More than half of seabird species increase over 20 years in Wales latest data shows

Credit to Colin Wilkinson/RSPB Cymru
Since the census was completed, there has been a "severe outbreak" of bird flu, which has had an impact. Credit: Colin Wilkinson/RSPB Cymru

More than half of seabird species that breed in Wales have increased over the last twenty years, according to a census.

The Seabirds Count claims to be the most "comprehensive seabird census produced to date."

It took place between 2015 and 2021, providing population estimates for the 25 regularly breeding species of the UK, Ireland, Isle of Man and the Channel Islands.

Despite some increases, climate change is having an impact on seabird species in Wales. Credit: Ben Andrew/RSPB Cymru

What do the results show?

  • 11 of the 21 seabird species which regularly breed in Wales have increased;

  • That is since Seabird 2,000, the last census which was published in 2004 and covered 1998-2002;

  • Four of the other seabird species have up-to-date breeding population estimates;

  • The remaining six species have however decreased.

The population of more than 30,000 Gannets on an island off the Pembrokeshire coast has halved because of bird flu. Credit: Allan J. Perkins

It's not all good news though

The population of black-legged Kittiwakes have declined in Wales by 34%, whilst the entire Britain and Ireland population is the lowest recorded by any of the previous censuses.

European Shags are particularly impacted by severe weather events and the Welsh population has decreased by 29%.

Arctic Terns have increased by 133% in Wales, despite a 35% decline in the rest of Britain and Ireland.

"Seabird populations have been battered by the ways we use the coasts and sea," the Head of Species at RSPB Cymru said. Credit: Oli and Steph Photography

What can cause a decline in population?

  • Predation is a common problem: eggs, chicks and adults can be eaten by native and invasive predators;

  • Adverse weather conditions are causing nest sites to be swept away and making foraging conditions more difficult;

  • Increased water temperatures may reduce the availability of important food such as sandeels which leads to seabird parents not finding enough food;

Since the census was completed, there has been a "severe outbreak" of bird flu in the seabird colonies.

The island of Grassholm, just off the Pembrokeshire coast, was home to over 30,000 Gannets, but a localised census carried out this summer showed their population has halved because of bird flu.

Julian Hughes, Head of Species at RSPB Cymru said: “Seabirds Count shows the importance of the seas around Wales for nature, but the wider declines across Britain and Ireland should ring alarm bells for all those with responsibilities for the seas and our climate.

"Seabird populations have been battered by the ways we use the coasts and sea, from the introduction of predators to islands to the increasing effects of climate change.

"The success stories from this survey show that conservation efforts do work, and we need more such efforts to increase the resilience of our seabirds to changes ahead.

"Many seabirds live for decades, so it is up to us to ensure that chicks hatching this year are as successful as those of their parents’ generation."

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