Diseases can cause animal populations to decline or even go extinct. And they’re often worsened by environmental threats caused by people.

For manatees and other hard-to-spot species, the answer may lie in the minute particles of DNA they leave behind as they move through their environments.

The death of a snail named George on New Year’s Day marked the extinction of his species. Saving the rest of Hawaii’s unique snails is a race against time — but not one without hope.

The “extinction capital of the world” could start losing unique plant species in as little as a month if funding disappears.

Introduced rabbits threatened the unique birds of Chile’s Humboldt Penguin Natural Reserve. But after a century of devastation, hope has returned.

The last 150 birds of this critically endangered species rely on humans for their survival.

Guam’s birds have been killed by invasive snakes. Now trees struggle to spread their seeds.

A new book argues, unconvincingly, that biodiversity is actually increasing.

Mosquitoes and climate change carry disease to endangered island birds. Can the threat be reversed?