Almost everywhere nature is under pressure. Thus, the need to monitor the state of nature and identify the many pressures affecting biodiversity has never been greater. However, the current range of biodiversity monitoring activities is varied and complex, ranging from collecting environmental DNA (eDNA) samples to structured monitoring schemes and opportunistic recording. Model-based data integration is a statistical tool to combine these different sources of data to produce robust biodiversity assessments based on more of the available evidence.

There was a significant survey effort by volunteers, NGOs and NIEA around Northern Ireland’s coastline for the last year of the Seabirds Count census period, finding that fortunes were mixed for the 20 breeding species of seabird in Northern Ireland. Fulmars continue to decline across most sites, while large gulls buck the national trends and are increasing across Northern Ireland. A team from NIEA found that Fulmar had declined at Downhill (-86%) and Binevenagh (-95%) between the Seabird 2000 census (1998-2002) and the Seabirds Count census (2015-2021), while volunteer-led monitoring of the scattered numbers along the east Co. Antrim coast showed numbers had declined by 73%. However, a rare survey visit to The Skerries by volunteers showed that numbers of Fulmar here had risen by 54% to 43 Apparently Occupied Sites. Large gulls have been increasing at most sites around Northern Ireland, with particularly good annual data collected by the National Trust for Strangford Lough. In 2021, the numbers of Great Black-backed Gulls in the lough were at their highest since 1972, with 143 nests recorded. Black Guillemots are a favourite of seabird monitoring volunteers in Northern Ireland, and we closed the census period with an incredible 80% of sites in NI covered for this species, with those sites left un-surveyed very unlikely to contain Black Guillemots. In 2021, a total of 718 Black Guillemots were counted around the coasts, with concentrations particularly high at The Maidens (60 individuals), Bangor (75 individuals), Lighthouse Island (60 individuals) and at Annalong Harbour (58 individuals). A volunteer-led productivity study found that their breeding success at Annalong was 0.5 chicks fledged per nest.

Rotational burning of vegetation is a common form of land management in UK upland habitats, and is restricted to the colder half of the year, with the time period during which burning may be carried out in upland areas varying between countries. In England and Scotland, this period runs from the 1st October to 15th April, but in the latter jurisdiction, permission can be granted to extend the burning season to 30th April. In Wales, this period runs from 1st October to 31st March. This report sets out timing of breeding information for upland birds in England, Scotland and Wales, to assess whether rotational burning poses a threat to populations of these species, and the extent to which any such threat varies in space and time.

This report presents the main findings from survey work delivered using passive acoustic monitoring devices deployed across the Bailiwick of Guernsey in 2021, the first season of the Bailiwick Bat Survey, including the first extensive baseline data for bats for the islands of Guernsey, Alderney, Herm and Sark.

Breeding waders in Britain are high profile species of conservation concern because of their declining populations and the international significance of some of their populations. Forest expansion is one of the most important, ongoing and large-scale changes in land use that can provide conservation and wider environmental benefits, but also adversely affect populations of breeding waders. We describe models to be used towards the development of tools to guide, inform and minimise conflict between wader conservation and forest expansion. Extensive data on breeding wader occurrence is typically available at spatial scales that are too coarse to best inform waderconservation and forestry stakeholders. Using statistical models (random forest regression trees) we model the predicted relative abundances of 10 species of breeding wader across Britain at 1-km square resolution. Bird data are taken from Bird Atlas 2007–11, which was a joint project between BTO, BirdWatch Ireland and the Scottish Ornithologists’ Club, and modelled with a range of environmental data sets.

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.

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.