Commonly referred to as the UK Red List for birds, this is the fifth review of the status of birds in the UK, Channel Islands and Isle of Man, published in December 2021 as Birds of Conservation Concern 5 (BOCC5). This updates the last assessment in 2015. Using standardised criteria, experts from a range of bird NGOs, including BTO, assessed 245 species with breeding, passage or wintering populations in the UK and assigned each to the Red, Amber or Green Lists of conservation concern. The same group of experts undertook a parallel exercise to assess the extinction risk of all bird species for Great Britain (the geographical area at which all other taxa are assessed) using the criteria and protocols established globally by the International Union for the Conservation of Nature (IUCN). This resulted in the assessment of 235 regularly occurring species (breeding or wintering or both), the total number assessed differing slightly from BOCC5 due to different rules on the inclusion of scarce breeders and colonisation patterns. The results of this second IUCN assessment (IUCN2) are provided in the same paper as BOCC5. Increasingly at risk This update shows that the UK’s bird species are increasingly at risk, with the Red List growing from 67 to 70. Eleven species were Red-listed for the first time, six due to worsening declines in breeding populations (Greenfinch, Swift, House Martin, Ptarmigan, Purple Sandpiper and Montagu’s Harrier), four due to worsening declines in non-breeding wintering populations (Bewick’s Swan, Goldeneye, Smew and Dunlin) and one (Leach’s Storm-petrel) because it is assessed according to IUCN criteria as Globally Vulnerable, and due to evidence of severe declines since 2000 based on new surveys on St Kilda, which holds more than 90% of the UK’s populations. The evidence for the changes in the other species come from the UK’s key monitoring schemes such as BTO/JNCC/RSPB Breeding Bird Survey (BBS) for terrestrial birds, the BTO/RSPB/JNCC Wetland Bird Survey (WeBS) for wintering populations and the Rare Breeding Bird Panel (RBBP) for scarce breeding species such as Purple Sandpiper. The IUCN assessment resulted in 108 (46%) of regularly occurring species being assessed as threatened with extinction in Great Britain, meaning that their population status was classed as Critically Endangered, Endangered, or Vulnerable, as opposed to Near Threatened or of Least Concern. Of those 108 species, 21 were considered Critically Endangered, 41 Endangered and 46 Vulnerable. There is considerable overlap between the lists but unlike the Red List in BOCC5, IUCN2 highlights the vulnerability of some stable but small and hence vulnerable populations as well as declines in species over much shorter recent time periods, as seen for Chaffinch and Swallow.

A new collaborative research study involving BTO has used GPS to track the movements of one of Europe’s rarest birds of prey, the Greater Spotted Eagle, shedding light on the pressures this species faces outside of the breeding season. Supporting our colleagues in Ukraine We have been working with Ukrainian and Belarusian colleagues in Polesia since 2019. We are appalled by Russia's invasion of Ukraine and stand in full support of those affected by this conflict. Our project partner Frankfurt Zoological Society (FZS) has been working to get partners and staff in Ukraine to safety, though most remain on-site, providing refugees with resources and supporting the protected areas’ running costs at a time when other funding has been cut off. We hope that the global support of Ukraine will help bring an end to this appalling conflict, and that we will be able to continue to work with our colleagues to learn about and protect the country’s precious habitats and wildlife. If you would like to make a donation, visit the ZFS fundraising appeal.

New research from a collaboration between BTO, Natural England and researchers at the University of Exeter has used GPS-tracking to investigate the movement behaviour of Lesser Black-backed Gulls in response to landfill closures. Gulls were found to increase their foraging effort and switch to alternative habitats following the loss of this important food resource. During the 20th century, gull populations across the globe increased rapidly in response to human activities, with the availability of waste food in landfill sites a key driver of their success. However recently, some gull populations have declined, particularly at formerly large coastal colonies, with the closure of tips likely a contributing factor. Previous gull studies have shown reductions in reproductive performance and changes in diet following landfill closures. However the implications for the birds’ movements have not previously been studied. This research used GPS-tracking data from adult Lesser Black-backed Gulls breeding at two colonies within Special Protection Areas where the species is a designation feature – South Walney, Cumbria and Ribble Marshes, Lancashire – to investigate changes in movement behaviour following the closure of major landfill sites within the birds’ foraging range. In the year after the landfills closed, breeding gulls increased their foraging effort as they had to travel further and for longer on foraging trips. They also switched to alternative foraging habitats. Gulls breeding at South Walney increased their selection of agricultural areas following landfill closures, whilst birds breeding at Ribble Marshes foraged more in nearby towns and cities. Although the long-term consequences of landfill closures for Lesser Black-backed Gulls are unclear, these results highlight how the availability of anthropogenic resources far outside protected areas may influence gull movement behaviour, highlighting the importance of spatial scale when attempting to conserve and manage highly mobile species like gulls. In the short term, gulls responded to landfill closures by switching to forage either in agricultural areas or urban habitats. These habitat switches may alter the location of human-gull conflicts, as foraging gulls in agricultural areas may steal livestock food while those in towns and cities engage in perceived nuisance behaviours such as fouling, littering and food-snatching, potentially requiring management interventions. Finally, this study highlights the value of technology such as GPS-devices as a tool to monitor rapid behavioural responses of birds to future environmental change.

New BTO research has examined the extent to which data on avian electrocutions and collisions are collected by companies responsible for high-voltage powerlines across Europe, and made recommendations to develop best practice. The continued increase in global energy demand requires expanding networks of power supply. High-voltage overhead powerlines, however, pose a collision and electrocution risk to some bird species if poorly sited or designed. Most powerline companies are legally required to mitigate these impacts, and so a range of data on bird mortality, abundance and mitigation effectiveness are often collected. But such data are not always available or accessible, preventing a wider-scale understanding of how vulnerable species may be. A new BTO paper published this week, in collaboration with RSPB, and the Renewables Grid Initiative, summarises the results of a questionnaire and workshop that brought together industry, conservationists and academics within Europe, to discuss these aspects and potential ways forward. Despite enthusiasm for sharing information, to date the task has been hampered by the lack of a centralised database, standardisation of data collection methods and data confidentiality. To overcome these barriers, a stepwise approach is suggested, developing further guidance around field methods, and collating broader information about individual studies. This approach would, in time, help unlock the full potential value of these data, reducing potential impacts on vulnerable bird populations.

In this report we show how climate change is already impacting the UK’s birds. Our internationally important breeding seabird populations and unique assemblage of upland breeding birds are already negatively affected and appear most vulnerable to future change. Many southern species and widespread resident species are increasing in response to warmer temperatures. Overall, a quarter of our breeding species appear to be negatively affected and a quarter may be responding positively; the remaining breeding species that have been studied appear relatively unaffected by climate change. There are significant gaps in our knowledge for other species, notably our wintering bird populations.