Accredited official statistics

Birds of the wider countryside and at sea

Updated 10 December 2024

Applies to England

Last updated: 2024

Latest data available: 2023

Introduction

The indicator shows relative changes in the abundance of common native birds of farmland and woodland and of freshwater and marine habitats in England. Bird populations have long been considered to provide a good indication of the broad state of wildlife in England. This is because they occupy a wide range of habitats and respond to environmental pressures that also operate on other groups of wildlife. In addition, there are considerable long-term data on trends in bird populations, allowing for comparison between short-term and long-term changes. Because they are a well-studied taxonomic group, drivers of change for birds are better understood than for some other species groups, which enables interpretation of observed changes.

The relative changes in abundances of birds presented here form an indicator for England and an equivalent indicator for the UK is published separately. Both indicators are derived from the Wild bird populations in the UK and England, 1970 to 2023, an accredited official statistic published annually. The publication includes more detailed information, including a breakdown of sub habitat specific indices and individual species trends

Data for this indicator can be found in the published datafile.

Type of indicator

State indicator

Type of official statistics

Accredited Official Statistics

Assessment of change

Measure	Time period	Long term trend	Short-term trend
All bird species	1970 to 2023	Deteriorating	Deteriorating
Farmland	1970 to 2023	Deteriorating	Deteriorating
Seabirds	1986 to 2023	Little or no change	Little or no change
Upland	1994 to 2023	Little or no change	Little or no change
Wetland	1975 to 2023	Deteriorating	Deteriorating
Wintering waterbirds	1975/1976 to 2022/2023	Improving	Deteriorating
Woodland	1970 to 2023	Deteriorating	Deteriorating

Notes on the indicator assessment

Long-term and short-term assessments of the statistical significance of these changes are made using the smoothed data to 2023. Analysis of the underlying trends is undertaken by the data providers.

Key results

The indices for different habitat breakdowns are summarised in figure 1. Each index is comprised of a different aggregation of species, specific to a given habitat. More detailed charts which include confidence intervals are presented for each habitat separately in figures 3 to 8. A summary of the key results are given below:

• A mixed picture for England bird indices over the long term: farmland birds (-63%) and woodland birds (-38%) indices show various levels of decline, whereas wetland, upland and seabirds show little change. Wintering waterbirds have increased by 78%.
• Farmland birds show greatest decline: Farmland bird populations have decreased by nearly two thirds since 1970 and 10% in the last five years.
• Woodland birds show worrying recent decline: Woodland bird populations have shown accelerated decline in the last decade, declining by 12% since 2018.
• Wintering water birds continue to decline: This index is made up of counts of over-wintering and not breeding birds. The index shows that populations more than doubled initially, but over the last 20 years there has been a steady decline, with the index decreasing by 8% since the winter of 2016/2017

Figure 1: The indices of breeding and non-breeding bird populations by habitat in England, 1970 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 1

• The indicators are based on the aggregated population trends for each habitat.
• Data for wintering waterbirds are collected over the winter which spans two years e.g. 1975/1976. These data are plotted here as a single year, taking the later part of the winter period e.g. 1975/1976 data is plotted at 1976 on the x axis.
• The wintering waterbirds index focuses on bird species that over-winter in the UK, some of which may also breed here. All other habitat breakdowns focus on breeding birds.

Individual species trends for different habitats in England

As discussed above, each habitat index is comprised of a different aggregation of species. The trends of each individual species within these habitats indices varies from some species being in strong decline to others showing little change, and others showing a strong increase over time. A summary of the variation in individual species trends observed within habitats is presented in figure 2. A summary of the key results are given below:

• Widespread species decline across habitats: across all habitats, a significant percentage of species are in decline over the long term, with farmland and marine habitats showing the highest proportions of declining species. The short-term trends continue to show declines, particularly in woodland and wetland species.

• Farmland and woodland species are under pressure: farmland species are particularly at risk, with the highest percentage of species in decline considering both time periods and relatively few in increase. Woodland species are also under significant pressure, especially in the short term, where almost two thirds of all species are declining.

• Limited evidence of increase in species: although overall the number of species increasing and decreasing in the long term is similar - a smaller percentage of species show increasing trends across most of the habitats, with the highest proportion of increasing species observed in wintering waterbirds in the long term and seabirds in the short term.

• Stability in certain habitats: across several habitats, a notable proportion of species show little or no change, including woodland and upland, which includes over half of the species over the long term. Short term habitats showing little change include farmland and wintering waterbird habitats.

• A reversal in trend for wintering waterbirds: Over the long term, almost half of all wintering waterbird populations have increased, a trend which is flipped over the short term, with a similar proportion now in decline.

Figure 2: Trends in England bird species across habitats: A comparison of long-term and short-term changes

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 2

• Each bar represents 100% of the species within a habitat.
• Each bar within a row shows the percentage of species within the indicator that are categorised as showing an increase (strong or weak increase), a decrease (strong or weak decline) or little or no change.
• Habitats are ranked by highest percentage of species in decline.
• WWB: Wintering waterbirds.

Farmland birds

Figure 3: The index of breeding farmland bird populations for England, 1970 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 3

• The indicators are based on the aggregated population trends of 19 species of farmland birds.
• The smoothed index is presented together with the 95% confidence interval (a measure of uncertainty) represented by the shaded area around the trend line.
• The unsmoothed index is presented as a dashed line.

The farmland bird index for England includes individual measures for 19 species of farmland birds, of which 12 species are farmland specialists (species that are restricted to, or highly dependent on, farmland habitats) and 7 species are farmland generalists.

Farmland bird populations have declined by 63% since 1970, with declines being stronger for farmland specialist birds than generalists. The most severe population declines occurred between the mid 1970s and the early 1990s, largely due to the negative impact of rapid changes in farmland management during this period. Although the rate of decline has slowed since this period, the populations have continued to decline at a fast rate, declining by 10% in the 5 years since 2018. The long-term decline of the farmland bird indicator in the UK has been driven mainly by the decline of farmland specialists. However, generalist species have also seen severe population declines since the mid 2000s.

Individual species trends vary, with some species populations in strong decline, some species more than doubling and other species changing very little since 1970. 53% of species have declined since 1970 and in the most recent 5 year period 53% of species have declined (see Figure 2). Examples of farmland birds in strong long-term decline include turtle dove, grey partridge, tree sparrow, corn bunting and starling.

For detailed information, including a breakdown of specialist and generalist farmland specific indices and individual species trends, see the farmland bird section in the Wild bird populations in the UK and England publication.

Woodland birds

Figure 4: The index of breeding woodland bird populations for England, 1970 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 4

• The indicators are based on the aggregated population trends of 34 species of woodland birds.
• The smoothed index is presented together with the 95% confidence interval (a measure of uncertainty) represented by the shaded area around the trend line.
• The unsmoothed index is presented as a dashed line.

The woodland bird index for England includes individual measures for 34 species of woodland birds, of which 22 species are woodland specialists (species that are restricted to, or highly dependent on, woodland habitats) and 12 are generalists.

Woodland bird populations have declined by 38% in England since 1970. The rate of decline has been relatively continuous over most of this period, but has accelerated over the last decade, declining by 12% in the 5 years since 2018. The long-term decline of the woodland bird indicator in England has been driven mainly by the decline of specialist species. However, the increased rate of decline observed in the last 10 years has been driven by declines in populations of the generalist and specialist species alike.

Individual species trends vary, with some species populations in strong decline, some species more than doubling and other species changing very little since 1970. 32% of woodland species have declined since 1970 and in the most recent 5 year period 62% of woodland species have declined (see Figure 2). Examples of woodland birds in strong decline include willow tit, marsh tit, wood warbler, lesser redpoll, tree pippit, lesser spotted woodpecker and spotted flycatcher.

For detailed information, including a breakdown of specialist and generalist woodland specific indices and individual species trends, see the woodland bird section in the Wild bird populations in the UK and England publication.

Water and wetland birds

Figure 5: The index of breeding water and wetland bird populations for England, 1975 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 5

• The indicators are based on the aggregated population trends of 26 species of breeding water and wetland birds.
• The smoothed index is presented together with the 95% confidence interval (a measure of uncertainty) represented by the shaded area around the trend line.
• The unsmoothed index is presented as a dashed line.

The England breeding water and wetland bird index includes individual measures for 26 species. The index can be disaggregated into four sub-habitat indicators: birds of fast flowing water (4 species); birds of slow and standing water (6 species); birds of reedbeds (4 species) and birds of wet grasslands (8 species).

The breeding water and wetland bird populations have experienced little to no change since 1975. However, more recently they have declined by 7% over the past five years. Within the index, there was a great deal of variability.

Individual species trends vary, with some species populations in strong decline, some species more than doubling and other species changing very little since 1975. 27% of wetland species have declined since 1975 and in the most recent 5 year period 62% of wetland species have declined (see Figure 2). Examples of breeding water and wetland birds in strong decline include yellow wagtail in the long-term and lapwing, dipper, coot, and tufted duck in the short term.

For detailed information, including a breakdown of sub habitat specific indices and individual species trends, see the Water and wetland bird section in the Wild bird populations in the UK and England publication.

Seabirds

Figure 6: The index of breeding seabird populations for England, 1986 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 6

• The indicators are based on the aggregated population trends of 11 species of seabirds.
• The smoothed index is presented as a solid line and the unsmoothed index is presented as a dashed line. No confidence intervals are available.

The England breeding seabird index includes individual measures for 11 species, of which 5 species are surface feeders and 4 are subsurface feeders. Trends for the seabird indicators should be interpreted with care due to the relatively small number of species included in some indices and the scarcity of data for some constituent species. The England index is strongly influenced by the inclusion of gannet, reliable trends of which are not available for the UK overall.

Seabird populations have experienced little to no change in England in the 5 years since 2018 and over the long term since 1986.

Individual species trends vary, with some species populations in strong decline, some species more than doubling and other species changing very little since 1986. 36% of seabird species have declined since 1986 and in the most recent 5 year period 27% of seabird species have declined (see Figure 2). Examples of seabirds in strong decline include herring gull.

Data collection for seabirds was impacted by the COVID-19 pandemic and trends in some seabird species have been negatively impacted by the onset of Highly Pathogenic Avian Influenza (HPAI) since 2020. However, it is unlikely that the full effect of HPAI can be seen from the data currently available.

For detailed information, including a breakdown of sub-habitat specific indices and individual species trends, see the seabirds section in the Wild bird populations in the UK and England publication.

Upland birds

Figure 7: The index of breeding upland bird populations for England, 1994 to 2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 7

• The indicators are based on the aggregated population trends of 28 species of upland birds.
• The smoothed index is presented together with the 95% confidence interval (a measure of uncertainty) represented by the shaded area around the trend line.
• The unsmoothed index is presented as a dashed line.

The upland bird index for England includes individual measures for 28 species of upland birds, of which 12 species are upland generalists, 12 species are upland specialists (species that are restricted to, or highly dependent on, upland habitats) and 4 species are upland riparian.

Upland bird populations have experienced little or no change in the 5 years since 2018 and over the long term since 1994.

Individual species trends vary, with some species populations in strong decline, some species more than doubling and other species changing very little since 1994. Overall, 29% of upland species have declined since 1994 and in the most recent 5 year period 48% of upland species have declined (see Figure 2). Examples of upland birds in strong decline include peregrine falcon, redshank, twite and whinchat.

For detailed information, including a breakdown of generalist, specialist and riparian upland specific indices and individual species trends, see the upland bird section in the Wild bird populations in the UK and England publication.

Wintering waterbirds

Figure 8: The index of wintering waterbird populations for England, 1975/1976 to 2022/2023

Source: British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB), and the Joint Nature Conservation Committee (JNCC).

Notes about Figure 8

• The indicators are based on the aggregated population trends of 40 species of wintering waterbirds.
• Data for wintering waterbirds are collected over the winter which spans two years e.g. 1975/1976.
• The smoothed index is presented as a solid line and the unsmoothed index is presented as a dashed line. No confidence intervals are available.

The wintering waterbird index for England includes individual measures for 40 species of wintering waterbirds, of which 14 species are waders and 26 species are wildfowl.

Wintering waterbird populations have increased by 78% in England since the winter of 1975/1976 and have declined by 8% in the 5 years since the winter of 2017/2018.

Individual species trends vary, with some species populations in strong decline, some species increasing 10 fold and other species changing very little since 1975/1976. Overall, 48% of species have increased and 12% of species have declined since 1975/1976. However, in the most recent 5 year period 42% of species have declined (see Figure 2). No wintering water birds are in strong decline long term, but over the short term examples include Bewick’s swan and scaup.

Like seabirds, wintering waterbirds have been impacted by the Highly Pathogenic Avian Influenza (HPAI) outbreak. The long term impacts on wintering populations of ducks, swans or geese are currently unknown.

For detailed information, including a breakdown of waders and wildfowl indices and individual species trends, see the wintering waterbird section in the Wild bird populations in the UK and Englnad publication.

Further detail

The indicator has been compiled in conjunction with the British Trust for Ornithology (BTO), the Joint Nature Conservation Committee (JNCC), the Royal Society for the Protection of Birds (RSPB), and the Wildfowl and Wetlands Trust (WWT). Data are obtained from a wide range of sources, principally:

• the Common Birds Census (from 1966 to 2000);
• the BTO/JNCC/RSPB Breeding Bird Survey (from 1994 to 2022);
• the BTO/ Waterways Bird Survey (from 1974 to 2007);
• the BTO/JNCC/RSPB Waterways Breeding Bird Survey;
• the BTO/RSPB/JNCC Wetland Bird Survey with support from the Environment Agency (from 1998 to 2022) counts (from 1975 to 1976 and 2019 to 2020);
• the BTO Goose & Swan Monitoring Programme in partnership with the JNCC and NatureScot;
• the Seabird Monitoring Programme (from 1986 to 2019);
• the Periodic Seabird censuses supplied by JNCC, RSPB, the Seabird Group, SOTEAG (Shetland Oil Terminal Environmental Advisory Group) and other partners;
• Monitoring of scarce and rare breeding birds by the Statutory Conservation Agency and RSPB Annual Breeding Bird Scheme (SCARABBS) and the Rare Breeding Birds Panel (from 1970 to 2018);

Relevance

Bird populations have long been considered to provide a good indication of the broad state of wildlife. Birds occupy a wide range of habitats and there are considerable long-term data on changes in bird populations, which help in the interpretation of shorter-term fluctuations in numbers. As they are a well-studied taxonomic group, drivers of change for birds are better understood than for other species groups, which allows for better interpretation of any observed changes. Birds also have huge cultural importance and are highly valued as a part of England’s natural environment by the general public.

Web links for further information

• Birds of Conservation concern Summary leaflet
• The Breeding Birds Survey Report
• Indicators of wild bird populations
• Waterways Breeding Bird Survey
• Wetland Bird Survey
• Populations of wild birds 1970–2022
• Seabird Monitoring Programme
• State of UK’s Birds 2020
• Waterbird Monitoring

Acknowledgements

Thank you to the many people from the BTO, RSPB and WWT who have contributed by providing data and to the many colleagues who have helped produce this indicator.

Technical annex

Methodology

The measures for each habitat breakdown of birds show the relative abundance of aggregated groups of species. Within the measures, each species is given equal weighting, and the annual index is the geometric mean of the individual species indices for that year. Populations of individual species within each measure may be increasing or decreasing irrespective of the overall trends. The individual species indices are largely derived by the modelling of sampled survey data, and estimates are revised when new data or improved methodologies are developed and applied retrospectively to earlier years. Further details about species and methods can be found on the British Trust for Ornithology website and by downloading the associated technical report.

A table listing the species that are included in each index can be found in the datasheet. For each species, an estimate of change in the long term and in the short term is given, as well as an assessment of whether the species trend is increasing or decreasing.

The year-to-year fluctuations in each measure reflects the observed changes in the survey results, and smoothed trends, which are used with their confidence intervals to formally assess the statistical significance of change over time. Smoothed trends reduce short-term peaks and troughs resulting from, for example, year-to-year weather and sampling variations.

Data from surveys of wintering waterbirds are based on full counts on wetland and coastal sites of markedly varying size. This means the standard bootstrapping methods used to estimate confidence intervals for the farmland, woodland and wetland indices, which are based on standardised sample-based surveys, cannot be applied. Assessments of change for the waterbird index are therefore made using a ‘5% rule’. If the index has increased or decreased by greater than or equal to 5%, the index is assessed as improving or deteriorating respectively. For seabirds, for which there are more gaps and variability in the underlying data, the threshold is set at 10%.

Composite indicators can mask a lot of variation among the species within them. The bar charts provided alongside the headline chart shows the percentage of species within that indicator that have increased, decreased or shown little change. Whether an individual bird species is defined as increasing or decreasing has been decided by its rate of annual change over the time period (long or short) of interest. If the rate of annual change would lead to a population decrease of 50% (halving), or a population increase of 100% (doubling) or more over 25 years, the species is said to have shown a ‘strong decline’ or a ‘strong increase’ respectively. Rates of change less than these but above +33% (increase) or below -25% (decrease) are labelled ‘weak’. Asymmetric thresholds are used for declines and increases to represent symmetrical proportional change in an index. These thresholds for decline are based on the rates used in the Birds of Conservation Concern status assessment for birds in the UK. Note that for most species, particularly over the longer period, the change is statistically significant.

Development plan

Since our previous publication we have adapted the language and visualisations used in this indicator. We are keen to hear from our users about these changes, as well as our published development plan, please email us.

References

• Fewster, R. M., Buckland, S. T., Siriwardena, G. M., Baillie, S. R. and Wilson, J. D. (2000). Analysis of population trends for farmland birds using generalized additive models. Ecology, 81, pp. 1970 to 1984.

• Freeman, S.N., Noble, D.G., Newson, S.E. and Bailie, S.R. (2003) Modelling bird population changes using data from the Common Bird Census and the Breeding Bird Survey. BTO research report no. 303. BTO, Thetford.

• Gregory, R.D., Gibbons, D.W., Impey, A. and Marchant, J.D. (1999) Generation of the Headline Indicator of Wild Bird Populations. BTO research report 221. BTO and RSPB, Thetford.

• Harris, S.J., Massimino, D., Gillings, S., Eaton, M.A., Noble, D.G., Balmer, D.E., Procter, D. and Pearce-Higgins, J.W. and Woodcock, P. (2018). The Breeding Bird Survey 2017. BTO Research Report 706. BTO, Thetford.

• Noble, D.G., Newson, S.E., Banks, A. and Gregory, R.D. (2003a) Effect of transition from CBC to BBS on Wild Bird Indicators. BTO and RSPB report to Defra.

• Noble, D.G., Newson, S.E. and Gregory, R.D. (2003b) Production of the 2002 Farmland PSA indicators. BTO and RSPB report to Defra.

• Noble, D.G., Newson, S.E. and Gregory, R.D. (2004) Approaches to dealing with disappearing and invasive species in the UK’s indicators of wild bird populations. BTO and RSPB report to Defra.

• Renwick, A.R., Johnston, A., Joys, A., Newsom, S.E., Noble, D.G. and Pearce-Higgins, J.W. (2012) Composite bird indicators robust to variation in species section and habitat specificity. Ecological Indicators, 18, 200–207.

• Tremlett, C.J., Morley, N., and Wilson, L.J. (2024). UK seabird colony counts in 2023 following the 2021-22 outbreak of Highly Pathogenic Avian Influenza. RSPB Research Report 76. RSPB Centre for Conservation Science, RSPB, The Lodge, Sandy, Bedfordshire, SG19 2DL. ISBN: 978-1-905601-72-1

• Underhill, L.G. and Prŷs-Jones, R. (1994) Index numbers for waterbird populations. I. Review and methodology. Journal of Applied Ecology, 31, 463–480.

• Woodward, I.D., Massimino, D., Hammond, M.J., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H.,Barimore, C., Dadam, D.,Eglington, S.M., Marchant, J.H., Sullivan, M.J.P., Baillie, S.R. and Robinson, R.A. (2018). BirdTrends 2018: trends in numbers, breeding success and survival for UK breeding birds. Research Report 708. BTO, Thetford.