The State of the UK’s Butterflies
- Published on Friday, 09 December 2011 10:26
- Written by Richard Fox
Three quarters of UK butterfly species are in decline according to a major scientific report published this week. The State of the UK’s Butterflies 2011 produced by Butterfly Conservation and the Centre for Ecology & Hydrology is based on data gathered by two world-leading citizen science projects involving thousands of members of the public
The results demonstrate that the 2010 EU target to halt the loss of biodiversity was not met for the UK’s butterflies. Ten-year trends show that 72% of species declined in abundance and that the UK distributions of 54% of butterflies also declined. Overall, three-quarters of species showed a 10-year decrease in either their distribution or population levels.
Butterflies with specific requirements for particular habitats, such as chalk downland and ancient woodland, have continued to decrease in recent years, following decades of decline. Examples include the High Brown Fritillary and Duke of Burgundy. The High Brown Fritillary’s population has fallen by 69% and its distribution has plummeted by 49% in just 10 years.
The report also reveals that for the first time, a significant (24%) decrease in the overall numbers of common butterflies has also been recorded over 10 years, indicating a much-wider malaise in the UK’s environment.
The ongoing deterioration of habitats is the main cause of these declines, resulting from inappropriate management (e.g. continued intensification or abandonment) or insufficient quantity, quality or targeting of favourable management. Highly variable summer weather may also be contributing, counteracting the mainly beneficial effects of climate warming.
The report has some positive findings too. A few species, such as the Peacock, Comma and Speckled Wood, have spread northwards in response to climate warming. In addition, there are promising signs that some highly threatened butterflies are recovering due to conservation initiatives.
The previously extinct Large Blue has spread to form around 20 new colonies and the Heath Fritillary has been brought back from the brink of extinction. This demonstrates that declines can be reversed through the species-focussed action or targeted grant schemes, given sufficient time and resources.
UK butterflies are thus still in serious decline and remain one of our most threatened wildlife groups. Highly targeted, species-focussed approaches will be crucial to meet UK and EU policy objectives and can be delivered through landscape-scale conservation projects or ‘higher level’ agri-environment schemes and woodland grants.
Unfortunately, the recent Natural Environment White Paper and new England Biodiversity Strategy shift the focus away from threatened species in favour of the generic management of habitats and ecosystem services.
These, together with a massive cut in Natural England’s funding for threatened species, jeopardise the recent improvements for some endangered butterflies and make it much less likely that the declines of the UK’s butterflies will be halted or the 2020 EU biodiversity target achieved.
The State of the UK’s Butterflies 2011 report shows that a strong focus on threatened species in future Government policy is vital to halt the loss of biodiversity and to meet the new EU target to halt the loss of biodiversity by 2020. Butterfly populations, which are used by the UK Government as official indicators of biodiversity and the environment, also provide an excellent means of monitoring progress towards this target.
The full report can be viewed at http://www.butterfly-conservation.org/article/9/269/decade_of_decline_for_uk_butterflies.html
Butterfly Conservation is a UK charity that aims to secure a lasting future for butterflies, moths and the environment. For more information visit www.butterfly-conservation.org