Population trends for breeding birds in the UK, to 2024

Summary of results

Table 1: Summary of species trends over the whole BBS period, ten years, and one year for each region.

UK: Trends for 119 species

• Across the UK, 36 species have statistically significant long-term (1995–2023) 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, 1 had a statistically significant increase and 22 had significant declines.
• Of the 31 BoCC Amber-listed species with long-term trends, 10 had statistically significant increases and 13 had significant declines.
• As in previous years, the largest long-term increase is for Little Egret (2,726%) but note this may contain a high proportion of birds away from breeding sites. The next largest increases are for Red Kite (2,464%) and Ring-necked parakeet (2,406%). The former 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 (-90%) and Wood Warbler (-81%).
• 24 species have statistically significant increases over the past 10 years and 52 species have statistically significant declines.
• 23 species have statistically significant increases over the past 5 years and 42 species have statistically significant declines.
• 15 species have statistically significant increases over the past year and 21 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. 35 species have statistically significant long-term increases and 41 species have long-term declines. Similar to previous years, the largest long-term increases are for Red Kite (24,725%), Ring-Necked Parakeet (2,397%), and Little Egret (2,479%). The largest long-term declines are Turtle Dove (-98%), Willow Tit (-91%), Little Owl (-78%), and Spotted Flycatcher (-71%).
• Two species have had trends in England published for the first time in this year’s BBS results: Golden Plover and Marsh Harrier. This is due to a change in analytical methods for Golden Plover and the success of conservation efforts for Marsh Harrier, boosting numbers enough to produce robust trends. The new analytical methods for Golden Plover are detailed in the BBS report.
• 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 33% in England) but are increasing by 46% or more in Scotland (1995–2023). Other species such as Tree Pipit and Willow Warbler are in a similar position.

Scotland: Trends for 77 species

• 22 species have statistically significant long-term increases and 14 species have significant long-term declines. The greatest long-term increases are for Chiffchaff (1,219%), Blackcap (714%) and Jay (472%). The greatest long-term declines are Greenfinch (-70%), Whinchat (-64%), and Swift (-63%).
• Of note is a 67% 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 15% decline in the last ten years, and a 60% decline since the survey began in 1994.

Wales: Trends for 60 species

• 17 species have statistically significant long-term increases and 15 species have significant long-term declines. The greatest long-term increases are for Canada Goose (675%), Red Kite (545%) and Stonechat (391%). The greatest long-term declines are Greenfinch (-76%), Curlew (-76%), Swift (-76%) and Yellowhammer (-75%).
• Notably, Great Spotted Woodpecker populations have increased by 20% in the past decade, contributing to a long-term increase of 240% 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 76% decrease.

Northern Ireland: Trends for 39 species

• 16 species have statistically significant long-term increases, and 1 species has a significant long-term decline. Note that these figures are likely to omit some species in decline in Northern Ireland but currently with insufficient BBS sample sizes in the country to be robustly monitored.
• The greatest long-term increases are for Blackcap (2,021%), Buzzard (1,082%) and Goldfinch (533%). The statistically significant long-term decline is for Greenfinch (-82%).
• Of particular interest are increases in populations of Blackbirds (40%), Song Thrush (68%) and Skylark (42%) over the last ten years. This is contrasted by other regions, with Blackbird populations falling by 10% in England over the same period.

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 20^th 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 High Pathogenicity Avian Influenza (HPAI).
• The results also highlight diverging trends of some bird species in northern versus southern Britain, with population trends of six 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 highlights 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.

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.
• 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 six 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 six wader species (Oystercatcher, Lapwing, Golden Plover, Curlew, Snipe and Redshank) are corrected to exclude counts from non-breeding 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 (pp. 10–11).