Disease continues to hit seabird colonies

Roseate Tern on Rockabill, Ireland (Julian Hughes)

Sites around the Irish Sea are being devastated by avian influenza this summer. All five Welsh colonies of Common Terns have been hit, with those at Cemlyn, Shotton and The Skerries reporting numbers well down, and dead adults and chicks across the sites. Arctic Terns and Sandwich Terns have died on Anglesey, and from across the water the disease has hit Rockabill, an island in Dublin Bay that is home to 1750 pairs of Roseate Terns, 60% of the whole European population. It illustrates the vulnerability of terns having so few places suitable for nesting in North Wales. A century ago, there were several dozen tern colonies but increased use of beaches by people have greatly reduced their options. This can increase disease risk and leaves few alternative sites to which they can move.

Guillemot is the latest species to test positive for bird flu on Anglesey, with dead birds and abandoned cliff ledges at several sites including South Stack, near Holyhead. Auks may also have been affected by the early summer heatwave that produced surface temperatures 4-5 degrees Celsius above normal, with unknown effects on marine creatures that form the food chain on which seabirds depend. These are just two issues that RSPB Cymru has called on Welsh Government to address in its promised Seabird Conservation Strategy.

Stormy weather at the end of last week brought Storm Petrels past Cemlyn, South Stack and Criccieth, and a Little Gull off Pen Cilan. Sandwich Tern numbers are building at roosts in Liverpool Bay, including Rhos Point and the Clwyd estuary, where colour-rings show that birds from Scotland, the Netherlands and Northumberland roost alongside those from Irish Sea colonies. Arctic Tern and Mediterranean Gull were among birds gathering at Rhos Point on the incoming tide and a Roseate Tern was with Little Terns on Gronant beach.

Two pairs of Ringed Plovers have nested on shingle at Cemlyn for the first time in many years, thanks to watchful Wildlife Trust wardens and visitors keeping dogs on leads.