Guillemots, black and white birds each measuring about a foot tall, cram together on Skomer Island to starve off predators and protect their eggs, of which each reproducing bird lays just one each ...

This story appears in the November 2013 issue of National Geographic magazine. Bird cries seem to claw at the bright summer sky. The birds themselves—puffins, gannets, gulls, guillemots—whirl ...