Official statistic on population trends for breeding birds in the UK
This page hosts the Official Statistic ‘Population trends for breeding birds in the UK’, published on 9 April 2026.
Official Statistic description
This publication presents trends for breeding bird populations in the UK and for each UK country, showing change in population between 1994 and 2025. The statistics are based on data gathered through the BTO/JNCC/RSPB Breeding Bird Survey (BBS), which is a long-term citizen science monitoring scheme involving annual sampling at around 4,000 sites across the UK. It is the main scheme for monitoring the population changes of the UK’s common and widespread breeding birds through recording visits to randomly selected 1-km squares across the UK each spring.
The Breeding Bird Survey is a partnership between the British Trust for Ornithology (BTO), the Joint Nature Conservation Committee (JNCC), and the Royal Society for the Protection of Birds (RSPB). The BBS is indebted to the thousands of volunteer data recorders who take part each year.
The survey and analytical methods are described in the Methods section below. The Breeding Bird Survey annual report also includes the results presented here, methods, and papers published during 2025/26 that use BBS data.
Scope of Statistics
The statistic presents trends for the UK and for England, Scotland, Wales, and Northern Ireland. Trends reporting changes for 119 species in the UK between 1995 and 2024 are published using data collected from the duration of the survey (1994–2025). These trends also include data from 31 squares in the Channel Islands and Isle of Man.
Trends from 1995–2024 are reported for 116 species in England, 77 species in Scotland, and 60 species in Wales. In Northern Ireland, trends are calculated for 39 species for the period 1997–2024, using data collected between 1996 to 2025, after analytical changes were made this year (see Methods below). UK and country-level trends are also reported for more recent shorter time periods (1-year, 5-year, and 10-year).
Results
Trend tables showing the 1-year, 5-year, 10-year, and 29-year BBS species trends for the UK and for each UK country are available for download.
For related information that sits outside of the BBS official statistic, including trend tables for the English regions, the Waterways Breeding Bird Survey (WBBS), and mammal data collected through BBS, please visit the BTO website.
Summary of results
Table 1: Summary of species trends over the whole BBS period, 10 years, and 1 year for each region. The all-time trend is for 1995–2024 for the UK, England, Scotland and Wales, and 1997–2024 for Northern Ireland. See the 'Background and methods' section for details.
|
Country |
Total number of species |
All-time trend |
10-year trend |
1-year trend |
|||
|---|---|---|---|---|---|---|---|
|
Significant declines |
Significant increases |
Significant declines |
Significant increases |
Significant declines |
Significant increases |
||
|
UK |
119 |
43 |
34 |
49 |
24 |
18 |
18 |
|
England |
116 |
44 |
36 |
53 |
24 |
18 |
13 |
|
Scotland |
77 |
17 |
23 |
12 |
14 |
4 |
9 |
|
Wales |
60 |
13 |
17 |
15 |
12 |
6 |
2 |
|
Northern Ireland |
39 |
10 |
14 |
10 |
9 |
8 |
2 |
UK: Trends for 119 species
- Across the UK, 34 species have statistically significant long-term (1995–2024) increases and 43 species have significant long-term declines. Note that:
- Some species that are in decline are too rare to be robustly monitored by the BBS and so will not be included in these figures.
- Population increases include the expansion of recent colonists and non-native species.
- Of the 26 Birds of Conservation Concern (BoCC) Red-listed species with long-term trends, 20 had significant declines and none had significant increases.
- Of the 31 BoCC Amber-listed species with long-term trends, 9 had statistically significant increases and 12 had significant declines.
- As in previous years, the largest long-term increase is for Little Egret (2,748%) but note this may contain a high proportion of birds away from breeding sites. The next largest increases are for Ring-necked Parakeet (2,696%) and Red Kite (2,613%). The latter continues to expand its population and range following reintroductions in the late 1980s–1990s.
- The largest long-term declines continue to be for Turtle Dove (-98%), Willow Tit (-92%), Little Owl (-82%) and Wood Warbler (-82%).
- 24 species have statistically significant increases over the past 10 years and 49 species have statistically significant declines.
- 27 species have statistically significant increases over the past 5 years and 40 species have statistically significant declines.
- 18 species have statistically significant increases over the past year and 18 species have statistically significant declines. Note that populations generally fluctuate from year to year, although shorter-term results can be important if these build on longer-term trends.
England: Trends for 116 species
- Results in England are similar to the UK. 36 species have statistically significant long-term increases, and 44 species have long-term declines. Similar to previous years, the largest long-term increases are for Red Kite (24,950%), Ring-Necked Parakeet (2,683%), and Little Egret (2,492%). The largest long-term declines are Turtle Dove (-98%), Willow Tit (-93%), and Little Owl (-81%).
- The report highlights that, whilst many of the biggest declines continue to be seen for rare species and habitat specialists, shorter-term declines are being observed for more common and widespread species such as Collared Dove (-40% 2005–2024) and Great Tit (-17% 2014–2024).
- The report also highlights the different trends of many woodland species in different countries of the UK. Many are in decline in England (e.g. Bullfinch have declined by 43% in England) but are increasing in Scotland (55%, both 1995–2024). Other species such as Tree Pipit and Willow Warbler are in a similar position.
Scotland: Trends for 77 species
- 23 species have statistically significant long-term increases, and 17 species have significant long-term declines. The greatest long-term increases are for Chiffchaff (1,443%), Blackcap (778%) and Jay (479%). The greatest long-term declines are Greenfinch (-69%), Whinchat (-68%), and Swift (-67%)
- Of note is a 68% increase in Scottish Cuckoo populations since 1994, countering the significant declines seen across much of the Cuckoo’s range in the UK. Conversely, the Curlew is in severe decline with a 62% decline since the survey began in 1994. Other wader populations in Scotland are in a similar predicament with Lapwing (-63%) and Oystercatcher (-41%) also having declined in the long-term (1995–2024).
Wales: Trends for 60 species
- 17 species have statistically significant long-term increases, and 13 species have significant long-term declines. The greatest long-term increases are for Canada Goose (753%), Red Kite (538%) and Stonechat (411%). The greatest long-term declines are Swift (-76%), Yellowhammer (-75%), and Curlew (-74%).
- Notably, Great Spotted Woodpecker populations have increased by 20% in the past decade, contributing to a long-term increase of 246% since BBS began. Similarly, Welsh House Sparrow populations, generally in decline across the UK, have almost doubled in the last 30 years. Curlew populations, declining across the UK, are hardest hit in Wales, with a 74% decrease.
Northern Ireland: Trends for 39 species
- 14 species have statistically significant long-term increases, and 10 species have significant long-term declines. Note that these figures omit some rare and declining species in Northern Ireland that currently have insufficient BBS sample sizes in the country to be robustly monitored. These include species of farmland such as Yellowhammer, Curlew and Kestrel.
- Further to a change in baseline year from 1994 to 1996, the number of species which are considered to be in longer-term decline has increased from one to 10.
- The greatest long-term increases are for Blackcap (725%), Goldfinch (401%), and Buzzard (312%). The greatest long-term declines are for Greenfinch (-89%), Reed Bunting (-50%), and Sedge Warbler (-48%).
- Of particular interest are increases in populations of Blackbirds (36%), Song Thrush (61%) and Skylark (59%) over the last ten years. This is contrasted by other regions, with Blackbird populations falling by 12% in England over the same period.
Confidence in results and caveats
The survey and analytical approaches follow standardised peer-reviewed methods to ensure results are comparable between survey sites and over time. All data undergo a combination of automated and manual validation and verification. See Massimino et al. (2025) for full details. Some species that are in decline are too rare to be robustly monitored by the BBS. This is particularly the case in Northern Ireland, but also Wales and Scotland, which has lower sampling intensity compared with England.
Work has been carried out to assess the reliability of BBS trends, to ensure that reported trends are based on reliable data and sufficient sample sizes. This work has resulted in the following exclusions and caveats:
- We do not report population trends for 6 species of gull (Black-headed, Mediterranean, Common, Great Black-backed, Herring and Lesser Black-backed), as a large proportion of the records are of non-breeding, wintering or migratory individuals.
- Trends for rare breeding species with substantial wintering populations (e.g. Fieldfare) are excluded.
- Trends for Common Tern, Cormorant, Grey Heron and Little Egret are reported with the caveat that counts may contain a high proportion of birds away from breeding sites.
- Trends for Barn Owl and Tawny Owl are reported with the caveat that the BBS monitors nocturnal species poorly.
- Counts for 6 wader species (Oystercatcher, Lapwing, Golden Plover, Curlew, Snipe and Redshank) are corrected to exclude counts from nonbreeding flocks. Spatial filters (based on Bird Atlas distributions) are also applied to observations of Golden Plover to exclude birds outside of suitable breeding areas.
Data collection was much reduced during 2001 due to the foot-and-mouth disease outbreak and during 2020 due to Covid restrictions on fieldwork (Gillings et al. 2022), and the data collected had spatial and temporal biases. To avoid biasing subsequent results, 2001 and 2020 data are not used in the analyses. For more details, please see BBS report for 2020 (Harris et al. 2021; pp. 10–11).
Drivers of change
- Many of the historical declines in bird populations have been caused by land management changes resulting in habitat loss, a lack of suitable nesting habitat, and reduced food sources (particularly during the breeding period in spring, and over winter).
- Agri-environment options – particularly those that enhance food resources over winter – may have important positive effects on some farmland species. However, farmland bird declines are still widespread and attributable to historic changes in farming practices over the 20th century, as described in the most recent update to the UK farmland bird indicator.
- Colonisation into already available habitat is also a key reason for large increases in some species, such as Red Kite, which is recolonising after historic persecution, and the non-native Ring-necked Parakeet.
- Disease continues to play a role in the declines of some species (e.g. Greenfinch and Chaffinch, through Trichomonosis), and potentially others (e.g. Blackbird and Usutu virus). BBS, along with other monitoring schemes, will also be important for understanding impacts of Highly Pathogenic Avian Influenza (HPAI).
- The results also highlight diverging trends of some bird species in northern versus southern Britain, with population trends of 6 species of woodland and scrub increasing in Scotland but declining in England. The effects of climate change have already been implicated for one of these (Willow Warbler), and understanding changes for other species will be an important challenge.
- Population changes to UK species are not solely due to conditions on the breeding grounds. The 2024 BBS report (pp. 15, 20) highlighted recent research on two long-distance migrants – Cuckoo and Nightingale – which demonstrates the importance of non-breeding locations and migration routes in influencing population change.
- Meanwhile, the current 2025 BBS report serves to highlight the importance of local insect abundance to breeding populations. In the case of Blue Tit, BBS data was used to show that years in which moth caterpillars were more abundant led to Blue Tit population growth (Evans et al. 2024). Meanwhile, the importance of rivers and the insects they support has been shown for Spotted Flycatcher, a long-distance migrant (Eden et al. 2025, 2026).
Background and methods
Data collection
The BBS is a line-transect survey based on randomly located 1-km squares. Squares are chosen through stratified random sampling, with more squares in areas with more potential volunteers. Each 1-km square is visited twice by a volunteer between April and June, and all birds encountered while walking two 1-km line transects are recorded. 2,823 volunteers took part in the Breeding Bird Survey in 2025, covering 4,058 1-km square sites across the UK.
Data validation and verification
Data are submitted by recorders to the BBS database through an online portal. This system automatically flags any records with high counts, and unusual dates or locations for a species, notifying the surveyor of potential mistakes. Local experts review all submitted data, with closer attention paid to flagged records. These are passed onto the BBS National Organiser, who is responsible for accepting or rejecting records using supporting information from the local experts.
Data analysis
For the UK, a population trend is produced for species recorded on at least 40 survey squares on average over the trend period. For countries of the UK, trends are produced when the species is recorded on at least 30 squares on average over the trend period. Species that no longer fulfil these criteria, but that have done previously, continue to be published.
Population changes are then estimated using a log-linear model with Poisson error terms. Counts are modelled as a function of year and site effects, weighted to account for differences in sampling densities across the UK, with standard errors estimated by bootstrapping. The trend is statistically significant where the 95% confidence limits of the change do not overlap with zero.
The long-term trends cover the lifetime of BBS (1994 to 2025). 10-year, 5-year, and 1-year trends cover the most recent periods. Trends have been smoothed, and the end years truncated because at the two ends of the series the smoothed population index is very sensitive to fluctuations of the unsmoothed index. As such, although data from 1994 and 2025 are used to create the smoothed index values, the long-term trend period is presented from 1995 to 2024.
In the 2025 BBS publication, Northern Ireland trends have been calculated using a truncated time series from 1996–2025. The first two years of BBS in Northern Ireland (1994 and 1995) are excluded. These two years had very low survey coverage compared to later years and consequently lead to much larger levels of uncertainty around estimates of change. This change in baseline brings the statistic into line with existing Northern Ireland biodiversity indicators.
Methods are described in full in Massimino et al. (2025) and supporting references. Also see the BBS Report p. 16 for an overview.
Involvement and contacts
The statistic was produced by the Breeding Bird Survey partnership, with BTO having primary responsibility. Quality assurance was undertaken by BTO, RSPB, and JNCC and by ornithologists in each of the Country Nature Conservation Bodies.
The data are published as a JNCC Official Statistic. If you have any queries, please contact us.
Relation to other National and Official Statistics
This statistic forms part of a suite of statistics coming out of partnership monitoring schemes in JNCC’s terrestrial evidence programme.
The Turtle Dove statistic presented here is identical to the results first published as a separate statistic in December 2025. The earlier publication specifically for Turtle Dove is to allow use for operational purposes to inform conservation (see link for further details).
BBS statistics feed into the UK Biodiversity Indicators and country level indicators (e.g. the England Biodiversity Indicators, Scotland’s Terrestrial Breeding Birds, Northern Ireland Environmental Statistics).
References
Eden, C.F., Broughton, R.K., Donato, B. et al. 2025. Cross-system transfer of fatty acids from aquatic insects supports terrestrial insectivore condition and reproductive success. Oecologia, 207 (191). https://doi.org/10.1007/s00442-025-05827-9.
Eden, C.F., Gillings, S., Broughton, R.K., Donato, B., Hewson, C.M. & Sharp, S.P. 2026. Role of freshwater availability and terrestrial land-cover change in the distribution of a declining, terrestrial, insectivorous bird. Conservation Biology, e70219. https://doi.org/10.1111/cobi.70219.
Evans, L.C.E., Burgess, M.D., Potts, S.G., Kunin, W.E. & Oliver, T.H. 2024. Population links between an insectivorous bird and moth abundance disentangled through national-scale monitoring data. Ecology Letters, 27, e14362. https://doi.org/10.1111/ele.14362.
Gillings, S., Balmer, D.E., Harris, S.J., Massimino, D. & Pearce-Higgins, J.W. 2022. Impacts of COVID-19 restrictions on capacity to monitor bird populations: a case study using the UK Breeding Bird Survey. Bird Study, 68, 220–232. https://doi.org/10.1080/00063657.2021.2019187.
Harris, S.J., Massimino, D., Balmer, D.E., Eaton, M.A., Noble, D.G., Pearce-Higgins, J.W., Woodcock, P. & Gillings, S. 2021. The Breeding Bird Survey 2020. BTO Research Report 736. British Trust for Ornithology, Thetford.
Massimino, D. et al. 2025. ‘The Breeding Bird Survey of the United Kingdom’, Global Ecology and Biogeography, 34 (1), p. e13943. https://doi.org/10.1111/geb.13943.
Published: