Britons are being urged to take part in an annual count of butterflies amid fears their numbers have been hit by an unseasonably cold and wet spring.
April was the sunniest on record, but it was also cold with a record number of frosts, while May was the wettest for 50 years.
Conservationists warn that the UK is experiencing an increasing number of extreme weather events as a likely consequence of climate change, and they need the public’s help to measure the impact on butterflies and moths.
Butterfly Conservation’s current records show many species of butterflies have had a poor spring or a delay in their emergence due to the weather.
TV presenter and naturalist Chris Packham said taking part in the wildlife charity’s Big Butterfly Count – which starts today and lasts three weeks – could help provide vital research into the impacts of climate change on wildlife.
To take part, people just need to spend 15 minutes in an outdoor space, counting the number and type of butterflies, and some day-flying moths, they see – and log their findings on the Big Butterfly Count website or app.
Wildlife broadcaster Packham, who is vice president of Butterfly Conservation, said: "Because butterflies and moths make excellent indicators of the impacts of climate change and other human environmental factors, collecting data on their numbers is really important.
"So, something as simple as recording a butterfly spotted in your garden, at your local park or on your window box can play a part in vital research into a global problem.
"It’s a really valuable contribution everyone can make."
The annual counts and other research by the charity is already showing changes in the populations of butterflies and moths.
Species are being discovered in new areas, while others are becoming harder to find at all in the UK.
The Jersey tiger, a striking moth which flies during the day as well as the night, appears in this year’s Big Butterfly Count identification chart for the first time.
Research indicates the species has become well established along the south coast of England, but is moving further north and is now being found in increasing numbers in London.
Last year more than 145,000 counts were submitted to the Big Butterfly Count, a record for the scheme, but 2020 saw the lowest average number of butterflies logged since it began 12 years ago.
Dr Zoe Randle, senior surveys officer at Butterfly Conservation, said: "We really need the public’s help to understand what is happening to our butterfly and moth populations. It’s a small but crucial thing everyone can do.
"This information will not only help us to protect these species, but also to inform what effect the changing climate is having on our biodiversity."
This year’s Big Butterfly Count runs nationwide from 16 July to 8 August.