Our butterflies are in trouble. Butterfly Conservation and its partners have produced three influential State of Britain's/UK's Butterflies reports, which summarise the key results and conservation implications of our recording and monitoring programmes.
The most recent was published in 2011 (with previous ones in 2007 and 2001).
"The State of the UK's Butterflies 2011" was published by Butterfly Conservation in collaboration with the Centre for Ecology & Hydrology, and summarises the findings of over 10 years of intensive survey, monitoring and conservation effort. The report is based on millions of butterfly records collected by over ten thousand volunteers through the Butterflies for the New Millennium recording scheme and UK Butterfly Monitoring Scheme.
The report highlights the continuing decline of the UK's butterflies, measured by the changes in their distribution and population levels over a 10-year period and the implications for conservation.
Key findings include:
- Many butterflies have continued to decline: 72% of species decreased in abundance over 10 years and 54% decreased in distribution at the UK level. Overall three-quarters of UK butterflies showed a 10-year decrease in either their distribution or population levels.
- For the first time, a significant decrease in the total numbers of wider countryside butterflies have been recorded. The abundance of these common, 'garden' butterflies dropped by 24% over 10 years.
- Many habitat specialist species have continued to decline too (e.g. High Brown Fritillary, Duke of Burgundy, Pearl-bordered Fritillary), placing them at greater risk of extinction.
- However, there is some positive news too. A few threatened species have increased or stabilised due to intensive conservation effort over the past decade (e.g. Heath Fritillary, Large Blue, Marsh Fritillary, Silver-studded Blue).
- A minority of wider countryside species have continued to spread northwards, almost certainly in response to climate change (e.g. Peacock, Comma, Speckled Wood).
- Overall the findings confirm that the 2010 European Union target to halt the loss of biodiversity was not met for the UK's butterflies. A huge challenge remains to achieve the same aim by 2020.
- However, highly focussed and targeted conservation work, carried out under the UK Biodiversity Action Plan and 'higher level' agri-environment schemes, is starting to turn around the fortunes of some highly threatened species. This work must continue and, indeed, be scaled-up over the coming decade if we are to secure a future for the UK's butterflies.
The State of the UK's Butterflies 2011 also stresses the important role that butterfly recording and monitoring is playing in providing a sound evidence base for policy development and scientific research. UK Butterflies are probably the best monitored group of insects in the world and act as flagship species with wide popular appeal. Butterflies are also recognised as sensitive indicators of environmental change, including climate change, and of the health of the countryside.