Members of the public are being asked to help scientists track the impacts of climate change on butterflies, as data shows the insects are on the move north.
After analysing 50 years of data, researchers have discovered a northward spread for many species, including common garden butterflies such as the peacock, comma and holly blue, as climate change creates warmer habitats for them to survive in.
Other species on the move include the Jersey tiger, a day-flying moth found only in south-west England but which has been spotted as far north as central London in recent years, and the Scotch argus in Scotland, which is retreating northwards to stay in the cooler climate it prefers.
Wildlife charity Butterfly Conservation is asking people to take part in the annual Big Butterfly Count, to help scientists understand more about the northward move of butterflies as temperatures rise.
To take part in the count, the charity says people just spend 15 minutes in any sunny spot and record the number and type of butterflies they see – or even if they do not see any at all, which is also important information for the experts.
This year, there has been a noticeable lack of butterflies, the charity says, likely to be due to the wet spring and now the colder-than-normal conditions, which butterflies struggle in because they need some warmth and dry weather to be on the wing.
Butterfly Conservation also warns that 80% of species of butterflies – which are indicators of the health of the natural environment – have declined since the 1970s, due to habitat loss, changes to farming, pesticides, and climate change.
That makes populations less resilient to the impact of poor weather, the charity said.
The warming temperatures are affecting different species differently, with holly blues now turning up in Scotland as they expand their range in the UK by 34%, and red admirals, a migratory species which left for Europe in the winter, now living in the UK all year round and increasing their numbers three-fold.
Dr Zoe Randle, senior surveys officer at Butterfly Conservation, said: “We’re also seeing other species which have previously suffered severe declines, such as the comma, recovering, with a huge increase of 94% in where it is found.
“These highly adaptable species are all able to move into new places as the climate warms, but for habitat specific species these trends raise serious red flags.
“Species that rely on particular habitats aren’t able to move as freely as our garden favourites.
“This means that, if climate change continues, they could become trapped in isolated fragments of remaining habitat, unable to move and with their food plants at risk from adverse weather conditions, facing the very real threat of extinction.”
Butterfly Conservation vice president and TV presenter Chris Packham urged members of the public to take part in the count to help conservationists take action to save wildlife.
He said: “Butterflies are on the move, and there’s no doubt that climate breakdown is behind these geographic shifts.
“We know nature is running out of time, so we need to act now. We need you to get out for the Big Butterfly Count. Let us know what you spot and where you spot it.
“You will be gathering the important data we need to see what the latest impacts are on our butterflies and moths, so that we can take the action needed to protect them.”
– This year’s Big Butterfly Count runs from Friday July 12 to Sunday August 4. For more information and to take part, people can visit www.bigbutterflycount.org or download the free Big Butterfly Count app.