Accredited official statistics

5 – Farmland species

Updated 7 May 2024

Applies to England

Data last updated: November 2023

Latest data available:

• Breeding birds on farmland (National Statistics) - 2022
• Butterflies of the wider countryside on farmland - 2022
• Bat populations - 2022
• Abundance of farmland plant species (Official Statistics in Development) - 2022

Introduction

This indicator shows relative changes in abundance of species in the farmed landscape. Farmland refers to the large proportion of England which is devoted to agriculture and consists of crops or grasslands for grazing. Farmland also provides semi-natural habitats such as hedgerows and field margins that provide food and shelter.

Type of indicator:

State indicator

Assessment of change in the abundance of species in the wider countryside (farmland)

Breeding birds on farmland (National Statistics):

• Long term (1970 to 2021): Deteriorating
• Short term (2016 to 2021): Deteriorating
• Latest year (2021 to 2022): Decreased

Butterflies of the wider countryside on farmland:

• Long term (1990 to 2022): Little or no overall change
• Short term (2017 to 2022): Little or no overall change
• Latest year (2021 to 2022): Decreased

Bat populations:

• Long term (1999 to 2020): Improving
• Short term (2015 to 2020): Improving
• Latest year (2020 to 2022): Decreased

Abundance of farmland plant species (Official Statistics in Development)

• not assessed

Notes about the indicator assessment:

• To better capture patterns in the data, where possible, long-term and short-term assessments are made on the basis of smoothed data, with analysis of the underlying trends being performed by the data providers.
• Due to differences in the methods used to produce smooth trends for birds, butterflies and bats, the long-term and short-term assessments are made on varying time frames.
• All latest year assessments are based on unsmoothed data to the latest year available.
• The bat data was severely impacted by the COVID-19 pandemic, and so the 2021 bat index value has been estimated using imputed data for that year, and so has been excluded from the assessments of change, for more information see Widespread bats section below.

Breeding birds on farmland (National Statistics)

Trend description for Figures 5.1 and 5.2

In 2022 England farmland bird index was 61% below its 1970 value (Figure 5.1). The majority of this decline occurred between the late 1970s and the 1980s largely due to the negative impact of rapid changes in farmland management during this period. The decline has continued at a slower rate more recently; the index showed a decline of 7% in the short term.

Figure 5.1: Trends for the abundance of breeding birds on farmland in England, 1970 to 2022

Download the data for Figure 5.1 in ods format

Figure 5.2: Long-term and short-term changes in individual species trends for breeding birds on farmland in England, 1970 to 2021

Download the data for Figure 5.2 in ods format

Notes about figures 5.1 and 5.2

• This indicator is taken from the Defra National Statistics publication Wild bird populations in England.
• This indicator includes individual measures for 19 species of farmland birds.
• Figure 5.1 shows the unsmoothed trend (dashed line) and the smoothed trend (solid line) together with its 95% confidence interval (shaded area).
• Figure 5.2 shows the percentage of species within the indicator that have increased, decreased, or shown little change, based on set thresholds of annual change.
• Figure 5.2 is presented as a stacked bar chart and the legend is presented in the same order as the stacks in the bar chart.

Source: British Trust for Ornithology, Defra, Joint Nature Conservation Committee and the Royal Society for the Protections of Birds.

The farmland bird index contains data for 19 species. The long-term decline of the farmland bird indicator in England has been driven mainly by the decline of those species that are restricted to, or highly dependent on, farmland habitats (the ‘specialists’). Between 1970 and 2022, the index for farmland specialists declined by 75% while for farmland generalists it declined by 14% (Figure 5.3).

Figure 5.3: Trends for the abundance of specialist and generalist farmland birds in England, 1970 to 2022

Download the data for Figure 5.3 in ods format

Notes about figure 5.3

• This indicator includes individual measures for 19 species of farmland birds, of which 12 species are farmland specialists and 7 species are farmland generalists.
• Figure 5.3 shows the unsmoothed trends (dashed lines) and the smoothed trends (solid lines).

Source: British Trust for Ornithology, Defra, Joint Nature Conservation Committee and the Royal Society for the Protections of Birds.

Changes in farming practices, such as the loss of mixed farming systems, the move from spring to autumn sowing of cereal crops, and increased pesticide use, have been demonstrated to have had adverse impacts on farmland birds such as skylark and grey partridge. Five farmland specialists (corn bunting, grey partridge, starling, turtle dove and tree sparrow) have experienced severe declines, between 85 and 99%, since 1970. In contrast, numbers of two other farmland specialists (stock dove and goldfinch) have more than doubled over the same period, illustrating how responses to pressures varies among species.

Butterflies of the wider countryside on farmland

Trend description for Figures 5.4 and 5.5

The abundance of butterflies on farmland has remained largely unchanged from the start of 1990 (Figure 5.4). In the short term, since 2017, the abundance of butterflies has also shown little or no change.

Large fluctuations in numbers between years are typical features of butterfly populations, principally in response to weather conditions. Overall, 2022 was an average year for butterflies in England, with 46% of all species contributing to the England indicators (23 out of 50) falling in abundance from the previous year. 2022 was the warmest year on record, although the weather fluctuated considerably each month with cooler and unsettled periods alternating with warmer, more settled spells. The rainfall was mostly below average with drought conditions in second half of the summer, especially in eastern parts of England.

Figure 5.4: Trends for the abundance of butterflies of the wider countryside on farmland in England, 1990 to 2022

Download the data for Figure 5.4 in ods format

Figure 5.5: Long-term and short-term changes in individual species trends for butterflies of the wider countryside on farmland in England, 1990 to 2022

Download the data for Figure 5.5 in ods format

Notes about figures 5.4 and 5.5

• This indicator includes individual measures for 22 species of butterflies, the farmland index, however, only includes 21 trends. This is because an aggregate trend is used for small skipper (Thymelicus lineola) and Essex skipper (Thymelicus sylvestris); these 2 species have been combined due to historical difficulties with distinguishing between them in the field.
• Figure 5.5 shows the percentage of species trends within the indicator that have shown a statistically significant increase, a statistically significant decrease or no statistically significant change (little change).

Source: Butterfly Conservation, British Trust for Ornithology, Defra, Joint Nature Conservation Committee and the UK Centre for Ecology & Hydrology.

Individual butterfly species fare differently within the overall stable trend. Some species on farmland show a significant long-term decline including small tortoiseshell; wall; gatekeeper; large skipper; small copper and small or Essex skipper. Large skipper also decreased significantly on farmland over the short term (since 2017). Five species on farmland, brimstone; marbled white; the ringlet; speckled wood and white-letter hairstreak increased significantly over the long term, but no species of butterfly have increased significantly on farmland since 2017.

Widespread bats

Due to the COVID-19 pandemic, National Bat Monitoring Programme Hibernation Surveys were suspended during the winter of 20/21. As a result, the 2021 bat index value has been estimated using imputed Hibernation Survey data for that year.

The assessment of long and short-term change would usually be based on smoothed trends to the penultimate year, which in this case would be 2021. This is because the most recent smoothed data point (2022) is likely to change in next year’s update when additional data are included for 2023. However, due to the reliance of the 2021 index value on imputed data the assessments of change for the bat index are based on the penultimate year for which full data is available, which is 2020. The latest year change is assessed between 2020 and 2022 and is based on unsmoothed values.

Trend description for Figures 5.6 and 5.7

Since 1999, the England widespread bat index has increased by 43% (Figure 5.6). This is likely due in part to the introduction of strict legal protection for bats and a milder climate (Burns et al., 2016). In the short term, between 2017 and 2022, the smoothed bat index has increased by 5%. The bat species within this index vary in their habitat requirements, but all occur in farmland and woodland landscapes. For convenience, they are only presented here in the farmland indicator.

Figure 5.6: Trends in abundance of 11 widespread bat species in England, 1999 to 2022

Download the data for Figure 5.6 in ods format

Figure 5.7: Long-term and short-term changes in individual species trends for widespread bats in England, 1999 to 2020

Download the data for Figure 5.7 in ods format

Notes about figures 5.6 and 5.7:

• Figure 5.6 shows the unsmoothed trend (dashed line) and the smoothed trend (solid line) together with its 95% confidence interval (shaded area).
• This indicator includes 10 trends, comprising individual measures for 11 species of bats. An aggregate trend is used for whiskered bat and Brandt’s bat; these 2 species have been combined due to difficulties distinguishing between them in the field.
• Figure 5.7 shows the percentage of species groups within the indicator that have increased, decreased or shown little change.

Source: Bat Conservation Trust.

The long-term increase in the England bat index is primarily driven by large, statistically significant increases in the trends of greater horseshoe bat, lesser horseshoe bat and common pipistrelle. Between 1999 and 2020, the combined survey trend for these species increased by 216%, 113% and 85% respectively. One species showed a weaker increase over the same period, and the remaining 6 species groups showed no significant change.

In the short term, between 2015 and 2020, 2 species have increased significantly, and 8 species groups showed no significant change. No species showed a decline in either the long or short term, however it is not possible to produce separate trends for whiskered bat and Brandt’s bat as they cannot be reliably distinguished between in the field. It is therefore possible that an increase in one species could mask a decline in the other. It is also important to note that England’s rarer and more specialised bat species are not included in the index due to difficulties monitoring these species.

The bat index and long-term assessment reflect changes in bat populations since 1999. It is generally considered that prior to this there were major declines in bat populations throughout Western Europe during the 20th century.

Abundance of farmland plant species (Official Statistics in Development)

The Biodiversity Indicators project team would welcome feedback on the novel methods used in the development of this indicator.

Data collection for the National Plant Monitoring Scheme was severely affected by the COVID-19 pandemic. Due to this, the species abundance estimates for 2020 are likely to be biased and should be treated with caution.

This indicator measures, in small plots, change in the abundance of plant species considered indicative of good habitat condition on UK farmland, using modelled abundance data from the National Plant Monitoring Scheme (NPMS). Plant populations form the environment in which most other species exist, as well as providing numerous ecosystem services. Drivers of change are well-understood for many UK habitats.

Trend description for Figures 5.8 and 5.9

In 2022, average indicator plant abundance for the 2 broad farmland habitat types included within this UK indicator are above the 2015 level (Figures 5.8 and 5.9).

Arable field margins, while fluctuating annually, shows an overall increase of 14% between 2015 and 2022. Lowland grassland shows a decline followed by a gradual rise and is 9% higher than its 2015 level.

Figure 5.8: Trends for the abundance of plant species in UK arable field margins habitat type, 2015 to 2022

Download the data for Figure 5.8 in ods format

Figure 5.9: Trends for the abundance of plant species in UK lowland grassland habitat type, 2015 to 2022

Download the data for Figure 5.9 in ods format

Notes about Figures 5.8 and 5.9:

• Figures 5.8 and 5.9 show the unsmoothed trends (dashed lines); the variation around the lines shown (the shaded areas) is the standard deviation of 1,000 simulated trend indices calculated according to the method of Soldaat, L.L., Pannekoek J., Verweij, R.J.T., Van Turnhout, C.A.M. and Van Strien, A.J. (2017). A Monte Carlo method to account for sampling error in multi-species indicators. Ecological Indicators, 81: 340–347 doi:10.1016/j.ecolind.2017.05.033.
• abundance is measured by the percentage area covered by a species within a plot.
• the figures in brackets indicate the number of species or species aggregates included in the composite index for that particular habitat type.
• data collection for the National Plant Monitoring Scheme was severely affected by the COVID-19 pandemic, and the species abundance estimates for 2020 are likely to be biased and thus should be treated with caution.

Source: Botanical Society of Britain and Ireland, Joint Nature Conservation Committee, National Plant Monitoring Scheme, Plantlife and the UK Centre for Ecology & Hydrology.

The National Plant Monitoring Scheme (NPMS) was designed to monitor UK habitats of conservation importance. This is achieved through the establishment of small plots in areas of habitats targeted by the scheme. The abundances of plant species, measured as the percentage area covered by a species within a plot, are recorded each year. Surveyors record from different lists of indicator species depending on their level of experience and the habitat within which a plot is located. Both the placement of plots, and the selection of 1 kilometre national grid squares within which the plots are located, are subject to statistical methodologies designed to minimise bias (Pescott et al., 2019a).

The design of the NPMS included the definition of a set of 11 broad habitat types, within which 28 finer habitat types are nested. These fine-scale habitats are linked to existing classifications such as the British National Vegetation Classification. Surveyors can choose, based on their knowledge of a habitat, whether to record a plot at the broader or finer level. The current indicator summarises species’ percentage cover (abundance) data at the broad habitat level. This is done using a model that is able to account for both the range of percentage covers that a species may exhibit in a habitat when present, and the fact that species may often be absent from any given plot (Pescott et al., 2019b). Such data are often described as ‘zero-inflated’. This model is applied across years for each species and habitat combination, and the indicators presented here for each broad habitat are the result of combining the resulting species and habitat time trends across the relevant set of NPMS habitat indicator species.

The 2 broad UK farmland habitat measures presented in this indicator (arable field margins and lowland grassland) are a subset of those for which the largest numbers of NPMS plots currently exist. See the technical background document for more detail.

Further information

Relevance

Species groups such as bats, birds and butterflies are considered to provide a good indication of the broad state of the environment because they occupy a wide range of habitats and there are long-term data on changes in populations which help in the interpretation of shorter-term fluctuations.

Butterflies also respond rapidly to changes in environmental conditions and habitat management, are representative of many other insects, in that they utilise areas with abundant plant food resources and play a complementary role to birds and bats as an indicator, because they use the landscape at a far finer spatial scale.

Plants are a large part of the fundamental fabric of which habitats are made and directly indicate changes to environmental conditions and habitat management. Plants provide essential habitats and food for wildlife, and essential ecosystem services for humans, such as reduced erosion, nutrient cycling, oxygen production, and climate regulation.

These indicators show progress towards commitments to improve the status of our wildlife and habitats. They are relevant to outcomes 1 and 3 in Biodiversity 2020, A strategy for England’s wildlife and ecosystem services (see Annex A of the publication). The indicators are also relevant to international goals and targets (see Annex B of the aforementioned publication).

The UK and England Biodiversity Indicators are currently being assessed alongside the Environment Improvement Plan Targets, and the new Kunming-Montreal Global Biodiversity Framework Targets, when this work has been completed the references to Biodiversity 2020 and the Aichi Global Biodiversity Framework Targets will be updated.

Background

Breeding birds on farmland

The farmland bird measure has been supplied by the British Trust for Ornithology (BTO), the Royal Society for the Protection of Birds (RSPB) and JNCC and is compiled using data from the Common Bird Census (CBC) and Breeding Bird Survey (BBS). Within the farmland bird measure there are trends for 19 species (Table 5.1). Each species is given equal weighting and the index is the geometric mean of the individual species indices. The assessment of change is based on a statistical test of the underlying trend, using smoothed species trends derived from general additive models, with bootstrapping to generate confidence limits. Further details about species and methods can be found on the BTO website (see the Web links for further information section of this document).

Table 5.1: Species included in the farmland bird indicator

Common.name	Species.name	Category
greenfinch	Chloris chloris	Generalist
jackdaw	Corvus monedula	Generalist
kestrel	Falco tinnunculus	Generalist
reed bunting	Emberiza schoeniclus	Generalist
rook	Corvus frugilegus	Generalist
woodpigeon	Columba palumbus	Generalist
yellow wagtail	Motacilla flava	Generalist
corn bunting	Emberiza calandra	Specialist
goldfinch	Carduelis carduelis	Specialist
grey partridge	Perdix perdix	Specialist
lapwing	Vanellus vanellus	Specialist
linnet	Carduelis cannabina	Specialist
starling	Sturnus vulgaris	Specialist
stock dove	Columba oenas	Specialist
skylark	Alauda arvensis	Specialist
tree sparrow	Passer montanus	Specialist
turtle dove	Streptopelia turtur	Specialist
whitethroat	Sylvia communis	Specialist
yellowhammer	Emberiza citrinella	Specialist

Composite indicators can mask a lot of variation among the species within them. The bar chart provided alongside the headline chart (Figure 5.2), shows the percentage of species within the 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 an increase of 33% or below a decrease of 25% are labelled ‘weak’. Asymmetric thresholds are used for declines and increases to represent an equivalent 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.

Butterflies of the wider countryside on farmland

The farmland butterfly indicator is a composite (multi-species) index compiled by Butterfly Conservation (BC) and the UK Centre for Ecology & Hydrology (UKCEH) from data collated through the UK Butterfly Monitoring Scheme (UKBMS) including the Wider Countryside Butterfly Survey (WCBS). It uses butterfly count data collected at UKBMS butterfly transect sites on farmland together with additional data from randomly selected 1 km squares of the WCBS primarily comprised of farmland (totalling 3,497 sample locations across England), see the [UKBMS sites details map] (https://ukbms.org/sites) for further information.

The indicator includes 22 species of butterflies associated with farmland; however, the farmland measure only includes trends for 21 species because an aggregate trend is used for small skipper (Thymelicus lineola) and Essex skipper (Thymelicus sylvestris). These 2 species have been combined due to historical difficulties with distinguishing between them in the field (see Table 5.2).

Table 5.2: Species included in the England farmland butterfly indicator

Common.name	Species.name
brimstone	Gonepteryx rhamni
brown argus	Aricia agestis
common blue	Polyommatus icarus
gatekeeper	Pyronia tithonus
green-veined white	Pieris napi
holly blue	Celastrina argiolus
large skipper	Ochlodes venata
large white	Pieris brassicae
marbled white	Melannargia galathea
meadow brown	Maniola jurtina
orange-tip	Anthocharis cardamines
peacock	Aglais io
ringlet	Aphantopus hyperantus
small copper	Lycaena phlaeas
small heath	Coenonympha pamphilus
small tortoiseshell	Aglais urticae
small/Essex skipper	Thymelicus sylvestris/lineola
small white	Pieris rapae
speckled wood	Pararge aegeria
wall	Lasiommata megera
white-letter hairstreak	Satyrium w-album

The year-to-year fluctuations in butterfly numbers are often linked to natural environmental variation, especially weather conditions. Therefore, in order to identify underlying patterns in population trends, the assessment of change is based on smoothed indices. The smoothed trend in the composite indicator is assessed by structural time-series analysis. A statistical test is used to compare the difference in the smoothed index in the latest year versus other years in the series. Within the measures, each species is given equal weight, and the annual figure is the geometric mean of the component species indices for that year.

Populations of individual species within the measure may be increasing or decreasing irrespective of the overall trends. The bar chart provided alongside the headline trend chart (Figure 5.5), shows the percentage of species within the indicator that have shown a statistically significant increase, a statistically significant decrease or shown no statistically significant change (little change). A table summarising the estimated long-term and short-term changes for each species together with an assessment of the individual species trends can be found in the statistical data set trends in populations of selected butterfly species.

As there are delays in data submission, data for previous years are also updated retrospectively. This means that the species indices for individual years may vary from previous publications.

Further details of the methods used can be found on the UKBMS website and in the Technical background document for this indicator.

Widespread bats

The England bat index is produced by the Bat Conservation Trust using data collected annually from the National Bat Monitoring Programme (NBMP). The NBMP has deployed 4,152 survey volunteers (3,080 in England) to record bat population data at 7,101 survey sites (4,959 in England). Surveys of bat species include summer roost counts, counts at hibernation sites and visual and/or acoustic observations made along predetermined transects.

Most species are surveyed by 2 different methods, both of which are included in the index apart from summer roost count data for common and soprano pipistrelle. Frequent ‘roost switching’ by these 2 species of bats can cause a negative bias in trends calculated from summer roost counts, so these data are omitted (Dambly et al, 2021). In 2018, 3 additional species were added to this indicator; the entire time series in the accompanying dataset was updated to reflect these changes.

The farmland bat index includes 10 trends covering 11 of the 17 species of breeding bats present in England. An aggregate trend is used for whiskered bat and Brandt’s bat; these 2 species have been combined due to difficulties distinguishing between them in the field (Table 5.3).

Table 5.3: Species included in the bat indicator

Common.name	Species.name
Daubenton’s bat	Myotis daubentonii
Natterer’s bat	Myotis nattereri
whiskered/Brandt’s bat	Myotis mystacinus/Myotis brandtii
lesser horseshoe bat	Rhinolophus hipposideros
greater horseshoe bat	Rhinolophus ferrumequinum
noctule	Nyctalus noctula
serotine	Eptesicus serotinus
common pipistrelle	Pipistrellus pipistrellus
soprano pipistrelle	Pipistrellus pygmaeus
brown long-eared bat	Plecotus auritus

For each bat species included in the index, Generalised Additive Modelling (GAM) is used to calculate the trends in numbers over time (Fewster et al., 2000). The models include terms for factors that can influence the apparent population means (for example, the bat detector model and temperature), so their effect can be taken into account. The GAM models produce smoothed trends which are more robust against random variation between years. For easier interpretation the means are then converted to an index that is set to 100 for the selected baseline year of data.

The species indices are revised when new data become available or when improved modelling methods are developed and new methods are applied retrospectively to data from earlier years. As such, indices published in previous years are not strictly comparable to the current index.

To generate the composite bat indicator and confidence intervals, each species has been given equal weighting, and the annual index figure is the geometric mean in that year (Figure 5.3). Confidence intervals are relatively wide due to the high variability inherent in bat monitoring data and the rarity of several species.

Long and short-term assessments are run to the penultimate year of the trend as the most recent year’s smoothed data point is likely to change as future years of data are added. The latest-year change is therefore based on unsmoothed data. The survey methods and statistical analysis used by the NBMP to produce individual species trends are described in Barlow et al. (2015).

Bat populations are believed to have undergone major declines throughout Western Europe during the 20th century, which have been attributed to persecution, agricultural intensification, habitat and roost loss, remedial timber treatment and declines of their insect prey. Evidence of these declines (synthesised in Haysom et al., 2010) is fragmented as during this period few data were collected in a systematic way. Evidence includes:

• well documented range contractions of greater horseshoe bat and lesser horseshoe bat across Great Britain and Europe
• reports of the loss of large colonies of several species from traditional roosting sites
• reductions in the number of known maternity colonies across Great Britain
• a small number of published population trends (for example, Ransome, 1989 and Guest et al., 2002)

The bat index suggests that more recently some English bat populations are beginning to recover. The greatest weight of evidence suggests two factors have had a positive impact on bat populations in the UK; a reduction in human disturbance since the introduction of strict legal protection, and a milder climate (Burns et al., 2016). Climate changes over winter and spring have been shown to benefit horseshoe bat species (Battersby, 2005; Froidevaux et al., 2017; Schofield, 2008). The impact of climate change on other English bat species is less clear.

Bats have also benefited from direct conservation action and public education (Mitchell-Jones 1993; Haysom et al., 2010), but remain vulnerable to pressures such as landscape change, climate change, development, wind turbines, and light pollution (Browning et al., 2021; Haysom et al., 2010; Kunz et al., 2007; Rebelo et al., 2010; Stone et al., 2009, 2012).

Abundance of farmland plant species

The creation of the NPMS allowed for the creation of annual trends in the abundance of plants in habitats of conservation importance. Following 5 years of development, the scheme was launched by a partnership consisting of the Botanical Society of Britain and Ireland (BSBI), JNCC, Plantlife, and UKCEH in 2015. This indicator uses a subset of the species selected by the NPMS as indicative of good condition in those habitat types considered to be of most importance for the conservation of UK biodiversity, see the see the technical background document for a full list of species included. These species are monitored in small sample plots (between 25 and 100 square metres in area) according to a methodology that was designed to minimise biases in data collection. Results for the UK arable field margins and lowland grassland habitats are presented here in the farmland plant species abundance indicator.

Since 2018, UKCEH, with input from all partners, have been developing a method of using NPMS data to indicate annual changes in habitat condition. The method is based on a hierarchical model, formulated in a Bayesian framework, that integrates information on a species’ abundance and occupancy. The occupancy estimates also take advantage of the fact that most plots are surveyed twice a year, allowing adjustments for false negatives (that is, species that are overlooked during surveys). Simulation tests and applications to real data indicate that the method is robust and produces ecologically sensible metrics. The 1 kilometre squares of the NPMS were selected according to a weighted-random algorithm designed to introduce a known bias towards semi-natural habitats. However, within this design, a sampling bias exists in that, in common with other UK structured monitoring schemes based on volunteer participation, squares located within lowland areas are more likely to be sampled. Further work will focus on additional adjustment for bias (Pescott et al., 2019b).

Until 2013, this indicator was based on analysis of the change in plant species richness in the wider countryside. Data were taken from the UK Countryside Survey. This survey provides a random sample of vegetation plots located in arable and horticultural fields, agricultural grasslands, woodlands and associated boundary habitats in Great Britain. Although now archived, the indicator can be viewed in full on the archived version of the JNCC website.

Web links for further information

• Bat Conservation Trust: The National Bat Monitoring Programme
• Botanical Society of Britain & Ireland: Home page
• British Trust for Ornithology: Breeding Bird Survey - Methodology and survey design
• British Trust for Ornithology: Potential volunteering for surveys
• British Trust for Ornithology: Publications - Bird Trends
• British Trust for Ornithology, Royal Society for the Protection of Birds and Defra: Technical background document - birds
• Butterfly Conservation: The state of Britain’s butterflies
• Butterfly Conservation and UK Centre for Ecology & Hydrology: [Technical background document - butterflies]
• Countryside Survey Home page
• Defra: Butterflies in England: species of the wider countryside on farmland and in woodland
• Defra: Wild bird populations in England
• Defra: Technical background document - butterflies
• Defra and UK Centre for Ecology & Hydrology: Technical background document - plants
• Joint Nature Conservation Committee: Tracking Mammals Partnership
• Joint Nature Conservation Committee: Home page
• National Plant Monitoring Scheme: Home page
• Plantlife: Home page
• UK Butterfly Monitoring Scheme: Butterflies as indicators
• UK Centre for Ecology & Hydrology: Home page

References

• Barlow, K. E., Briggs, P. A., Haysom, K. A., Hutson, A. M., Lechiara, N. L., Racey, P. A., Walsh, A. L. and Langton, S. D. (2015). Citizen science reveals trends in bat populations: the National Bat Monitoring Programme in Great Britain. Biological Conservation, 182, pp. 14 to 26.
• Battersby, J. (2005). UK Mammals: Species Status and Population Trends. First Report by the Tracking Mammals Partnership. Peterborough, UK.
• Browning, E., Barlow, K.E., Burns, F., Hawkins, C., Boughey, K. (2021), Drivers of European bat population change: a review reveals evidence gaps. Mammal Review, 51, pp. 353 to 368.
• Burns F, Eaton M. A., Barlow K. E., Beckmann B. C., Brereton T., Brooks D. R., Brown P. M. J., Al Fulaij A., Gent T., Henderson I., Noble D. G., Parsons M., Powney G. D., Gregory R. D. (2016) Agricultural Management and Climatic Change Are the Major Drivers of Biodiversity Change in the UK. PLoS ONE 11(3): e0151595. https://doi.org/10.1371/journal.pone.0151595.
• Dambly, L.I., Jones, K.E., Boughey, K.L., Isaac, N.J.B. (2021). Observer retention, site selection and population dynamics interact to bias abundance trends in bats. Journal of Applied Ecology, 58, pp. 236 to 247.
• 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.
• Froidevaux J. S. P., Boughey K. L., Barlow K. E., Jones G. (2017). Factors driving population recovery of the greater horseshoe bat (Rhinolophus ferrumequinum) in the UK: implications for conservation. Biodiversity and Conservation, 26, pp. 1 to 21.
• Guest, P., Jones, K. E. and Tovey, J. (2002). Bats in Greater London: unique evidence of a decline over 15 years. British Wildlife, 13, pp. 1 to 5.
• Harris, S., Morris, P., Wray, S. and Yalden, D. (1995). A review of British mammals: population estimates and conservation status of British mammals other than cetaceans. Peterborough, JNCC.
• Haysom, K. A., Jones, G., Merrett, D. and Racey, P. A. (2010). Bats. pp. 259 to 280 in: Maclean N (ed.) Silent Summer: The State of Wildlife in Britain and Ireland. Cambridge University Press.
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