Collaborative research involving BTO examines the effects of the conflict in Ukraine on the migration of the endangered Greater Spotted Eagle.

This is the 29th annual report of the BTO/JNCC/RSPB Breeding Bird Survey (BBS) and Waterways Breeding Bird Survey (WBBS), documenting the population trends of widespread UK breeding bird species during the periods 1994–2023 and 1998–2023 respectively. These are the main schemes for monitoring the population changes of the UK’s widespread breeding birds, providing an important indicator of the health of the countryside. The results are published annually as Official Statistics and used widely by Defra and the Statutory Nature Conservation Bodies (SNCBs, e.g. Natural England and NatureScot) to set priorities and to inform conservation action, and as the evidence base against which the UK’s biodiversity targets are measured. BBS data are also routinely used in research, with recent examples including peer-reviewed papers published in 2022 and 2024 which measured the efficacy of the UK’s network of protected areas in supporting wildlife. The 2023 Breeding Bird Survey Report celebrates the 30-year anniversary of fieldwork for the scheme, in particular the amazing commitment and dedication of its volunteers. It is a mixed picture for birds: Swift and Swallow show widespread decline, whereas some species are faring better, particularly in Scotland where species of scrub and woodland are doing better than in England. Download the 2023 report > Browse all editions of the Breeding Bird Survey Report >Press releases UK Northern Ireland Scotland Wales

The last few decades have seen large-scale changes in the landscapes of the UK, with most land being managed more intensively and increasingly little left for wildlife. There are some positive changes though, with habitat restoration initiatives and a greater focus on ‘landscape conservation’. This recognises that small patches of habitat, such as are found in many nature reserves, are unlikely to be enough – they need to be bigger and better connected. But in today’s crowded landscape how can this be achieved? One way to determine where habitat restoration might most usefully occur is to use computer models to predict how changing landscapes in particular areas might best benefit different wildlife groups. This collaborative paper involving BTO, led by colleagues at UKCEH, attempted to do just that by developing a computer model that can be adapted to suit different groups, including bees, bats and birds. The family of models is called the ‘4pop’ models, and that for birds is known as the ‘bird4pop’ model. These models work by simulating how individuals move, forage and breed over time, so birth (i.e. number of chicks hatched) and death rates can be estimated. This allows researchers to investigate how populations might change over time under different landscape scenarios. The bird models were set up based on the expert knowledge of authors, together with information gleaned from the published literature. The models looked specifically at three groups of birds (woodland specialists, woodland generalists and edge-nesting farmland passerines) and four individual species. The researchers then tested exactly how well the models predicted actual bird counts from BTO/JNCC/RSPB Breeding Bird Survey, based just on the habitat features present in the squares. The models did a reasonable job and, perhaps unsurprisingly, did a slightly better job for the individual species than for the multispecies groups. There is still work to be done before these models can be used in real-world decision-making situations, but they form a firm foundation, filling a gap by offering a flexible approach that can be adapted to mimic the needs of multiple species. They also allow the integration of different forms of knowledge (data from field studies, expert opinion, citizen science and standardised monitoring, alongside landcover data) to help address the challenge of promoting landscapes that are better for wildlife.

The timing of migrant birds’ arrival on the breeding grounds, or spring arrival, can affect their survival and breeding success. The optimal time for spring arrival involves trade-offs between various factors, including the availability of food and suitable breeding habitat, and the risks of severe weather. Due to climate change, the timing of spring emergence has advanced for many plants and insects which affects the timing of maximum food availability for migratory birds in turn. The degree to which different bird species can adapt to this varies. Understanding the factors that influence spring arrival in different species can help us to predict how they may respond to future changes in climate. This study looked at the variation across space in spring arrival time to Europe for 30 species of birds which winter in Africa. It used citizen science data from EuroBirdPortal, which collates casual birdwatching observations from 31 different European countries, including those submitted via BirdTrack. Using these data, the start, end and duration of spring migration was calculated at a 400 km resolution. The research identified patterns in arrival timing between groups of species, and tested whether these were linked to species traits: foraging strategy, weight, wintering location and length of breeding season. Lastly, it investigated how arrival timing was linked to temperature. The results showed that it takes 1.6 days on average for the leading migratory front to move northwards by 100 km (range: 0.6­­–2.5 days). The birds’ movements broadly tracked vegetation emergence in spring. Arrival timing could be split into two major groupings; species that arrived earlier and least synchronously, in colder temperatures and progressed slowly northward, and species that arrived later, most synchronously and in warmer temperatures, and advanced quickly through Europe. The slow progress of the early-arriving species suggests that temperature limits their northward advance. This group included aerial Insectivores (e.g. Swallow and Swift) and species that winter north of the Sahel (e.g. Chiffchaff and Blackcap). For the late-arriving species, which included species wintering further south, and heavier species (e.g. Red-backed shrike and Golden Oriole), they may need to wait until the wet season in Africa progresses enough for food to be available to them south of the Sahara before they can make the desert crossing. The research demonstrates that thanks to advances in citizen science, it is now possible to study arrival timing at a relatively fine scale across continents for a wide range of species, enabling a much fuller understanding of year-round variation between and within species, the associated trade-offs, and the pressures that species face. This knowledge can help mitigate threats to migrant species. For example, the dates of the start of spring migration could by used by each European country to inform hunting legislation. The approaches used in this work could be applied to other taxa where data are sufficient.

The Ring-necked Parakeet is a non-native species in Europe, with more than 90 established breeding populations across the continent, particularly in urban areas. The UK, and Greater London especially, is home to the largest of these non-native European populations. This study used an online survey to examine people’s perception of this species across the UK, and found that negative views of Ring-necked Parakeets are stronger in rural areas than in towns and cities.