One butterfly, two butterflies…


Wildlife enthusiasts across England are being encouraged to record the sightings of butterflies – and some species of moths – as part of the world’s biggest annual survey of the increasingly threatened insects.

The British “Big Butterfly Count” – which this year runs from July 14 to August 6 – helps conservationists take stock of the health of the country’s natural environment, amid mounting evidence that it is in ever greater danger.

Volunteers download a chart that helps them identify the different species and then record the insects they observe in gardens, parks, or anywhere else, online on the chart.

The survey comes as experts warn that the often brightly colored insects’ numbers in England are plummeting as they struggle to survive due to unprecedented levels of environmental change.

“It is a worrying picture,” says Richard Fox, head of science at the butterfly conservation organization under whose guidance the survey is being carried out.

“The biggest causes of the decline are due to what we as humans have done over the past 50, 60, 70 years,” he says at Orley Common, a giant park in Devon, in the south-west of England. Even in this park there are fewer and fewer butterflies, even if it offers the ideal habitat for them.

A report released earlier this year, which Fox helped compile, uses 23 million data inputs and shows that four out of five butterflies in England’s population numbers have declined since the 1970s.

According to a conservation red list, half of the country’s 58 species are indicated as threatened.

‘Citizen Scientists’

England is one of the countries where natural resources have been most depleted and almost half of its biodiversity has been lost over the past decades, according to a report from the British Parliament that was published in 2021.

Agriculture, the use of insecticides and fertilisers, together with changes to the natural landscape to make more land available for farming, is partly to blame for this.

Meanwhile, the counting of butterflies, some of the most closely watched insects in the world, has helped to at least slightly stem the decline.

Volunteers have been helping to count the insects since the 1970s and participation in the survey is becoming more and more popular, mainly thanks to new technology being used for it.

The Big Butterfly Count was first launched in 2010 and bills itself as the world’s largest survey of its kind.

More than 64,000 citizen “scientists” participated last year and reported a total of 96,257 sightings of butterflies and certain moth species. Butterfly Conservation and the British Center for Ecology and Hydrology have also developed an iRecord Butterflies app to identify the species and accurately record the location of sightings. Almost a million observations have been recorded in this way since 2014.

Butterflies help to indicate the health of an ecosystem because the insects respond quickly to environmental changes and are considered a kind of early warning system for other wildlife losses, according to conservation experts.

“One of the great things about butterflies and this fantastic data we have on them is that they function as indicator species for all other groups,” says Fox.

“We know a little about how bees do, and we know a little about how bugs, beetles, flies, wasps and other important insects do.”