The number of breeding birds in the UK has fallen by 44m since the 1970s.
That’s just one of the shocking statistics highlighted in the new State of Nature 2019 report, the third of its kind to detail how the country’s wildlife has changed over the past four decades.
The report – produced by a partnership of more than 70 nature-based organisations including the RSPB, Plantlife and The Wildlife Trusts – evaluates whether our actions are helping, or hindering, nature.
The report shows most species have declined since the 70s, and continue to decline today. As its authors put it: “There has been no let-up in the net loss of nature”.
There are some positives: of the 696 terrestrial and freshwater species monitored, 26% showed increases in abundance, and 36% increased when looking at the past decade alone.
Nevertheless, the UK’s wildlife has already been decimated through centuries of threats, including persecution and pollution, so current figures highlight only a small proportion of nature loss.
Here are the top five threats:
Change in agricultural practices
More than two thirds of UK land is currently managed to produce food for subsistence and profit. The past 50 years has seen more mechanisation, increased use of pesticides and fertilisers, and the removal of features like hedgerows, field margins and ponds.
This has been great for productivity but terrible for wildlife, making agricultural practices the main threat to UK biodiversity. Native red squirrels are being outcompeted by invasive grey squirrels.
For instance, the report highlights how a simple change to autumn sowing of crops has devastated skylark populations by causing a loss of over-winter seed availability, and creating crops that are too tall and dense to support nesting late in the season.
Consequently, farmland bird populations have declined by 54%. Nature-friendly farming – both voluntary and supported by government-funded agri-environment schemes – encourages less pesticide use, reverting to spring-sown cereals, and reinstating hedgerows and field margins, which have the potential to halt and reverse species declines.
So far, these declines have only been slowed, highlighting the complex interactions of threats, and lack of coordinated action on a landscape scale.
Pollutants include plastic waste, light and noise, or chemicals in water, soil and air, with new pollutants such as pharmaceuticals continuing to emerge. Transport, industry and farming are key pollution sources.
Nitrogen enrichment, caused by the burning of fossil fuels such as natural gas, has produced a decline in more than 60% of wildflower species that, in turn, impact on the moth larvae that depend on them.
The good news is that coordinated legislative control across Europe has caused marked reductions in many of these pollutants. Since the 1970s, the report notes that sulphur emissions from coal-fired power stations that cause acid rain have decreased by 97%.
And the River Thames, previously declared “biologically dead”, supported at least 100 seal pups this year – it’s one of the 35% of water bodies now classed as high or good according to the EU Water Framework Directive.
The UK’s skylark population halved during the 1990s, and is still declining.
Since the 1980s, UK temperatures have increased by 1℃. This affects the range and abundance of certain species, and throws the timing of key events out of sync – plants and invertebrates now respond to the arrival of spring four days earlier, yet birds only respond two days earlier, causing the availability of prey and the timing of peak predator requirements to become misaligned.
Species have also moved north by around 20 kilometres per decade, but these shifts rely on suitable habitat, so the impacts of climate change can be exacerbated through threats like agricultural management.
Climate change mitigation schemes protect nature-rich areas – protected areas are four times more likely to be colonised by species – and large-scale restoration projects have commenced, such as blocking drainage ditches and creating bunds to hold water within bogs that have been lost through drying.
Urbanisation has fragmented the landscape and lost valuable habitat. For instance, the report notes the loss of heathland across the UK has caused a decrease in the number of reptiles such as sand lizards and smooth snakes.
Planning policy in England and Wales now encourages new developments to create net gains for nature.
Habitat restoration schemes including Naturehood, supported by the National Lottery Heritage Fund, encourage people and communities to work together to enhance green spaces such as gardens, parks, allotments, and ponds, to create connectivity between habitats and enhance ecosystem function.
Many species such as foxes and peregrine falcons have adapted to urbanisation, and gardens are now recognised as pollinator hotspots.
Introduction of non-native species
More than 2,000 non-native species have established themselves in the UK, and they bring a variety of threats. Some out-compete native species, such as the American mink and the native water vole.
Others spread disease that only natives are susceptible to, shown by the American grey squirrel who passes pox on to our native red squirrel, while others hybridise with natives – think of the domestic cat hybridising with Scottish wildcats.
They can also impact on natives indirectly – the pathogen that causes ash dieback also affects insects, lichens, mosses and liverworts that rely on ash.
Consequently, non-natives have been implicated in 58% of the 247 animal extinctions where the cause is known.
Although preventing establishment is preferential, the management of non-native species and reintroduction schemes have shown some success – for instance successful rat eradication on several islands has helped native seabirds.
Clearly, the State of Nature report shows that conservation measures can benefit wildlife.
However, as species are usually impacted by a combination of factors, a holistic approach is needed and what the report does not highlight is that unless there is a societal gain, there is often a lack of appetite to make progress.
Although public sector expenditure on biodiversity conservation in the UK has declined in the last decade, non-governmental expenditure has increased, indicating growing public concern.
Indeed, the response to the plastic waste crisis demonstrates widespread appetite for a positive change. It is time to take drastic action.
This article is republished from The Conversation