If this wasn't enough, climate change means that extreme weather is now more frequent during the guillemot's breeding season and is having a major impact on breeding success. Two major storms in May 2021 resulted in the direct loss of many guillemot eggs and reduced breeding success.
Professor Birkhead said,"Some seabirds spend much of their breeding season alone in a burrow, whereas guillemots typically breed out in the open, interacting continually with surrounding friends and family. I soon realized back in 1973 that the key to understandingbiology at the colony was to work out why and how they breed in such close physical contact—at an average of about 20 pairs per square meter—with their conspecific neighbors.
Guillemots are socially monogamous, forming long-term pair bonds, but males in particular rarely pass up the opportunity of copulating with a neighbor's partner, usually only when the neighboring male is absent. Professor Birkhead said,"Guillemots are endlessly fascinating, which is why I have continued to study them for fifty years. These birds are also a key component in the marine ecosystem, and to see them battered and knocked back by a succession of man-made agents is hugely depressing. Guillemots are our monitors of the quality of the marine environment. They provide a clear signal about what we are doing to the planet.