The recent spread of Avian Influenza among threatened gulls and terns is gathering pace, say experts from the British Trust for Ornithology (BTO). At least 10,000 Black-headed Gulls, 4% of the total UK population, are feared to have died since the end of March. Hundreds of Common Terns have also died, with signs of severe losses for this species still to come. BTO researchers want members of the public to help track the spread of Avian Influenza by reporting all dead birds through both the BirdTrack app and to Defra. In Northern Ireland, dead birds should be reported both through BirdTrack and DAERA. Black-headed Gull mortalities from suspected Avian Influenza have more than doubled in the past month, with reports indicating that the new wave has spread across England and into Northern Ireland. Since the beginning of June, more than 200 Black-headed Gulls and a number of Common Terns are thought to have died from Avian Influenza at RSPB Window on Wildlife at Belfast harbour. The reserve has been temporarily closed to the public. Black-headed Gulls often nest alongside other colonial birds, including Common Terns, with this species now also impacted at sites from Norfolk to County Antrim. 40% of the 800 breeding Common Terns at Shotton Steelworks in North Wales are thought to have died from Avian Influenza, along with half of the 400 that breed at nearby Seaforth Nature Reserve. Both Black-headed Gull and Common Tern feature on the Amber List of Birds of Conservation Concern. The long-term impact of Avian Influenza on these threatened populations will not be known for some time yet. Although only a relatively small number of dead birds are tested for Avian Influenza, current sampling suggests very large numbers of Black-headed Gulls are already affected. All dead and sick birds of any species should be reported to BirdTrack, which allows researchers to follow the disease’s geographical spread and rapidly assess potential impacts on populations, and to Defra/DAERA, so that if needed, dead birds can be collected for testing. Members of the public are reminded not to touch dead or sick birds and to keep dogs on leads to prevent the further spread of disease. Professor James Pearce-Higgins, BTO Director of Science, said, “The spread of Avian Influenza through these inland breeding colonies of Black-headed Gulls and Common Terns is continuing. It represents the next phase of the battle against this virus that devastated so many of our coastal and offshore seabird colonies last year. We are only able to track the spread of Avian Influenza with the help of birdwatchers who submit their sightings to BirdTrack and Defra/DAERA, supporting the efforts of site managers and reserve wardens.” Dawn Balmer, BTO Head of Surveys, said, “Thank you to everyone who has submitted records of dead birds to BirdTrack which allows us to monitor the spread of Avian Influenza, and also to Defra/DAERA, which may collect the birds for testing. Black-headed Gulls breeding at upland reservoirs appear to be badly affected at the moment, so we urge birdwatchers to check out breeding sites they may know of and report any deaths.” Peter Coffey, Merseyside Ringing Group volunteer, said, “It is devastating to see Avian Influenza affect so many Black-headed Gulls and Common Terns at Shotton Steelworks, an important location for both species. Over a third of our adult Common Terns have already died.”

The British Trust for Ornithology (BTO) has fitted 10 more Cuckoos with state-of-the-art satellite tags, allowing scientists and the general public to track their annual migration to central Africa and back. The UK has lost more than a third of its Cuckoos in the past 25 years but the full reasons why are still unclear. Following these birds on migration will help researchers understand the pressures they face. Irish Cuckoos have been included in the project this year for the first time, as part of a collaboration between BTO and Ireland’s National Parks & Wildlife Service. Ireland’s Cuckoo population has declined by 27% since the early 1980s. Since it began in 2011, the BTO Cuckoo Tracking Project has tagged more than 100 Cuckoos. Its work has revealed that English Cuckoos migrate more often via routes associated with higher mortality than Scottish Cuckoos do. This is the first year that the project has tagged Cuckoos in Ireland, which will reveal for the first time the routes that these birds take. The differences in survival rates are linked to the conditions the birds encounter at the sites in southern Europe where they stop to refuel. The availability of large insect prey on their breeding grounds in the UK and Ireland may also impact their ability to successfully complete their migration south. Four Cuckoos were tagged in Ireland: ‘Cuach Carran’ in Burren National Park in County Clare; and ‘Cuach Cores’, ‘Cuach Torc’, and ‘KP’ near Incheens in Killarney National Park, County Kerry. In England, ‘George' and 'Michael' were tagged at Loddon Common in the Norfolk Broads, ‘Jasper’ was tagged in King’s Forest, Suffolk and ‘Trent’ was tagged at Ryall, Worcestershire. Researchers got a surprise at Knepp, Sussex, when they caught a bird they had tagged the previous year but who was presumed to have died. ‘Bluey’, as this bird was named, was fitted with a new tag alongside a new bird, ‘Sayaan’, bringing the total number of new tags deployed to 10. Anyone can follow the BTO Cuckoos on our Cuckoo migration map The next stages of the birds’ lives are not for the faint-hearted. After heading out across the English Channel and south through Europe, the Cuckoos have a Mediterranean Sea crossing to contend with before they face the Sahara, the biggest challenge of them all. Most traverse the desert in a single non-stop flight, travelling at altitudes of up to 5 km to avoid the worst of the heat. Every tagged Cuckoo provides us with invaluable data, improving our understanding of this extraordinary species and increasing the chances of developing effective conservation measures to reverse its fortunes. Dr Chris Hewson, lead scientist on the project, said, “It’s fantastic to see 10 more Cuckoos heading off with satellite tags newly fitted. These birds will help us to better understand the pressures they face, the reasons for the population declines they are undergoing in large parts of the UK and how we can help them to successfully complete their arduous migrations in the rapidly changing world we share. It’s especially exciting to see birds from Ireland tagged for the first time - we’re looking forward to learning about the migrations of these Cuckoos from the western extremity of the species’ breeding range.” Malcolm Noonan, Irish Minister of State for Heritage, said, “I am delighted that the National Parks & Wildlife Service has teamed up with BTO for this project. It will be very interesting to see the results over time. Last weekend we saw one of the birds move away from Killarney National Park towards Tipperary, and another shoot across the east Cork coast before double-backing to Limerick. It will be fantastic to get a full picture of the Cuckoos’ movements at home here in Ireland, when they migrate and, hopefully, when they return to our shores next year.”

Avian Influenza is killing large numbers of Black-headed Gulls at inland and coastal breeding colonies across central and northern England, prompting fears among scientists that a new wave of the disease could be building. Researchers from the British Trust for Ornithology (BTO) want members of the public to help track the spread of Avian Influenza by reporting all dead birds through both the BirdTrack app and to Defra. In Northern Ireland, dead birds should be reported both through BirdTrack and DAERA. More than 1,500 Black-headed Gulls are thought to have been killed by Avian Influenza at Marsh Lane Nature Reserve near Coventry, while around 800 are feared to have died at RSPB St Aidans, near Leeds, and around 250 at Rutland Water. The majority of sick or dying Black-headed Gulls confirmed to have Avian Influenza have been reported from sites between Buckinghamshire and Yorkshire, with cases also reported in Surrey and Montgomeryshire. Although only a relatively small number of dead birds are tested for Avian Influenza, current sampling suggests very large numbers of Black-headed Gulls are already affected. All dead and sick birds of any species should be reported to BirdTrack, which allows researchers to follow the disease’s geographical spread and rapidly assess potential impacts on populations, and to Defra, so that if needed, dead birds can be collected for testing. These sources indicate that more than 4,000 Black-headed Gulls have died in just the past few weeks, and that the mortality rate is increasing. This figure suggests that over 1% of the 140,000 pairs of Black-headed Gull thought to breed in the UK each year have died in the last few weeks - this in a normally long-lived species with a typical lifespan of 11 years is concerning. Worryingly, the breeding population has already been in decline for a number of years, and the species was placed on the Amber List of Birds of Conservation Concern in 2021. The impact Avian Influenza will have on this already struggling species remains unclear, but if the current rate of mortality continues it has the potential to have a large impact on this familiar and charismatic species. Black-headed Gulls nest alongside other species, such as Common Tern, Sandwich Tern and Avocet: there are concerns that these too might be affected. Similar mortalities among Black-headed Gulls were reported in France earlier this year, followed by birds in the Low Countries, Italy and Germany. Data from bird ringing show that Black-headed Gulls that breed in the UK often spend the winter in western continental Europe before migrating north, indicating a possible route of transmission. Large numbers of dead birds are now also being reported at breeding colonies in Belgium, the Netherlands, Germany, Denmark and Poland. Such widespread impacts across Europe would be likely to significantly reduce the number of wintering birds that return to the UK next autumn and winter. Members of the public are reminded not to touch dead or sick birds and to keep dogs on leads to prevent them from scavenging on carcasses. Professor James Pearce-Higgins, BTO Director of Science, said, “Last year saw Avian Influenza kill tens of thousands of seabirds at the UK’s internationally important coastal breeding colonies. The latest news about Black-headed Gulls shows that the virus is now impacting inland colonies, too. Black-headed Gulls breed at a wide range of inland water bodies, which makes them much more obvious to members of the public. Everyone can help us to understand more about the ongoing outbreak of this very worrying disease by reporting any dead birds they do see via BirdTrack and to Defra’s online portal.” Professor Phil Atkinson, BTO Head of International Research said, “The first reports of large mortalities started in the last week of March with, for example, dozens of dead birds being reported at Rutland Water and Marsh Lane Nature Reserve. Since then, the numbers of sick and dead birds has increased rapidly with reports coming in from across central England. By late April and early May, BirdTrack received the first reports of coastal sites being affected and the spread is likely to increase to other parts of the UK.”