside down "T". The skill in doing this is amazing, you can see her carefully feeling how big the hole is with her flippers, patting down the sides so it doesn't cave in, and scooping out the sand using her flippers like hands. It would be hard enough for a human to do this, in fact I doubt I could! And the fact that it's all done with her back flippers, so she can't see what she's doing at all, makes it all the more incredible. When she's happy with the egg chamber she starts to lay her eggs. It's usually my job to count them so I have to lie face down, flat on the sand, with my head almost in the body pit. With one hand I hold one of her flippers to one side so I can see the eggs emerging, and then I put my other hand (with a rubber glove on) underneath her so that the eggs drop into my hand first and I can count them, before letting them drop into the bottom of the egg chamber. They lay approx 100 eggs, roughly 2/3 big eggs, which are the fertile ones, and 1/3 small eggs, which are infertile but just as important because they help keep the temperature correct for the fertile ones. The fertile eggs are about 2" in diameter, the infertile ones 1"or less. When the turtle's finished laying her eggs she then fills in the chamber. She doesn't just push the sand back in though, she pats in down firmly, using her flippers like hands again, and really takes her time over it. So we know where she's laid them, we hold a piece of string weighted down with a bit of wood at one end, and a metal tag at the top end sticking out of the sand as a marker (thats a really clumsy description but I expect you know what I mean). The next stage is for the turtle to camoflage the whole nest, and you have to get out of the way fast unless you want to be completely covered in sand and camoflaged yourself! She uses her front flippers to flick all the sand around and generally mess it up all around the nest so that predators can't find it. She takes ages doing this and shifts huge amounts of sand around. She covers quite a large area and you really wouldn't have a clue where the eggs were (if you hadn't cunningly marked it with the string & tag first). In fact, the first time I saw it happen I realised afterwards I'd put down my bottle of water, and didn't have a hope in hell of finding it afterwards as it was completely buried somewhere! When the turtle's finally finished camoflaging the nest, she lumbers back into the sea again. The whole process takes between 1 and 2 hours and, as I keep saying, it's absolutely incredible to watch. The fact that it's all done by instinct, no one teaches them how to do it, is one of the wonders of nature I suppose - as is the fact that they swim the oceans for years on end but always come back to the exact same beach where they were born to lay their eggs. (If only I had their sense of direction....!) As well as counting the eggs, we take all kinds of details and information - measurements of the "shell" (leatherbacks don't really have a shell, just a kind of thick leathery covering - hence the name), any distinguishing features or marks, such as injuries to flippers (they usually have a few bites or chunks missing from them). We also note down the exact time that she st arts each part of the process, where exactly on the beach she laid her eggs, what position her body is relative to the sea, etc. We also have a kind of bar code scanner thing whcih we use to find out whether she's been previously tagged (they nearly always have been) and we make a note of the "bar code" number. |
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Climb Everest In October 2006 you have the opportunity to raise money for the Nepali Children's Fund. We're climbing the Base Camp of Mount Everest and you have the opportunity to join us.