UK Seabirds Decline by 70% in 50 Years Due to Climate Change and Avian Flu

6 Min Read

A comprehensive 50-year study of guillemots along the UK coast has unveiled the profound impact of climate change and avian flu on their population. Professor Tim Birkhead from the University of Sheffield led this research, revealing a stark decline of over 70% in the guillemot population since the 1970s.

A Five-Decade Study Uncovers Guillemots’ Struggles

Starting as a Ph.D. student in 1973 and now an emeritus professor, Birkhead shares startling findings that show how climate change and avian flu are affecting these seabirds.

Published as

Fifty years of Common Guillemot studies on Skomer Island” in British Birds,


this study focuses on Guillemots living on Skomer Island, off the Pembrokeshire coast, a vital seabird site in Southern Britain.

Avian Flu Takes a Toll

One of the most distressing discoveries is the devastating impact of avian flu on guillemots. Thousands have succumbed to this disease, posing an imminent threat to these birds, which have endured hardships like oil pollution and climate change.

Birkhead voices his concerns:

The ongoing bird flu outbreak poses a significant threat to Skomer’s guillemot population. Thousands have already perished, and there is a grim possibility that the situation may deteriorate further. Should avian flu persist and spread, it could potentially become one of the most devastating crises to impact the seabird population in the United Kingdom.

Quoted from

The Climate Change Connection

Apart from avian flu, the study highlights how climate change has led to a cascade of challenges for guillemots. These seabirds now breed over two weeks earlier than they did in the 1970s, primarily due to shifts in the availability of their fish prey, driven by climate-induced changes.

Climate change has also given rise to more frequent extreme weather events, particularly winter storms, resulting in mass mortality events known as “wrecks” in the seabird research community. For instance, in 2014, extreme weather off the Welsh coast led to a sharp increase in guillemot deaths.

Moreover, climate change has increased the frequency of extreme weather during guillemot breeding season, affecting breeding success. Recent major storms in May 2021 directly led to significant losses of guillemot eggs and reduced breeding success.

Birkhead emphasizes,

Over the last 50 years, I’ve witnessed how climate change is affecting how guillemots live. Changes to the climate are making it more difficult for them to breed, and find food, and increasing the number of events that threaten the population’s very existence. Mass mortality events, or wrecks, have always occurred, but they were once rare, and seabirds have evolved to cope with them. Now, their increased frequency is very worrying.


The Remarkable Lives of Guillemots

Professor Birkhead’s study also unravels the intricate social lives of guillemots. Unlike some seabirds that breed in isolation, guillemots prefer to breed openly, with about 20 pairs per square meter, defending their eggs collectively against predatory gulls and ravens.

Revealing their unique strategies, Professor Birkhead explains how they huddle together, breed synchronously, and stand firm against predators. This tight-knit approach proves exceptionally effective in warding off threats from gulls and corvids.

Guillemots are socially monogamous but rarely pass up opportunities for extra-pair copulations. Interestingly, these liaisons are initiated by males and require cooperation from females. The research discovered that approximately seven percent of chicks were fathered by a male other than the one that helped rear them.

Birkhead reflects,

Guillemots are incredibly intriguing, and that’s why I’ve dedicated five decades to studying them. These birds play a vital role in the marine ecosystem and serve as a clear indicator of our impact on the planet.

Funding Challenges Threaten Vital Research

Despite celebrating 50 years since the study’s inception in 2023, securing funding remains a major challenge, jeopardizing the future of this critical research.

Originally funded by the Countryside Council for Wales (CCW), which managed Skomer Island, the termination of funding by the newly-formed Natural Resources Wales (NRW) in 2014 was a blow to the U.K. seabird research community.

While a crowdfunding campaign in 2014, supported by generous donors, sustained the project for a year, ongoing donations from philanthropists have kept the study alive. However, additional funding is crucial to sustain this vital monitoring as Professor Birkhead moves closer to retirement.

A new generation of Sheffield scientists is now fundraising to ensure the continuity of this essential research, especially in the face of escalating threats from climate change and avian flu. The story of these remarkable seabirds continues to captivate and inspire as they navigate a changing world.

Share This Article