Are tropical seabirds, missing Gannets and dead auks a warning of the future?

Wryneck on Bardsey (Ewan Turner)

​Seabirds are tough. They deal with severe weather annually, but the last two years in northwest Europe illustrate that a changing environment can be too much even for them. Birders were thrilled to see thousands of Cory’s Shearwaters, which breed on the holiday isles off southwest Europe, move into the Southwestern Approaches and Celtic Seas. Rare tropical seabirds have been spotted, such as Red-footed Booby on Scilly and Brown Boobies as far north as Scotland, and even in the Baltic near Helsinki. But the unprecedented spectacle should worry us.

Globally, July and August were the two warmest months ever, August sea temperatures smashed records and an early summer marine heatwave saw waters around Britain up to 5°Celsius above the norm. Such big changes could have shifted the food web and left Guillemots and Razorbills struggling to find food before they head into the Atlantic for winter. Many washed up dead on beaches last month, but tested negative for avian influenza.

Yet bird flu has taken a huge toll on breeding seabirds, such as terns on Anglesey and Deeside, and Gannets in Pembrokeshire. RSPB Cymru reports that only 16,482 pairs of Gannets nested on the island of Grassholm this year, down from 34,491 pairs in 2022. The 52% reduction has set the population back more than 50 years to 1969 levels.

On land, more than a dozen Wrynecks were found in Pembrokeshire during last week’s heatwave. One made it to Bardsey, where it was still present on Monday. Small groups of Curlew Sandpipers are on the Alaw and Cefni estuaries, a Spoonbill on the Clwyd and a Dotterel was on coastal heath near Rhoscolyn. Ruffs are moving through the region, Great White Egrets are on Llyn Trawsfynydd and Llyn Traffwll, and a Black Kite was an excellent record for Bardsey.