Dorset Butterfly Has A Bad Year
Some of Britain's most threatened butterflies appear to be showing signs of recovery after decades of decline, experts said today.
A monitoring programme run by Butterfly Conservation and the Centre for Ecology and Hydrology saw rare species including the wood white and the marsh fritillary record large increases last year.
Experts said the improvement in the butterflies' fortunes was likely to be the result of targeted conservation action - and better weather in 2010 than the past few years.
But one of the UK's rarest butterflies, the Lulworth skipper, which is confined to the Dorset coast, had its worst year since the monitoring scheme began in 1976, and there are concerns that managing landscapes to benefit other species may be harming the skipper.
Meadow browns, one of the country's most common species, also had its worst year on record, while Essex skippers, small skippers and wall butterflies also fared badly.
Butterfly Conservation said overall butterfly numbers continued to decline, with three quarters of the nearly 60 species found here seeing numbers fall in recent decades and nearly half of them seriously threatened.
Most of the at-risk species are in long-term decline, but three quarters of the threatened species did see an increase in numbers in 2010 on 2009 levels.
The wood white, which has suffered a 96% decline since the 1970s, saw numbers increase last year by 600%, while the marsh fritillary, in decline since the 1950s, more than doubled its numbers from 2009 to 2010.
Dr Tom Brereton, head of monitoring at Butterfly Conservation, said the increase in ''specialist'' species which rely on a particular habitat showed that conservation efforts to restore those areas were helping - once the species had good weather.
Butterflies were badly hit by three poor summers before better weather last year, while a cold winter in 2009/2010 will have helped check parasites and stop butterflies emerging too early, helping the insects breed successfully.
Dr Brereton said:
''There has been a lot of good conservation efforts over the last decade or so, but the last few years haven't had the weather to go with it.''
He said projects to restore landscapes had particularly helped the wood white and the marsh fritillary, while some other species were also beginning to recover.
''It shows these projects are working, given time. This is extremely welcome news and shows that we can reverse butterfly losses if the effort can be maintained. There's no doubt that other wildlife is benefiting too.''
Dr Marc Botham, butterfly ecologist at the Centre for Ecology and Hydrology, said: Butterflies are highly sensitive to how our countryside is changing and the UK butterfly monitoring scheme data has revealed how butterflies are already impacted by climate change as well as whether our conservation measures are working.''
He said that species such as the brown argus, which has moved into new areas and north west as it has shifted to feeding from a species of geranium that has become more widely available as the climate warms, were adapting to rising temperatures.