Diving into Seychelles’ adventure on remote, wildlife-abundant islands

I wade through the undergrowth of Astove’s abandoned copra plantation, a Seychelles’ island, where giant tortoises hide out like a platoon of jumbo army helmets beneath the palms. The ground is otherwise the domain of hermit crabs and fallen coconuts, a tiny shell-scattered atoll. Encircling eight square miles of lagoon, land here is just a thin border between sky and ocean: a landing strip for migratory birds and nesting ground for green turtles who plough tractor-like tracks through…