Skip to content
Butterfly Conservation has today (07 October) released data on the number of butterflies and day-flying moths counted across the UK in this year’s Big Butterfly Count, which ran from 16 July – 08 August.
Worryingly, the decline in the number of butterflies and moths across the UK is continuing, with the overall number of butterflies recorded per count at its lowest level since the Big Butterfly Count began 12 years ago.
The nation’s love of butterflies isn’t diminishing. Despite the low butterfly numbers, and relatively poor weather, more butterfly counts were submitted than ever before.
Over 150,000 counts were registered, representing more than 38,000 hours of butterfly counting in gardens, parks and the countryside.
‘This year’s results show that the average number of butterflies and moths per count is the lowest we’ve recorded so far. On average people counted nine butterflies or moths per count, which is down from 11 in 2020, and down again from 16 in 2019. More counts are undertaken and submitted year on year, but it seems that there are fewer butterflies and moths around to be counted.’
DR ZOË RANDLE
Senior surveys officer at Butterfly Conservation
Some of the UK’s most-loved species, including the small tortoiseshell and peacock butterflies, dropped in numbers this summer.
The iconic peacock butterfly suffered its lowest numbers since 2012. The small tortoiseshell, once a frequent visitor to gardens in the UK, had its third-worst summer in the history of the Big Butterfly Count and shows a significant long-term decline in Britain.
It wasn’t bad news for all species, with some – including the marbled white and ringlet – appearing to bounce back from their low numbers during last year’s Big Butterfly Count.
However, scientists at Butterfly Conservation warn that last year’s unusually sunny spring allowed them to emerge earlier, and that 2021’s results are therefore more typical for these species.
This year’s weather has had a significant impact on butterfly and moth species, and with more climate change related extreme weather events likely, the impact on some of the UK’s most loved insects could be devastating.
‘Some of the UK’s butterflies have more than one generation per year, meaning we would see adult butterflies in spring and summer. The majority of these double-brooded species experienced their worst year since the start of the Big Butterfly Count in 2010. Weather changes are likely to be the cause of this.
‘March 2021 was warmer than average which would have stimulated butterfly activity. However, May was very wet which will have hampered butterfly feeding and breeding. These combined weather effects are likely to have reduced the spring generation which has knock-on effects for the second generation in the summer.’
DR ZOË RANDLE
Senior surveys officer at Butterfly Conservation
Butterflies and moths are important indicators of the health of the environment, and a decline in abundance is a serious cause for concern.
Butterfly Conservation has launched an ambitious strategy to help address the problems for butterflies and moths and be part of nature’s recovery.
‘The facts are clear. Nature is in crisis and we need urgent action, not just to prevent further species losses but to rebuild biodiversity.
‘Since 1976, 76% of butterflies have declined in abundance or distribution, and the downward trend continues. We have come to accept that encounters with butterflies, moths and other wildlife are unusual, delightful but infrequent. It doesn’t have to be this way and through our new strategy Butterfly Conservation is pledging to halve the number of threatened butterfly and moth species in the UK, double our impact on landscape restoration, and galvanise thousands of people to create new wild spaces for nature.
‘We can’t do this alone though and are urging people to join us to create a world where butterflies and moths thrive and can be enjoyed by everyone, everywhere.’
JULIE WILLIAMS
CEO of Butterfly Conservation
2020 hailed a good year for butterflies – but conservation scientists warn that our view of what is ‘good’ might be shifting.
Helping our butterflies helps our own mental health, says Dr Amir Khan.
Subscribe to our newsletter
Weekly ethical news, offers, comps and a free digital mag (quarterly) – what’s not to love?
