Defra’s report says that the combined all-species index has changed little in 45 years
But its statistics show that, overall, farmland birds, woodland birds, seabirds and breeding waders have all declined
December 15th 2017
There are winners and losers in the latest set of Government statistics on the UK’s wild bird populations, with some species experiencing a large long-term increase and some a dramatic decline. For example, the numbers of wood pigeon, collared dove, jackdaw, magpie, goldfinch, nuthatch, long-tailed tit, green woodpecker, great spotted wood pecker, blackcap, black-headed gull, mute swan, buzzard and red kite have all increased in the last 45 years, whereas the numbers of lapwing, curlew, redshank, snipe, turtle dove, tree sparrow, house sparrow, greenfinch, song thrush, skylark, starling, willow tit, marsh tit, yellow wagtail, cuckoo, swift, herring gull and lesser spotted woodpecker have all declined.
The statistics were published by the Department for the Environment, Food and Rural Affairs (Defra) last month. These figures are gathered annually by Defra from a wide variety of sources, working in conjunction with the RSPB, the British Trust for Ornithology (BTO), and the Joint Nature Conservation Committee (JNCC). The sources include the Breeding Bird Survey, the Waterways Bird Survey, the Wetland Bird Survey, the Seabird Monitoring Programme, the Goose and Swan Monitoring Programme, and the Common Birds Census. These national surveys and monitoring programmes are carried out largely by volunteer experts at representative sites which are resurveyed regularly on an annual basis. Defra says it is impractical to determine changes in the actual numbers of birds for each species in the UK each year, but it is possible and also more reliable to assess their status by calculating relative change, based on counts at these representative sample plots. On the rationale for compiling the statistics, Defra says:
“Bird populations have long been considered to provide a good indication of the broad state of wildlife in the UK. 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 the short term and long term.” 
Defra says it uses the data as indicators to show whether the environment is being managed sustainably: “Trends in bird populations are used by policy makers, government agencies and non-governmental organisations as part of the evidence base to assess the effects of environmental management, such as agricultural practices, on bird populations. The trends are also used to assess the effectiveness of environmental interventions intended to address declines, such as agri-environment schemes targeted at farmland birds.” However, Defra says the indicators presented in its report are not intended to be seen in isolation as indicators of the health of the wider natural environment.
The ‘all-species index’ of 130 common birds shows a long-term decline of 8%
Defra’s ‘National Statistics Release’ includes data on 130 species of common birds, defined as species with populations of at least 500 breeding pairs that are native to (and breed in) the UK. The latest report presents data trends up to 2016 and shows overall trends as well as trends for four main habitat groups: farmland birds, woodland birds, wetland birds, and marine birds. The statistical analysis and indicators exclude rare species (species with less than 500 breeding pairs) and all species for which no UK trend information is available. Of the 130 species, 16 are included in the farmland bird index, 37 in the woodland bird index, 23 in the water and wetlands bird index, 13 in the seabird index, and 3 are included in both the farmland and the wetland bird index (yellow wagtail, reed bunting and lapwing, due to their reliance on both of these habitats). The ‘all-species index also includes 38 species from other habitats (urban areas, heathland, upland and coastal areas) together with species that have no strong habitat preferences (known as ‘generalists’). Additionally, the latest report presents trends for wintering waterbirds, some of which also breed in the UK and some of which are included in the all-species index.
To monitor changes in bird populations, Defra calculates trends in individual species as a series of annual indices. These annual indices relate the population in a given year to 1970, the first year for which data is available. The year 1970 is then used as a baseline and given the value of 100. Thereafter, the individual bird species index expresses the population as a percentage of this baseline. In summary, Defra says that the combined all-species index has changed little compared to that of 45 years ago, but the overall picture masks considerable flux, with some species increasing and some species decreasing. In fact, Defra’s statistics show an overall decline of 8% in the 45-year period from 1970 to 2015. In the short term (the five-year period from 2010 to 2015), the figures show a smaller decline of 1%. 
In terms of habitats, farmland birds have suffered the worst decline at 56% over the 1970 to 2015 period, meaning numbers are now less than a half of what they were 45 years ago. Their numbers have continued to decline in the short term, with a 9% fall in the five-year period 2010 to 2015. Woodland birds have also declined, with a 23% fall in the 1970 to 2015 period and a 2% fall in the 2010 to 2015 period. Seabirds have suffered a similar rate of decline, though the time span covers a shorter period. Seabird numbers fell by 20% in the period 1986 to 2014 and by 6% in the five-year period 2009 to 2014. Wetland birds have fared better, with no significant change in the 1975 to 2015 period and just a 2% fall in the 2010 to 2015 period. The numbers of declining species are counterbalanced by a rise in the numbers of wintering waterbirds, which have seen a 92% increase in the period 1975/76 to 2014/15 but have fallen by 8% more recently in the five-year period 2009/10 to 2014/15. We now look at these changes in more detail, beginning with farmland birds. 
Land use in the UK
How much of the UK’s land area is devoted to agriculture? A detailed picture of land use in the UK has now been made available to the public, thanks to research by the BBC with the help of Dr Alasdair Rae from the Urban Studies and Planning Department at the University of Sheffield. The data is derived from an ongoing project on changing land use known as ‘Corine’ (Coordination of Information on the Environment), initiated by the European Commission in 1985 and now taken over by the European Environment Agency. Since that time, satellites have been taking high definition images of land in the EU, including the UK, which are then analysed and compared to detailed maps. The Corine project uses 44 different codes to categorise land use and to track and measure changes, such as increases or decreases in woodland cover. The Corine project has made this data publicly accessible, and the BBC has analysed the data for the UK to present a simplified picture of land use. BBC Home Correspondent Mark Easton says: “To get a clearer idea of how UK land is used, we have divided the 44 different land use types into four broad categories: farmland (pastures, arable land, orchards, vineyards etc.); natural (moors, forests, lakes, grasslands etc.); built on (buildings, roads, airports, quarries etc.); and green urban (parks, gardens, golf courses, football pitches etc.)” 
England has the highest percentage of farmland in the UK at 72.9%
For the UK as a whole, the data shows that more than half of the UK land area (56.7%) is devoted to agriculture, and just over a third (34.9%) could be classed as ‘natural’. The ‘green urban’ category comprises 2.5% and the ‘built on’ category comprises 5.9%. Mark Easton says the categories will always be open to debate because, for instance, moorland used by sheep farmers could be placed in either ‘agriculture’ or ‘natural’. The research team opted to put moorland into the ‘natural” category. 
The picture varies across the UK however. England has the highest percentage of farmland at 72.9%, with Northern Ireland a close second at 72.2%. In Wales, farmland comprises 59.3%, and in Scotland only a quarter (26.4%) is classed as farmland. With regard to the ‘natural’ category, Scotland comes out on top at 70.7%, Wales second at 35.1%. Northern Ireland third at 23%, and England last at 14.5%. England has the highest percentage of ‘built on’ land at 8.8% but also the highest percentage of ‘green urban’ at 3.8%. Wales has the second highest percentage of ‘built on’ land at 4.2%.
Farmland bird populations have declined by 56% since 1970
As detailed above, farmland covers more than a half (56.7%) of the UK’s land area. In England and Northern Ireland, the percentage is higher at 72.9% and 72.2% respectively, and in Wales the percentage is 59.3%. In its report, Defra says that farmland provides semi-natural habitats for birds, such as hedgerows and field margins that provide food and shelter. In 2016 the UK farmland bird index, covering 19 species, was less than a half of its 1970 value (a 56% decline). Defra says the majority of this decline occurred between the late 1970s and the 1980s, largely due to the impact of rapid changes in farmland management during this period:
“For a large part, declines have been caused by the changes in farming practices that have taken place since the 1950s and 1960s, such as the loss of mixed farming, a move from spring to autumn sowing of arable crops, changes in grassland management (a switch from hay to silage production, for example), increased pesticide and fertiliser use, and the removal of non-cropped features such as hedgerows. The rate of these changes, which resulted in the loss of suitable nesting and suitable feeding habitats, and a reduction in available food, was greatest during the late 1970s and early 1980s, the period during which many farmland bird populations declined most rapidly.”
The 19 species that are included in the farmland bird index fall into two categories: specialists and generalists. The farmland specialists are those species that are restricted to, or are highly dependent on, farmland habitats. The 12 specialists are the corn bunting, goldfinch, grey partridge, lapwing, linnet, skylark, starling, stock dove, tree sparrow, turtle dove, whitethroat and yellowhammer – the lapwing is also included in the wetland bird index. Five farmland specialists have experienced declines of 80% or more since 1970: turtle dove by 98%; grey partridge by 92%, tree sparrow by 90%; corn bunting by 90%; and starling by 81%. Another four have declined by 50% or more: lapwing by 64%; skylark by 59%; yellowhammer by 56%; and linnet by 55%. Whitethroat numbers have declined by 6%. In contrast, two farmland specialists have experienced a strong increase over the same period: goldfinch by 159% and stock dove by 113% . Between 2010 and 2015, farmland specialists declined overall by 10%, but the report says that a number of species have shown a marked change over this five-year period, with turtle dove decreasing by 71%, lapwing by 17%, and grey partridge by 15%, whereas stock dove and goldfinch increased by 17% and 15% respectively. Although tree sparrow numbers have declined in the long term, the short-term trend shows a weak increase of 8%.
Farmland generalists have fared better than the specialists
The farmland generalists are those species that are not restricted to farmland habitats. The 7 species of generalists included in the farmland bird index are the greenfinch, jackdaw, kestrel, reed bunting, rook, wood pigeon, and yellow wagtail – the reed bunting and yellow wagtail are also included in the wetland bird index. While changes in farming practices, such as sowing cereal crops in the autumn instead of the spring, are known to have adversely impacted farmland specialists such as skylark and grey partridge, generalist species such as wood pigeon have benefited from the increased availability of food throughout the winter. Of the seven generalists, the figures show that four have declined over the long-term period: yellow wagtail by 68%, kestrel by 50%; greenfinch by 46%; and reed bunting by 30%. The rook population has not changed significantly (a 7% increase), while wood pigeon and jackdaw populations have experienced a strong increase relative to 1970 levels: wood pigeon by 122% and jackdaw by 148%. As for the most recent short-term data, the statistics show that the greenfinch population has continued to decline in the five-year period from 2010 to 2015, with the figures showing a fall of 40%, while yellow wagtail, in contrast to the long-term trend, saw a rise of 18%.
Defra says the long-term decline of farmland birds in the UK has been driven mainly by the decline of the specialists, as they have suffered the greatest impact from the historical changes in farming practices. Comparing the generalists and the specialists over the 45-year period from 1970 to 2015, the statistics show a decline of 70% for specialists and 13% for generalists.
In moves to halt this decline, Defra says a number of incentive schemes now in place encourage improved environmental stewardship in farming, with some measures specifically designed to help stabilise and recover farmland bird populations. These include the provision of over-wintered stubble, planting wild bird crops to provide seed in the winter, not cropping the margins of arable fields, and the sympathetic management of hedgerows.
Turtle Dove: Threatened with extinction
Some of these schemes are targeted at specific species. For example, the decline of the turtle dove was recently highlighted when the International Union for the Conservation of Nature (IUCN) added the turtle dove to its Red List list of bird species threatened with extinction.  Turtle doves are migratory birds that spend less than half a year in the UK but come here to breed, primarily in the east and south-east of England. Changes in arable farming practice have had an impact on their habitat and food supply and have been cited as the main reason for their decline.  Farmers and landowners in the east of England have subsequently taken up their cause via the Countryside Stewardship scheme, creating feeding habitat for the birds and allowing their food plants to return to the arable landscape. In another example, the RSPB has been working on a collaborative project with the cement manufacturer CEMEX to provide habitats for the turtle dove in Warwickshire and the twite in Derbyshire. The company is managing hay meadows and creating conditions that will allow plant species more usually associated with arable land to flourish, which will provide seeds for the birds to feed on at critical times of the year. 
Woodland birds have declined by 23% since 1970
Last year, the Forestry Commission published a national inventory of the UK’s woodlands, which estimated the changes in woodland and canopy cover between 2006 and 2015.  It calculates that 13% of the UK’s land area is covered by woodland, a figure repeated in Defra’s report. Woodland birds included in the index have suffered a 23% decline overall during the 1970 to 2015 period and a 2% fall in the short-term (2010 to 2015). Defra says the greatest decline occurred between the early 1980s and the early 1990s. Since 1995, the index has been more stable at around 80% of the 1970 count. However, Defra says the relatively stable trend for all woodland birds from the mid-1990s masks different underlying trends for specialist species (those that are highly dependent on woodland habitats) and generalist species, which are found in a wide range of habitats including woodland. In 2016, the woodland specialists index was 41% lower than in 1970, whereas for woodland generalists it was 6% higher.
As for the reasons for the decline, Defra says there are several known and potential causes, “such as a lack of woodland management and increased deer browsing pressure,” both of which have resulted in a reduction in the diversity of woodland structure and the availability of suitable nesting and foraging habitats. The report adds that several declining woodland birds are long-distance migrants, “and a decline in the extent or quality of habitats used outside the breeding season may be one factor affecting these species outside of the UK.”
The loss of ancient woodlands
However, there is another reason for the decline of woodland birds which the report fails to mention, and that is the pressure from development. The loss of woodland habitat is bound to have an impact on the birds and wildlife that depend on it, particularly on the specialists who find it difficult or impossible to adapt. The Woodland Trust says that the UK’s richest habitat for wildlife is ancient woodland, which is at least 400 years old and covers just 2% of the UK. But it warns that these ancient woods are threatened by infrastructure projects and developments such as new roads, rail expansions, housing schemes and urban sprawl. In particular, phase two of the HS2 rail project which would link Birmingham, Manchester and Leeds to London would also result in the destruction of 20 ancient woodlands and indirect damage to another 15. The Woodland Trust says that “our natural crown jewels,” such as Whitmore Wood near Newcastle-under-Lyme, could be lost forever. “Currently, 98 ancient woods are threatened with loss or damage from both Phase 1 and Phase 2 of the project,” it says. 
Blackcap and nuthatch populations have more than doubled since 1970
Looking back rather than forwards, however, the figures for woodland birds present a mixed picture. The woodland bird index contains data for 37 species, of which 25 are listed as woodland specialists and 12 as generalists. The 25 woodland specialists are the goldcrest, siskin, coal tit, marsh tit, willow tit, wood warbler, willow warbler, garden warbler, nightingale, blackcap, chiffchaff, great spotted woodpecker, lesser spotted woodpecker, green woodpecker, nuthatch, treecreeper, tree pipit, redstart, lesser redpoll, spotted flycatcher, pied flycatcher, jay, sparrowhawk, common crossbill, and capercaillie.
The figures show that six woodland specialists have declined by 75% or more relative to 1970 levels: willow tit by 93%, capercaillie by 89%; lesser redpoll by 87%, spotted flycatcher by 85%, lesser spotted woodpecker by 83%; and marsh tit by 75%. A further five have declined by 40% or more: tree pipit by 69%; wood warbler by 56%; nightingale by 48%; willow warbler by 44%; and pied flycatcher by 40%. And a further four have experience a smaller decline: goldcrest by 15%; common crossbill by 15%; treecreeper by 10%; and garden warbler by 10%. In contrast, populations of blackcap and nuthatch have more than doubled over the same period (blackcap by 288% and nuthatch by 250%), while the great spotted woodpecker has more than trebled with a 350% increase. A further seven specialists have also experienced a long-term increase (1970 to 2015): chiffchaff by 105%; green woodpecker by 100%; sparrowhawk by 83%; redstart by 66%; siskin by 54%; coal tit by 15%; and jay by 9%.
Looking at the more recent short term, the report says that a number of woodland specialists have shown marked trends in the five-year period from 2010 to 2015, with lesser spotted woodpecker decreasing by 38% and the common crossbill by 46%, whereas spotted flycatcher has increased by 25%, blackcap has increased by 21%, redstart, pied flycatcher and chiffchaff have all increased by 20%, and the tree pipit by 15%. A number of the specialists are summer migrants (such as willow warbler, garden warbler and chiffchaff), and Defra says trends in these long-distance migrants may reflect changing conditions at their wintering grounds, whereas declines in residents (such as lesser spotted woodpecker, willow tit and capercaillie) are due to changes at their breeding grounds.
Song thrush numbers have halved since 1970, but long-tailed tit has almost doubled
The 12 woodland generalists listed in the all-species index are the blackbird, robin, wren, song thrush, dunnock, blue tit, great tit, long-tailed tit, chaffinch, bullfinch, lesser whitethroat and tawny owl. Defra says most of these birds have adapted to using gardens and wooded areas in farmland landscapes, and the majority have not shown a substantial change over the long term period from 1970 to 2015. However, populations of five woodland generalists have declined since 1970: song thrush by 50%; bullfinch by 39%; tawny owl by 37%; dunnock by 29%; and blackbird by 16%. In contrast, populations of seven woodland generalists have increased since 1970: long-tailed tit by 97%; great tit by 80%; wren by 67%; robin by 55%; lesser whitethroat by 23%; blue tit by 21%; and chaffinch by 21%.
Looking at the recent short-term period of 2010 to 2015, Defra reports a 2% increase overall for the woodland generalists. However, 4 of the 12 have decreased in this five-year period while 4 of the 12 have increased. The short-term trends also show a reversal of the long-term trends for six of the woodland generalists. In contrast to a long-term increase, the numbers of chaffinch decreased in this short-term period by 12%, long-tailed tit decreased by 7%, great tit by 6%, and blue tit also by 6%. And in another reversal, song thrush numbers were up by 9% and bullfinch by 8%, in contrast to a long-term decline. Meanwhile, wren numbers increased by 31% and robin by 12%, reflecting long-term trends for both species.
Water and Wetland Birds
The water and wetland bird index contains data for 26 species. Defra’s category of water and wetlands includes a range of habitats: rivers, lakes, ponds, reed beds, coastal marshes and lowland raised bogs. According to the report, these habitats totalled together represent 3% of the UK’s land area. Defra divides this total into four sub-habitats for producing indicators: slow flowing and standing water; fast flowing water; reed beds; and wet grassland. The statistics show that, overall, the wetland bird index has experienced no significant change in the 1975 to 2015 period, and just a 2% fall in the 2010 to 2015 period. However, Defra says this relatively stable trend masks underlying differences between sub-habitat indicators. The species included in the sub-habitats are as follows:
- Slow flowing and standing water (six species): mallard, coot, moorhen, tufted duck, little grebe, great crested grebe
- Fast flowing water (four species): common sandpiper, dipper, goosander, grey wagtail
- Reed beds (four species): Cetti’s warbler, reed bunting, reed warbler, sedge warbler
- Wet grassland (eight species): curlew, lapwing, redshank, snipe, little egret, mute swan, teal, yellow wagtail
- Other (four species): sand martin, kingfisher, grey heron, oystercatcher
Defra says the four species in the ‘other’ category do not show a strong preference for any of the sub-habitats, “either being fairly generalist or with large proportions of their populations in other habitats such as coasts (e.g. oystercatcher).”
Sharp declines in yellow wagtail and breeding waders
The statistics show a wide variation in the changes to the populations of the 26 species, with some species increasing dramatically over a 40-year period while some have declined strongly. The changes for the five groupings are as follows (unless stated otherwise, the time span is the 1975 to 2015 period):
- Slow flowing and standing water: the mallard population has increased by 213%, tufted duck by 99%, and coot by 69%, but the moorhen population has declined by 30%, little grebe by 27%, and great crested grebe (1995 to 2015) by 8%
- Fast flowing water: the goosander population has increased by 122% (1981 to 2015), while the other three species have declined (common sandpiper by 46%, grey wagtail by 39%, and dipper by 22%)
- Reed beds: the Cetti’s warbler population has increased by 632% (1989 to 2015) and reed warbler by 83% (1981 to 2015), but the reed bunting population has declined by 63% and sedge warbler by 42%
- Wet grassland: the yellow wagtail population has declined by 97%, snipe by 81%, redshank by 55%, lapwing (1980 to 2015) by 52%, and curlew (1980 to 2015) by 19%, but the mute swan population has increased by 86% and teal by 75% (1995 to 2015) – there are no long-term statistics for the little egret as this is a later addition to the index, first included in 2006
- Other: the oystercatcher population has increased by 66% and sand martin by 7% (1978 to 2015), but the kingfisher population has declined by 19% and grey heron by 17%
The report says that birds of slow flowing and standing water have shown the most positive trend, as shown by the above figures, with marked increases in mallard and tufted duck and a smaller increase in coot. However, Defra also says these trends should be interpreted with caution as each sub-habitat trend is derived from relatively few species. As for negative trends, the birds of wet grasslands have seen the most dramatic declines. Defra says the historical decline in breeding waders (such as lapwing, curlew, redshank and snipe) has resulted from land management changes, which have included drainage developments, the intensification of grassland management, and the conversion of coastal and floodplain grazing marshes to arable land. In addition: “Where populations persist in small fragments of high quality habitat, their nests and young can be vulnerable to predation, which is currently thought to be limiting the recovery of several species of breeding wader.”
According to Defra, the majority of the decline occurred between the peak in the mid-1980s and the mid-1990s. However, the statistics for the most recent short-term period show that curlew and lapwing numbers continue to decline, with an 11% fall in the lapwing population and a 3% fall in curlew numbers in the five-year period from 2010 to 2015. Yellow wagtail numbers have continued to fall even more dramatically, with a 53% drop in the same five-year period; this is a contrary trend to the figures for farmland specialists above, which show an 18% rise in yellow wagtail over the same period, though the long-term figures for both habitats show a decline (a 68% fall in the farmland index compared with a 97% fall in the wetland index).
Seabird numbers continue to decline
Defra’s all-species index contains data on 13 seabirds. Its report on their populations covers the 1986 to 2014 period. The data is sourced from the Seabird Monitoring Programme which has been collecting data on seabirds since 1986, but Defra says publication of the programme’s annual report was deferred for two years in 2016 in order to give priority to the breeding seabird census, Seabirds Count. Consequently, data for 2016 is not yet available. Presenting an overall picture, Defra says:
“The UK coast is over 30,000km long and consists of a wide variety of habitats, such as sea cliffs, sand dunes, shingle ridges, machair and intertidal areas. Additionally, the area of sea around the UK amounts to three and a half times the land area of the UK (not including overseas territories). In 2015, the breeding seabird index in the UK was 22% lower than in 1986, above the lowest level ever recorded in 2013 (27% lower than in 1986). Despite fluctuations the indicator was largely flat from 1986 until the mid-2000s when seabird numbers started to decline, falling 6% between 2009 and 2014.” 
The 13 seabirds in the index are as follows: Arctic skua; Northern fulmar; black-legged kittiwake; herring gull; great black-backed gull; razorbill; common guillemot; European shag; great cormorant; Arctic tern; sandwich tern; common tern; and little tern.
Report suggests predators and climate change as possible causes of seabird decline
The statistics show that five of the 13 seabird species in the index have increased since the beginning of the index in 1986: razorbill by 58%; common guillemot by 57%; Arctic tern by 39%; sandwich tern by 5%; and great black-backed gull by 7%. However, three species have experienced a marked decline: Arctic skua by 80%, black-legged kittiwake by 62%, and the European shag by 48%. The remaining five have also declined but not as sharply: common tern by 30%; Northern fulmar by 22%; herring gull by 16%; little tern by 12%; and the great cormorant by 7%. On the causes of these declines, Defra says some seabirds have been impacted through predation by invasive non-native mammals such as rats and mink, “though successful eradication programmes have been implemented in a number of areas and populations of some species have undergone local recoveries as a result.” The decline of black-legged kittiwakes, however, has been linked to rising sea temperatures as they tend to feed on the sea surface, but Defra says there has been some lessening of the rate of decline in the short term, “showing a weak rather than strong decline of 13% between 2009 and 2014.”
Looking at the short-term picture (the five-year period from 2009 to 2014), the figures show that herring gull and great black-backed gull populations have increased by 47% and 28% respectively, although the trends for these species show no change over the long term. However, Arctic skua numbers continue to decline sharply, with a 56% fall in the same five-year period. The report also highlights a difference in the seabird index for the UK as a whole and the index for England. Defra says one reason for this is species composition: “Some species breed only in Scotland whereas others are more widespread but have the bulk of their populations in northern parts of the British Isles, and there may be insufficient data to generate an England-only trend. In addition, trends for some species may differ between the two countries.”
The ‘Other’ Group: The collared dove has increased eight-fold in 45 years
The all-species bird index includes data on 38 species from other habitats (urban areas, heathland, upland and coastal areas) and species that have no particular habitat preferences (‘generalists’). The ‘other’ category includes six species of duck and geese (gadwall, greylag goose, pochard, red-breasted merganser, shelduck and shoveler) and five birds of prey (hen harrier, peregrine falcon, hobby, buzzard and red kite). Four species in the duck and geese group have all seen large increases in their populations over the 1970 to 2015 period, with red-breasted merganser up by 500%, greylag goose up by 298%, gadwall up by 126%, and pochard up by 44%. There is no long-term data for the shoveler while the shelduck population has seen an 8% decline over the same period. Three birds of prey have also seen large increases over the 45-year period: buzzard up by 465%, red kite up by 349%, and peregrine falcon up by 203%. The hobby population has experienced an 11% decrease over the same period, and the hen harrier population a 2% decrease.
The remaining 27 species are as follows: house sparrow, pied wagtail, mistle thrush, cuckoo, house martin, swallow, swift, raven, carrion crow, hooded crow, magpie, meadow pipit, stonechat, whinchat, woodlark, bearded tit, firecrest, Dartford warbler, cirl bunting, corncrake, quail, red grouse, collared dove, avocet, golden plover, black-headed gull, and Mediterranean gull. There is no long-term data for two of the species: the firecrest and the Mediterranean gull. As for the rest, the species that has seen the largest increase in the 1970 to 2015 period is the collard dove, with numbers up by 799%. Six other species have also seen large increases in the same period: avocet up by 320%; Dartford warbler up by 285%; woodlark up by 126%; carrion crow up by 98%; magpie up by 97%; and cirl bunting up by 79%. Eight species have experienced more modest increases, with stonechat increasing by 50%; raven by 38%; pied wagtail by 38%; hooded crow by 17%; black-headed gull by 16%; red grouse by 14%; bearded tit by 10%; and swallow by 8%.
Long-term declines for the house sparrow and summer migrants
On the negative news, the house sparrow has seen the largest long-term decline among the species in the ‘other’ group, with numbers down by 72% in 2015 compared to 1970. And compared with the swallow, four other summer migrants have fared badly in the same period, with cuckoo populations down by 57%, whinchat down by 52%, swift down by 51%, and house martin down by 11%. The remaining five species have also seen long-term declines, with mistle thrush down by 55%; corncrake down by 55%; quail down by 39%; meadow pipit down by 34%; and golden plover down by 20%.
In summary, while 22 of the 38 ‘other’ species have increased in the 1970 to 2015 period, 13 have declined, with the house sparrow and summer migrants most prominent among the ‘losers’. This is counterbalanced by the large increases in the populations of the collared dove, several birds of prey, several ducks, and a number of other species.
Wintering Waterbirds: A 92% increase since 1975/76
As well as the all-species index, Defra’s report contains data on wintering waterbirds, some of which also breed in the UK, and some of which are included in the all-species index. Defra says the data on wintering waterbirds is sourced from monitoring schemes that are largely based on full counts at colonies or at wetland and coastal sites of markedly varying size. In summary, the figures show that in the winter of 2014/15 the wintering waterbird index was 92% higher than in 1975/76, but the report says that the index peaked in the late 1990s and has largely declined since, with a short-term decline of 8% in the five years from 2009/10 to 2014/15. Defra says that “populations of wintering wetland birds are affected by a range of factors, including conditions in the countries where they breed, the condition and amount of coastal and wetland habitat in the UK, and changes in migratory patterns, at least some of which are known to have been affected by climatic changes.”
There are 46 species included in the wintering waterbird indicator, which Defra splits into two subcategories. The wildfowl category includes 27 species of ducks, geese and swans, whilst the wader category includes 15 species of sandpipers, plovers and their close relatives. There is also a third group of birds that do not fall into either category: these are the little grebe, great crested grebe, coot and cormorant, all of which are also included in the all-species index. The report says that the two main groupings display slightly different trends: overall, the figures show that the wildfowl index has more than doubled (an increase of 109%) since 1975/76, whilst the wader index has increased by 57% in the same period, but both peaked in the late 1990s and have declined since.
Wintering Wildfowl: Most ducks and geese have seen long-term increases
With regard to the wildfowl grouping, 11 of the 27 species also breed in the UK and are included in the all-species index. These are the mute swan, teal, mallard, tufted duck, and goosander (included in the wetland index), and the shelduck, gadwall, shoveler, pochard, red-breasted merganser, and greylag goose (included in the ‘other’ index). The other 16 species include 5 species of ducks that also breed in the UK but in smaller numbers and are not included in the all-species index. These are the wigeon, pintail, eider, goldeneye, and small numbers of scaup. The numbers of these residents are boosted by winter migrants, and they are joined by geese and swans that migrate to the UK from the Arctic, North America and Northern Europe for the winter. The non-residents in the wintering waterbird index include two varieties of swan (Bewick’s from Siberia and whooper from Iceland); two varieties of white-fronted goose (European and Greenland); two varieties of barnacle goose (Greenland and Svalbard); three varieties of brent goose (dark-bellied, Nearctic light-bellied, and Svalbard light-bellied); the Icelandic greylag goose; and the pink-footed goose.
Geese and Swans
The majority of the wintering geese and swan species have experienced large long-term increases in the 40-year period from 1975/76 to 2014/15. The resident greylag goose has increased in winter numbers by 3,647% (a 36-fold increase), whilst its Icelandic cousin has increased by 40%. Barnacle geese have also increased in the long term, with Svalbard numbers up by 526% since 1975/76 (a 5-fold increase) and Greenland up by 175% since 1988/89. Brent geese have all increased too, with the numbers of Svalbard light-bellied increasing by 584% since 1975/76 (roughly a 6-fold increase), dark-bellied increasing by 205% in the same period (a 2-fold increase), and Nearctic light-bellied up by 89% since 1987/88. As for the swans, the resident mute swan has increased in winter numbers by 171% since 1975/76 whilst the visiting whooper swan has seen a large increase of 289% in the same period (almost a 3-fold increase). However, the visiting Bewick’s swan has declined by 85% since the 1975/76 baseline and continues to decline strongly in the short term. The figures for the other migrants present a mixed picture. The numbers of pink-footed goose (visitors that fly south from Spitsbergen, Iceland and Greenland) have increased by 444% since 1975/76, and the Greenland white-fronted goose has increased by 17% since 1982/83. However, the European white-fronted goose has declined by 56% since 1976/76.
The majority of the ducks included in the all-species index have also seen long-term increases in the wintering waterbird index, with the gadwall population, boosted by visitors, increasing by 1,295% since 1975/76 (a 12-fold increase). Teal numbers have increased by 179%, shoveler by 106%, red-breasted merganser by 77%, tufted duck by 61%, goosander by 55%, and shelduck by 30%. However, pochard numbers have declined by 53% and mallard by 20% in the 40-year period. The majority of the other resident ducks have seen increases, with wigeon populations, boosted by winter visitors, increasing by 136% since 1975/76. Eider numbers have increased by 16% since 1986/87 (excluding eider colonies on Shetland), and the numbers of goldeneye (a duck that breeds in Scotland and is also a winter visitor) have increased by 11% since 1975/76. However, the numbers of wintering scaup (which breeds in very small numbers in the UK) have declined by 50% since 1975/76, and pintail numbers have declined by 17% in the same period.
Wintering Waders: A mixed picture
The wader group includes 15 species, 6 of which are also included in the all-species index. These are the curlew, lapwing, redshank, and oystercatcher (included in the wetland index) and the avocet and golden plover (included in the ‘other’ index). Two of the other 9 waders also breed in the UK: these are the dunlin and the ringed plover, whose numbers are boosted by visitors from Northern Europe and the Arctic in the winter. The remaining 7 waders in the wintering waterbird index are all visitors, migrating from northern locations such as Canada, Greenland, Iceland, Svalbard, Norway, Siberia and the Arctic. These are the turnstone, knot, sanderling, purple sandpiper, black-tailed godwit, bar-tailed godwit, and grey plover.
Of the resident waders, the avocet has seen the largest increase in winter numbers, up by 703% since 1988/89 (a 7-fold increase). Golden plover numbers have also increased, up by 183% since 1975/76. Lapwing numbers have increased by 81% over the same period, and curlew by 22%. Redshank and oystercatcher numbers have seen little change since 1975/76, with redshank down by 1% and oystercatcher up by 2%. For the other two breeding waders, not included in the all-species index, the news is not so good. Wintering numbers of dunlin have declined by 50% since 1975/76, and ringed plover numbers have declined by 40%.
Non-residents have seen the largest long-term increases among the wintering waders
Among the 7 non-resident waders, the black-tailed godwit (a visitor from Iceland) has seen the largest increase, with numbers up by 739% (a 7-fold increase) since 1975/76, while its cousin the bar-tailed godwit (a visitor from Scandinavia and Siberia) has seen little change (up by 1% over the same period). Two of the Arctic visitors have seen significant increases, with numbers of grey plover up by 123%, and numbers of sanderling up by 62%. The remaining three visitors have seen little change, with numbers of purple sandpiper up by 16%, knot up by 1%, and turnstone (a visitor from Canada and Greenland) down by 3%.
To summarise, it is mainly the non-residents that have witnessed the largest increases among the waders in the wintering waterbird index. With one or two exceptions, the resident species have not fared as well, with winter numbers showing either little change or evidence of decline.
The UK’s resident waders: Initiatives to halt the decline
Taken as a whole, Defra’s report provides a mixed picture of the state of the UK’s wild bird populations. The large rise in the numbers of wintering wildfowl visiting the UK can be explained by a number of factors, some of which would include factors impacting on their breeding patterns and locations far removed from the UK. With regard to the UK, however, one factor is undoubtedly land management and the number of restoration schemes undertaken by mineral extraction companies and quarry operators at former sites, many of which now provide a variety of habitats for birds and other wildlife, including lakes, ponds and wetlands, and are now managed nature reserves – see our article ‘Mineral Products Association celebrates quarry restoration at ‘Quarries and Nature 2015”. Yet many of the UK’s breeding waders, which depend on a range of habitats for feeding and breeding, have continued to decline, both as a resident and as a winter visitor.
A number of initiatives are currently taking place across the UK, aimed at halting the decline of our breeding waders. These initiatives have included land management schemes that can help ground-nesting birds, such as the curlew and lapwing, to breed successfully. There are 14 such projects taking place in Shropshire, Powys and the Welsh Marches, which together form the Stiperstones and Corndon Hill Country Landscape Partnership Scheme. One of these projects is the Lapwing Recovery Project. Some years ago, it was reported that lapwings were in danger of becoming extinct as a breeding bird in many parts of Shropshire.  One of those areas was the Upper Onny area, where a local wildlife group in collaboration with the Shropshire Wildlife Trust launched the Lapwing Recovery Project to work with local farmers in a move to halt the decline. A Countryside Stewardship Agreement with one local farm made provision for a rotating 20 acre field managed primarily for lapwings, with over-wintered stubble followed by a spring and summer fallow. Initial breeding success helped to reverse the decline, but more recent reports state that the number of breeding pairs is now “back to square one,” with the loss of habitat on the most important farm, and the abolition of set-aside on arable land, resulting in a further decline. 
Another one of these projects is the Curlew Country Project (also known as the Shropshire Hills and Welsh Marches Curlew Recovery Project) which began in 2014, initially to raise awareness among local farmers on the plight of the curlew and to undertake some lowkey monitoring. The current project is now wider and has been running for two years. Its aim is to “work constructively with land managers to find out what is preventing the curlew from breeding successfully and then taking pragmatic steps to save the curlew.”  The project is working with over 60 farmers and land managers and has recruited field ornithologists to carry out three years of nest monitoring to find out why local birds are failing to breed successfully. During the curlew breeding seasons of 2015 and 2016, field ornithologists monitored over 30 nests using cameras, thermal data loggers, and close observation techniques. They have reported that only 3 nests in each year survived beyond egg incubation stage to hatch chicks, whilst no chicks survived to fledgling stage. The results of the monitoring have shown that predation is the most urgent problem when addressing nest failure at egg stage, with foxes being the main culprit. To prevent predation from foxes, the project is working with a European partner on a trial of protective electric fencing, and two such trials have been implemented in “predation control areas” of a thousand hectares. 
The project reports that the UK hosts around 25% of the international curlew population, and that rapid declines across Europe have led the International Union for the Conservation of Nature (IUCN) to classify the Eurasian Curlew as ‘vulnerable’ on the European Red List, meaning that the species is at risk of extinction.  Curlew breed on farmland and adjacent wet areas as well as moorland and upland areas, but this recovery project has a specific focus on farmland habitat:
“The Shropshire & Welsh Marches Recovery Project study area is central in the investigation into what can be done to reverse the decline in the UK and wider European Curlew populations. The area is located on the Powys Shropshire border and is home to both lowland and upland species. This ecological hinterland between upland and lowland, north and south, is the breeding ground for a small population of about 40 pairs of breeding Curlew. This regional stronghold is one of only a handful of known population groups of this size, outside managed moors and reserves in the north.”
The hills of Shropshire and the Welsh Marches have, in the past at least, provided a number of suitable habitats for curlews to breed, but the Curlew Country Project says that, locally, numbers have declined by over 30% in 11 years. Though it does not prevent the problems of predation, the creation and conservation of suitable habitat is an obvious step in reversing this decline. Many of the recovery projects in the Shropshire Hills AONB (Area of Outstanding Natural Beauty) are concerned with farmland and land management schemes, but these schemes are complemented by nature reserves and local wildlife sites, which include upland habitat such as Catherton Common, where the cry of the curlew can sometimes be heard in the spring. Catherton Common is an area of uncultivated heath near the Clee Hills which is covered in several varieties of vegetation, including bracken, heather, furze and boggy pools. The Common was purchased by the Shropshire Wildlife Trust in 2009 and is now a managed nature reserve and SSSI (Site of Special Scientific Interest). In its literature, the Trust describe it as one of the most botanically-rich places in Shropshire and “a wonderful place for many birds that have vanished from other parts of the county.” 
The work of maintaining these reserves, and the monitoring of bird populations, could not be achieved without the help of volunteers and community wildlife groups. There are eight such groups in the Shropshire Hills AONB, one of which is the Strettons Area Community Wildlife Group. In 2016, the group coordinated biodiversity surveys of a marshy area the size of 11 hectares on the southern edge of Church Stretton and recorded sightings of kingfisher, egrets, kingfisher and snipe among numerous other birds. The findings were collated and submitted to Shropshire Wildlife Trust who then submitted a proposal to Shropshire Council to register the site as a Local Wildlife Site. In January 2017, the group announced that two-thirds of the site had now been registered which means that the Stretton Wetlands has now been acknowledged as a new Local Wildlife Site. In its annual report, the group says: “A wildlife site provides some protection from harmful development but still enables landowners to continue to manage their land, including grazing, and does not prevent planning requests and development on adjacent land. It may also improve the possibility of obtaining funding to develop the biodiversity.”  This may not be of immediate assistance to the curlew, but it does provide an optimistic note on which to conclude.
Photograph: Curlew on the Pyewipe Mudflats, Humber Estuary © Copyright Mat Fascione and licensed for reuse under this Creative Commons Licence. The Curlew Country Project reports that the curlew is the UK’s largest wader and is now considered to be the highest bird conservation priority. The curlew has a long life, “exceptionally for 20 or 30 years.”
 Wild Bird Populations in the UK, 1970-2016, Biodiversity Statistics Team, Department for Environment, Food and Rural Affairs, 23/11/2017. Available as a PDF document from: https://www.gov.uk/government/statistics/wild-bird-populations-in-the-uk.
 A sizeable chunk of Defra’s report is concerned with the methodology of statistical analysis and the meaning of terms used in the report. In particular, “short-term” refers to an assessment of change over the latest five years (in most cases, 2010 to 2015), while “long-term” refers to an assessment of change since the earliest data became available, which varies among indicators and species. The report also attaches statistical meanings to the words “strong” and “weak” when describing trends: for instance, a “strong increase” means a population increase of 100% or more, whereas a “strong decline” means a population decrease of 50% or more. A “weak increase” means an increase in the range of 33% to 100%, while a “weak decline” means a decrease in the range of 25% to 50%. In the middle, we have “no significant change,” which means figures ranging from a 25% decrease to a 33% increase. However, in the figures presented for individual bird species, Defra uses the words “strong” and “weak” with a flexibility that appears to undermine their statistical definitions. An analysis of Defra’s figures is rendered even more difficult by the use of two terms to describe statistical trends, explained as follows: “Two trends are referred to in the text: the unsmoothed indices show year-to-year fluctuation in populations, reflecting the observed changes in the survey results; and smoothed trends, which are used to formally assess the statistical significance of change over time. Smoothed trends are used for both long and short-term assessments as they reduce the short-term peaks and troughs resulting from, for example, year-to-year weather and sampling variations as well as good or bad breeding seasons.” Throughout this article, the figures are taken from the smoothed indices, except for the seabirds, for which no smoothed trends are available.
 On the causes of wildlife decline in the UK, see also the habitat analysis in the ENA article, ‘The State of Nature 2016 – New report examines the causes of wildlife decline in the UK’.
 Mark Easton, ‘How much of your area is built on?’, BBC News, 09/11/2017. Retrieved from: http://www.bbc.co.uk/news/uk-41901294. “Every council area in the UK has been analysed and individual maps produced showing how much of the area falls into four land categories: farmland, natural, built on, and green urban.” The research provides the facility to discover “at the click of a button” exactly how the land is used in a local authority area by keying in a postcode.
 Mark Easton also discusses the methodology for classifying ‘discontinuous urban fabric’ as ‘green urban’. See: ‘Five mind-blowing facts about what the UK looks like,’ Mark Easton, BBC News, 09/11/2017. Retrieved from: http://www.bbc.co.uk/news/uk-41901297. Defra says that 75% of land in the UK is devoted to agriculture, but this is clearly an error. The figure of 75% would represent an estimate of land in England devoted to agriculture, but not of land in the UK as a whole.
 The IUCN (International Union for Conservation of Nature) uses a range of categories to assess the status of a species with regard to its population and the priorities for conservation. These are: 1. Extinct; 2. Extinct in the wild; 3. Critically Endangered; 4. Endangered; 5. Vulnerable; 6. Near Threatened; 7. Least Concern; 8. Data deficient; and 9. Not evaluated. The turtle dove is listed as ‘critically endangered’ in the UK and ‘vulnerable’ globally.
 See: Operation Turtle Dove.
 For news of these initiatives, see the ENA UK article, ‘Mineral Products Association celebrates quarry restoration at ‘Quarries and Nature 2015”. The RSPB is also engaged in a number of collaborative schemes with farmers and landowners aimed at halting the decline of the twite. See: ‘Bringing Twite Back’, Kathryn Smith, RSPB, 27/09/2017. Retrieved from: http://www.rspb.org.uk/community/ourwork/farming/b/farming-blog/archive/2017/09/27/bringing-twite-back.aspx.
 ‘Preliminary estimates of the changes in canopy cover in British woodlands between 2006 and 2015 – National Forest Inventory’, Forestry Commission, August 2016. Available as a PDF document from https://www.forestry.gov.uk/pdf/Preliminary_estimatesofthechangesincanopycoverinBritishwoodlandsbetween2006and2015.pdf.
 See the “Our Views” item on the Woodland Trust website at https://www.woodlandtrust.org.uk/get-involved/campaign-with-us/our-campaigns/hs2-rail-link/.
 Elsewhere, Defra gives the figure of 20% (not 22%) for the decline of seabirds in the same period (1986 to 2014). Both figures are “unsmoothed indices” (see Note 2) and it is therefore unclear which is the correct figure. In this article, we have assumed the 20% figure.
 See the ‘Case Study and Fact Sheet’ for the Lapwing Recovery Project, produced in 2008 by the Upper Onny Wildlife Group in collaboration with the Shropshire Wildlife Trust. Available as a PDF document from: http://www.shropshirehillsaonb.co.uk/wp-content/uploads/2010/10/Lapwings_Project.pdf. The Shropshire Biodiversity Partnership adopted a ten-year Lapwing Action Plan which is available as a PDF document from: https://shropshire.gov.uk/media/1855/sbap-lapwing-2009.pdf. The plan was first published in 2006 with many of the actions set to continue until 2015. See also the advice sheet for farmers, landowners and contractors, published by the Stiperstones and Corndon Hill Country Landscape Partnership in 2014. Available as a PDF document from: http://www.stiperstonesandcorndon.co.uk/wp-content/uploads/2014/06/Lapwing-leaflet-IMPRINT-final.pdf.
 See the Upper Onny Wildlife Group project results at: http://www.shropscwgs.org.uk/sample-page/project-results/.
 See the Curlew Country Project website at: https://curlewcountry.org/project-background/.
 See the Curlew Country Project website at: https://curlewcountry.org/what-are-we-doing-and-hope-to-do/. The ‘Case Study and Fact Sheet’ for the Lapwing Recovery Project, produced in 2008 by the Upper Onny Wildlife Group (Note 12), highlights carrion crows as the main predator in the case of lapwing nests. Climate change may also be playing a part in the decline of breeding waders. A report by the British Trust for Ornithology on the 2011 Breeding Bird Survey suggested that unfavourable weather conditions have exacerbated their long-term decline. Grahame Madge, a press officer for the RSPB and also for the Met Office, said: “The spring of 2012 has seen the wettest April to June period on record, and it’s likely that populations of these ground-nesting waders would have also been hit hard this year. Flooding at several key sites has seen hundreds of wader nests washed out, including 600 at the RSPB’s Ouse Washes reserve in Cambridgeshire.” See: ‘Lapwings hit new low; further declines in breeding waders revealed’, British Trust for Ornithology, July 2012. Retrieved from: https://www.bto.org/news-events/press-releases/lapwings-hit-new-low-further-declines-breeding-waders-revealed.
 See the Curlew Country Project website at: https://curlewcountry.org/eurasian-curlew/. On the International Union for the Conservation of Nature (IUCN) Red List, see Note 6.
 See the Shropshire Wildlife Trust website at: https://www.shropshirewildlifetrust.org.uk/reserves/catherton-common. In February 2017, an application to build four holiday chalets near the reserve, with associated access and car parking facilities, was refused permission by Shropshire County Council on the grounds that such a development would be contrary to local and national planning policy and that any benefit to the rural economy would be outweighed by the environmental harm, as the site was not only adjacent to the Common but also “within both a buffer zone and corridor of the Shropshire Environmental Network.” See the Shropshire Council website at: http://shropshire.gov.uk/news/2017/02/decisions-made-by-south-planning-committee-on-7-february-2017/.
 See the annual report of the Strettons Area Community Wildlife Group, available as a PDF document from: http://www.shropscwgs.org.uk/wp-content/uploads/2012/11/SACWG-annual-report-2016-draft-AJA.pdf.