When a turtle comes ashore to nest, she first scans the beach for a good spot to nest. Occasionally, she will turn around and go back to the sea without laying her eggs. These events are called false crawls and occur if the turtle does not find a spot she likes or if she is disturbed in the process of nesting.
When the turtle does nest, it does not always mean that she chose a good nesting spot: she may have laid her eggs in a place where they are at risk. To improve the chances of survival of such nests, we choose to move these nests either to a safer place on the beach, either to a hatchery. Here in Sal, there are four main reasons to relocate a nest:
- Predators: if the nest is laid in an area where there are many ghost crabs and/or stray dogs it is at risk of being predated upon.
- Vegetation: if the nest is too close to dune vegetation it is at risk of being destroyed by the roots of the plants.
- Water: if the nest is too close to the sea it is at risk of being drowned at high tide.
- Photopollution: if the nest is laid in a beach where there are many artificial lights, there is a risk that the emerging hatchlings will not find the sea as they are attracted to the lights (see section 2. of “Conservation”).
As an ecologist I would much prefer not having to interfere with the natural cycle of things. But as marine turtles are endangered, such conservation measures may be crucial to the survival of the species. The estimated survival rate of a hatchling to adulthood is about one in a thousand, so it is vital to protect as many nests as possible.