C5. Birds of the wider countryside and at sea

Figure C5ai. Breeding farmland birds in the UK, 1970 to 2019.

Figure C5bi. Breeding woodland birds in the UK, 1970 to 2019.

Figure C5ci. Breeding water and wetland birds in the UK, 1975 to 2019.

Figure C5di. Breeding seabirds in the UK, 1986 to 2019.

Figure C5ei. Wintering waterbirds in the UK, 1975/76 to 2018/19.

Assessment of change in bird populations

Notes:

1. Whilst latest year percentage changes in these indices are reported based on the most recent unsmoothed data point (2019), the formal long-term and short-term assessments of the statistical significance of these changes are made using the smoothed data to 2018. This is because the most recent smoothed data point (2019) is likely to change in next year’s update when additional data are included for 2020.
2. Analysis of the underlying trends is undertaken by the data providers. Smoothed data are available for farmland, woodland, wetland and wintering waterbirds, but not for seabirds.
3. The traffic light assessment for the seabirds measure has been removed until a way of assessing variability is devised. This follows recommendations in a quality assurance science panel report, dated January 2016.

 The long-term decline of the farmland bird indicator in the UK has been driven mainly by the decline of those species that are restricted to, or highly dependent on, farmland habitats (the ‘specialists’, which account for 12 of the 19 species in the indicator). Between 1970 and 2019, the unsmoothed index for farmland specialists declined by 70% while for farmland generalists it declined by 13%. Of the 12 farmland specialists, five (corn bunting, grey partridge, starling, turtle dove, and tree sparrow) have undergone declines in excess of 80% since 1970 due largely to changes in farmland practices. Two farmland specialists (stock dove and goldfinch) have more than doubled over the same period, illustrating how responses to pressures varies among species. Generalist species have fared better than specialists although the rates of decline have been more alike during the last decade. Amongst the generalists, woodpigeon and jackdaw populations have more than doubled relative to 1970 levels, whereas the yellow wagtail has declined by 68%, greenfinch by 64% and kestrel by 48%. Overall, farmland birds have been impacted by changes in the suitability of farmland for breeding and wintering as well as pressures faced by those that undertake long migrations. However, most farmers can and do take positive steps to conserve birds on their land. In particular, a number of incentive schemes 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 stubbles and planted wild bird crop covers to provide seed in the winter, uncropped margins on arable fields and sympathetic management of hedgerows. There is growing evidence that such action can deliver local recoveries in farmland bird populations and thus, if delivered at appropriate scale, wider recovery. The decline in greenfinch is considered to be caused by the disease trichomonosis.

 The woodland bird index contains data for 37 species. The relatively flat trend for all woodland birds since the mid-1990s masks different underlying trends for specialist species, those which are highly dependent on woodland habitats, and generalist species, which are found in a wide range of habitats, including woodland. In 2019, the woodland specialists index was 45% lower than in 1970, while the index for woodland generalists was 11% higher than in 1970. Indices for four generalist woodland species (bullfinch, song thrush, dunnock and tawny owl) have declined more than 30% since 1970; and song thrush by 49%. Over the same period, populations of long-tailed tit and great tit increased by 102% and 79% respectively. Five woodland specialists, lesser spotted woodpecker, lesser redpoll, spotted flycatcher, capercaillie and willow tit, have declined by over 80% relative to 1970 levels, with the latter down by 94%. In contrast, populations of blackcap have more than doubled over the same period and nuthatch and great spotted woodpecker have more than trebled in numbers. Trends in long-distance migrants may possibly reflect changing conditions on their wintering grounds whereas declines in residents such as lesser spotted woodpecker, willow tit and capercaillie must be due to factors on their breeding grounds. Probable causes for this include a lack of woodland management (including the cessation of traditional practices such as coppicing) and increased deer browsing pressure, both of which result in a reduced diversity of woodland structure and reduced availability of suitable nesting and foraging habitats. 

 The breeding water and wetland bird measure can be disaggregated to four sub-habitat indicators (birds of fast flowing water, birds of slow and standing water, birds of reedbeds and birds of wet grasslands) although each is composed of relatively few species. Birds of slow flowing and standing water, including mallard and tufted duck, have shown the most positive trend. In 2019 the index for this group was 33% higher than in 1975 although there has been a significant 7% decrease in the short-term period between 2013 and 2018. The index of birds of wet grassland, including a number of wader species, has decreased by 52% since 1975, and the index for birds of fast flowing water (including dipper) decreased by 29% compared to 1975. 

 The seabird measure is focussed on the marine environment. Accordingly, for a number of species (e.g. herring gull, great cormorant), the indicator uses data for coastal populations (colonies within 5 km of the coastline) only, rather than data from all breeding areas of these species. This focusses the indicator on changes at the coast and in marine waters but means changes in inland populations are not taken into account. In 2019, the breeding seabird index in the UK was 24% lower than in 1986, slightly above the lowest level ever recorded (of 31% lower than 1986, recorded in 2013). Despite fluctuations, the indicator was largely flat from 1986 until the early-2000s when seabird numbers started to decline and the long-term trend (to 2018) shows a significant 28% decrease. However, more recently the unsmoothed breeding seabird index has increased, non-significantly, by 3% between 2013 and 2018. One of the 13 seabird species has increased since the beginning of the index in 1986; razorbill numbers have more than doubled. Two species have declined strongly since 1986; Arctic skua by 80% and black-legged kittiwake by 64%. The decline of black-legged kittiwakes has been linked to climate change impacts on marine food webs, and fishery pressures. However, there has been some improvement in the short term, during which black-legged kittiwakes have shown a strong increase, of 20% between 2013 and 2018. In addition to black-legged kittiwakes another two of the 13 seabird species have increased strongly between 2013 and 2018; razorbill and sandwich tern by 35% and 26% respectively. Numbers of great black-backed gull are decreasing strongly by 32% in the short term, although the long-term trend is a weak decline. 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 wintering waterbird measure increased steadily from the 1975 to 1976 baseline to a peak in the late 1990s and has declined since. The indicator in 2018 to 2019 stands 88% above its 1975 to 1976 baseline. The separate wader and wildfowl indices show broadly similar patterns of increase followed by decrease, although the change in the wildfowl indicator has been greater. Amongst wildfowl, five of the 27 species showed a weak decline, with the indices for the European white-fronted goose, pochard, Bewick’s swan, and scaup halving since 1975 to 1976. Numbers of eider have declined by 35%. Gadwall and British/Irish greylag goose have increased by 15 and 13-fold respectively in the long term. Since 1975 to 1976, both the Svalbard Light-bellied Brent goose and whooper swan have increased nine-fold. Svalbard barnacle goose increased seven-fold and pink footed-goose by six-fold in the long term. Amongst waders, 40% of the species have increased, 53% showed little change and 7% have declined since the winter of 1975 to 1976. The indices for two waders (avocet and black-tailed godwit) have increased over eight-fold (avocet is only included in the indicator since 1989 to 1990). The indices for dunlin and ringed plover showed the steepest declines, declining by 49% and 36% respectively, since the winter of 1975 to 1976.

Aichi Targets for which this is a primary indicator

Strategic Goal B. Reduce the direct pressures on biodiversity and promote sustainable use.

Target 7: By 2020, areas under agriculture, aquaculture and forestry are managed sustainably, ensuring conservation of biodiversity.

Strategic Goal C. To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity.

Target 12: By 2020, the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

Aichi Targets for which this is a relevant indicator

Strategic Goal B. Reduce the direct pressures on biodiversity and promote sustainable use.

Target 5: By 2020, the rate of loss of all natural habitats, including forests, is at least halved and where feasible brought close to zero, and degradation and fragmentation is significantly reduced.

Strategic Goal C. To improve the status of biodiversity by safeguarding ecosystems, species and genetic diversity.

Target 11: By 2020, at least 17 per cent of terrestrial and inland water, and 10 per cent of coastal and marine areas, especially areas of particular importance for biodiversity and ecosystem services, are conserved through effectively and equitably managed, ecologically representative and well connected systems of protected areas and other effective area-based conservation measures, and integrated into the wider landscape and seascapes.