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Butterfly numbers increase this year but decrease long term, figures show

It has been a bumper year for butterflies in 2023 with more counted than in the last four years, although figures show a significant decrease in the long term, according to conservationists.

Participants in the Big Butterfly Count recorded more than 1.5 million butterflies and day-flying moths between July 14 and August 6.

It is thought they benefited from the wetter weather, with 12 butterflies recorded on average per count, compared to nine in last year’s long periods of drought and heat.

The most-seen species – for the first time – was the red admiral with 248,077 recorded, as climate change means it is growing in prevalence in the UK.

Holly blue
Holly blue numbers have increased from last year and over the long term (Iain H Leach/Butterfly Conservation/PA)

Gatekeeper was next with 222,896 sightings – an increase of 12% on last year, but long-term figures show a decrease of 28% since 2010.

White butterflies came third and fourth, with large whites recorded 216,666 times and small whites seen 190,506 times – an increase of 11% and 15% on last year respectively.

Holly blue numbers also saw a 66% increase on 2022, with a long term trend showing an increase of 41%.

Dr Zoe Randle, senior surveys officer at Butterfly Conservation said: “The mixed weather this year has helped as there has been an abundance of green food plants available for caterpillars and plenty of nectar-rich flowers for adult butterflies.

Green-veined white
Green-veined white has seen the biggest drop in numbers since the Big Butterfly Count started 13 years ago (David Dennis/Butterfly Conservation/PA)

“However, while the number of butterflies recorded this summer has been the highest since 2019, the longer-term trends show worrying declines for some of the UK’s most common butterfly species.”

Species that have declined since last year and over the long term include ringlet, common blue and speckled wood.

Green-veined white has seen the most severe drop in numbers since 2010 with a decrease of 61%, while there was little change on last year.

Dr Richard Fox, head of science at Butterfly Conservation, said: “One of the biggest threats butterflies in the UK face is habitat loss.

Ringlet
Ringlet has also seen a decline, with conservationists encouraging people to grow more nectar-rich plants to help them (Bob Eade/Butterfly Conservation/PA)

“While the weather certainly has an impact on numbers from year to year, butterflies, moths and many other species can generally cope with variable weather. What they can’t cope with is habitat destruction.

“Butterflies need a place to live. If they can feed, breed and shelter, they can thrive.

“By creating a wild space in your outdoor area you can help to reverse the massive losses of wildlife-friendly habitat and start to turn around the fortunes of our declining butterflies.”

A wild space can be created anywhere, the conservationists said. It could mean leaving a patch of long grass in the garden or planting a small selection of nectar-rich plants on a balcony.