Gently holding a blackcap warbler in his palm, ornithologist Christos Barboutis blew on its feathers to reveal the size of its belly: a good indicator of how far the bird can migrate. Acutely ...

On a remote, crescent-shaped island surrounded by crystal-clear ocean live some of the most plastic-contaminated birds in the world. They have bellies so full of fragments, they crunch when touched.

Imagine a bird landing on a peaceful island thousands of years ago. No predators. No danger hiding in the shadows. No urgent need to escape into the sky every second. Slowly, generation after ...