Leatherback Turtle Nesting

KEEPING Watch: To protect the leatherback turtles (above) at Las Baulas National Park in the northwestern province of Guanacaste, efforts by nonprofit conservation group MarViva and other groups include operating hatcheries (below, with Spanish biologist Pilar Santidrián) and working to combat poaching. At left, night falls at the park, beginning the hours when turtles move up onto the beach to lay their eggs.