June is the height of the breeding season for many of Britain’s seabirds, and among the best months to visit a sea-cliff colony.
Guillemots like to nest on the narrowest of rock ledges, often next to razorbills, their close cousins, and these auks squeeze together in astonishing numbers.
Tim Birkhead, who has studied guillemots for five decades at their colony on Skomer island off the coast of Wales, has recorded as many as 70 nesting adults per square metre of cliff face. This is probably the highest nesting density of any bird in the world.
One researcher colourfully compared it to bringing up a baby on the Tube in rush hour.
Each pair of guillemots lays their single egg in April or May, and by mid-June some of the chicks may be ready to fledge. This involves a perilous leap of faith into the sea far below, with their stumpy wings not yet fully developed.
Wisely, the chicks usually jump at night to avoid being attacked by marauding black-backed gulls.
Top image: Skomer, Wales. Credit: WhitcombeRD/Getty Images
More amazing stories about wildlife
- In an Australian city, birds are collecting handcuffs, medicine jars and banknotes. This is why
- "A scale that has never been documented before in Greece." Falcon snatches 8 bats from the air in just 30 minutes
- Oregon’s biggest city was drowning in crow poop. Then a new predator came to town
- “They simply moved in.” Thousands of tiny falcons are taking over this ancient Italian city
