The loss of half of the Welsh breeding population of Gannets sees them added to Wales’ Red List.

A new (2024) review of breeding seabirds undertaken by the RSPB on behalf of Natural Resources Wales, the British Trust for Ornithology and the Welsh Ornithological Society sees Gannets being added to the Red List of Birds of Conservation Concern in Wales (BoCCW). The review shows that the population of Wales’ largest Gannet colony on Grassholm crashed by 52% as a result of the 2022/23 Highly Pathogenic Avian Influenza (bird flu) outbreak. The Grassholm Special Protection Area (SPA), a small island 11 miles off St David’s Head in Pembrokeshire, had been home to up to 34,491 pairs of Gannets in 2022. It’s one of two Gannet colonies found in Wales and was the fourth largest in the UK. Prior to 2022, Grassholm held 6% of the world population of Gannets. However, a census carried out in July 2023 by RSPB Cymru and funded by Natural Resources Wales (NRW), showed that the number of Gannets nesting on the island had plunged dramatically. In 2022, 34,491 pairs were recorded on Grassholm, but that fell to 16,482 pairs in 2023 – a 52% reduction. The population crash was due to deaths caused by the Highly Pathogenic Avian Influenza outbreak at the colony.

The new review also shows that Wales remains the most important country in the world for breeding Manx Shearwaters, with up to 64% of the global population but Manxie stays on the Amber List. Encouragingly, Black Guillemot moves to the Green List because of increased numbers in North Wales.

Anne Brenchley, Chair of the Welsh Ornithological Society said: “The addition of Gannet to the Welsh Red List shows how quickly changes in population can come about due to the spread of diseases such as HPAI.”
Rachel Taylor, Senior Ecologist BTO Cymru added: “Like most seabirds, their (Gannets) low productivity and long lives mean they recover only slowly from major challenges – and especially so in the wider context of pressures on the marine environment”.

Full details of the review, published as an update to Birds of Conservation Concern Wales in
Milvus,  can be found by following the link here. The link also includes a consolidated list of the status of all Welsh birds, following the 2024 changes.