Haven - a predator-free seabird island in the Seychelles

A white-tailed tropicbird chick, in a nest on the ground. Photo Alison Ballance

Cousin Island, in the Indian Ocean,has always been predator-free and is a haven for rare land birds and thousands of seabirds. Photo Alison Ballance

Lesser noddies (a kind of tern) nest in trees on tropical islands. Photo Alison Ballance

Seychelles magpie robins once numbered fewer than 20 birds on a single island, but are now thriving on five predator-free islands. Photo Alison Ballance

The seeds of the tropical Pisonia tree and barbed and sticky, designed to stick to bird feathers. If a bird becomes coated with seeds they are unable to fly, and die. Photo Alison Ballance

An adult white-tailed tropicbird. Their habit of nesting on the ground makes them very vulnerable to predators. Photo Alison Ballance

White terns are widespread in the tropics. They breed at the Kermadecs, in the New Zealand region. Photo Alison Ballance

Forest interior on Cousin Island. Giant tortoises take the role of large grazing mammals and help keep the forest floor clear. Photo Alison Ballance

The Seychelles warbler once numbered fewer than 30 birds and was confined to Cousin Island. Photo Alison Ballance

Nature guide Alex Souyana and Nature Seychelle's island manager on Cousin Island, Cheryl Sanchez. Photo Alison Ballance

Thousands of lesser noddies and other seabirds breed on Cousin Island. Photo Alison Ballance