During the evening of 15 June, we sat on Bird Island’s west beach to watch the sunset and hopefully catch the first glimpse of the new moon. Both missions were successful – as the sky darkened the latter revealed itself as the tiniest sliver of a crescent.
The sky was full of birds – Brown and Lesser Noddies and Frigatebirds returning to the island and Sooty Terns returning to their nesting area, being harassed by Frigatebirds that were attempting to rob the terns of their day’s catch of fish and squid.
During this episode of our evening ritual, however, our attention was drawn to a dark shape at the sea surface towards the southern end of the beach, about 50 metres offshore. It took a while to identify it even with binoculars, but eventually a raised flipper confirmed that it was a Green Turtle, a species that nests on Bird Island during the south-east trade wind season, from May to October. Further observation revealed that there were two of them and that we were in fact witnessing an infrequently seen behaviour, a “batay torti” in Creole, which translates to “turtle battle” in English but is in reality the mating of a pair of turtles.
It was hard to make out any detail of the behaviour, apart from frequent appearances of flippers raised in the air, along with regular emergences of heads as the reptiles took breaths of air. Throughout the performance the animals remained at the surface of the water and so were always in our sight. From our first seeing them towards the south, they drifted northwards in the northerly flowing current until we eventually lost sight of them in the increasing darkness towards the northern end of the beach. In all, we saw about half an hour of non-stop mating and they were still indulging when we lost sight of them.
All this of course is a prelude to laying eggs. Females emerge from the sea usually, but not invariably, at night. They climb the beach slowly in what appears to involve a massive effort. Using their powerful flippers, they dig a nest hollow in sand at the top of the beach, sometimes sending storms of sand into the air. In the nest cavity, dug with the hind flippers, they can deposit 100 or more eggs in a process that can last an hour-and-a-half. Then follows a laborious descent of the beach to regain the open sea. After all this time-consuming and apparently ungainly activity, when they reach the water they resume their infinitely more graceful aquatic life with what appears to be a sense of relief!