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 year. On this island off the coast of Wales, nearly 100,000 of these seabirds once huddled in groups next to neighboring puffins, but the population was nearly killed off due to oil pollution and tanker traffic starting in World War II. After hitting a nadir of 2,500 in 1972, the guillemot population made a miraculous comeback over several decades, reaching 30,000 in 2022.
Then, in the summer of 2023, bird flu hit Skomer Island, killing about 15,000 birds, said Timothy Birkhead, a professor at the University of Sheffield who has spent the past 50 years studying the population. These deaths will be felt throughout the ecosystem.
