Big Butterfly Count: scientists need help more than ever as record-breaking heat risks population 'crash'

Scientists urgently need Britons help to after last year's record high temperatures, as climate change risks many popular garden butterflies disappearing from the British backyard forever.

The 2023 Big Butterfly Count began on Friday (14 July), and will run until 6 August. Butterfly Conservation is calling on people across the UK to take part in the citizen science project, to help researchers understand the impact of climate change on the UK's most-loved butterflies.

Butterflies are indicator species - and if there are plenty about, it is a sign of a healthy natural environment. But that charity warned that half of Britain’s butterfly species are either already threatened, or close to being threatened with extinction.

Butterfly Conservation's senior surveys officer Dr Zoë Randle said this was "a vital year" for the survey, with last year’s record temperatures, heatwave and drought killing off many of the plants that caterpillars needed to eat.

"We know that the previous extreme summer droughts in 1976 and 1995 took a heavy toll on butterflies and numbers crashed the following year, taking almost a decade to recover," she said. “The data collected during this year’s Big Butterfly Count will give us a valuable insight into what the effect of the most recent extreme weather has been, and how we might be able to better protect our beautiful butterflies."

Dr Randle added: "With climate change here to stay, we need people to take part more than ever before.”

Last year almost 100,000 Counts took place up and down the UK, with participants spending a combined two-and-a-half years worth of time counting butterflies in their gardens, local parks and in the countryside, Butterfly Conservation said. The information gathered will help to inform conservation projects and government policies, and supports scientists and other experts with their research.

“We know 80% of butterflies in the UK have declined since the 1970s, which means there are fewer butterflies to be seen than in years gone by," Dr Randle said. "However, even if you don’t see any butterflies during your count, we still want you to tell us."

The charity needed to know where there were not any butterflies, just as much as it needed to know where there were, she said. "So please still log your result and then pick another day or location and try again. There are no limits on how many times you can take part.”

How to take part in the Big Butterfly Count:

Butterfly Conservation’s Big Butterfly Count is the largest citizen-science project of its kind, and everyone can help collect important scientific data which could help inform conservation decisions in the future.

The count can be done with alone or with family and friends, and takes just 15 minutes. It is open to anyone in any part of the UK - whether they live in towns, cities or the countryside.

Unless you're a butterfly expert, you can print out a butterfly ID chart or download the free app from the Big Butterfly Count website.

Then you have to select a place to do your count. Butterfly Conservation says no green space is too small - you can do it in your back garden, on a small terrace or balcony with some pot plants, in a public park, or a country lane.

The next step involves keeping an eye out for any butterflies - or even daytime moths - in your chosen spot for 15 minutes, making sure to record what time you start and finish. Keep track of what kinds of butterflies you see, and how many of them there are - even if you don't see any at all.

Then you should submit your findings via the website or app. This will also let you check out Butterfly Conservation's interactive map - to see which species have been recorded in different parts of the country.