Number of butterflies in UK falls to lowest since surveys began

Prevalence of plastic grass and rising levels of nitrates blamed for absence of many species in urban gardens

Despite a summer of glorious sunshine, fewer butterflies than ever were recorded in the world’s largest citizen science insect count.

On average, fewer than nine butterflies per count were spotted in this summer’s Big Butterfly Count, the lowest in the 13 years of Butterfly Conservation’s popular July recording scheme.

It is the third year in a row that the count has recorded its lowest-ever average abundance, a worrying sign that once-common flying insects are continuing to disappear from Britain.

Zoe Randle, senior surveys officer for Butterfly Conservation, said: “It is really quite worrying, particularly because we had such good weather this summer across most of the UK, with above-average temperatures and below-average rainfall, particularly in July. We need to do a lot more to protect and restore habitats for these widespread species.”

The gatekeeper, a butterfly of country hedgerows and grass verges, was the most common butterfly with 142,618 counted, up 58.6% on summer 2021, which was its second worst Big Butterfly Count result.

But there were 161,987 gatekeepers counted in 2019, and yet it was only the fourth most common butterfly that year.

The next five most counted species in this year’s survey – large and small white, meadow brown, red admiral and peacock – all declined on the levels recorded last year, which was the worst year since records began.

The only bright spots this summer were large rises for common blues (up 154.4% on last year), holly blues (up 119.8%), speckled woods (up 97.5%) and commas (up 94.7%).

The fine weather did cause many butterflies to emerge a week or two earlier than normal and so the Big Butterfly Count – which starts in the third week of July – missed the peak emergence of some common midsummer species, such as the meadow brown and marbled white.

But Randle said that even allowing for the earlier emergence of species, it was a disappointing result.

Lepidopterists, specialists in butterflies and moths, are also concerned that the drought this summer could affect next year’s numbers, particularly butterflies such as the ringlet, whose caterpillars feed on grasses in late summer. “Egg-laying females might not have found anything suitable to lay their eggs on because their food plants were dry and desiccated,” said Randle.

The drought of 1976 proved disastrous for many species, but the more recent drought in 2018 did not appear to have the negative impact that butterfly scientists feared it might.

More than three-quarters of the Big Butterfly Count’s recordings were undertaken in people’s gardens. The declines support other scientific studies showing that butterflies are disappearing more quickly in urban areas than in the countryside.

Randle said that factors in the loss of butterflies in towns and cities include the popularity of plastic grass, the paving over of front gardens for parking spaces, “garden grabbing” by developers and rising levels of nitrates from traffic, which affect butterflies’ food plants.

One piece of good news was the widespread appearance this summer of a day-flying moth, the Jersey tiger, which appears to be thriving in the changing climate and breeds in gardens. Its numbers rose by 136.5%.

Randle said that while the news was “depressing”, people could do something about it, by practising wildlife-friendly gardening, keeping long-grass areas in gardens, allotments and parks, and planting specific plants for some species, such as alder buckthorn, which is the food plant for the brimstone butterfly.

The 10 most commonly spotted butterflies in 2022

  1. Gatekeeper (+58.6% compared with 2021)

  2. Large White (-9.4%)

  3. Small White (-25.8%)

  4. Meadow Brown (-17.5%)

  5. Red Admiral (-20%)

  6. Peacock (-5.5%)

  7. Small Tortoiseshell (+13%)

  8. Comma (+94.7%)

  9. Ringlet (-38.5%)

  10. Common Blue (+154.4%)

Contributor

Patrick Barkham

The GuardianTramp

Related Content

Article image
Rare UK butterflies enjoy best year since monitoring began
Hot summer of 2018 boosted large blue, and black hairstreak, but small tortoiseshell declined

Patrick Barkham

08, Apr, 2019 @5:30 AM

Article image
Record low number of British butterflies baffles scientists
Annual Big Butterfly Count shows big falls in peacocks and small tortoiseshells

Patrick Barkham

28, Sep, 2020 @5:22 AM

Article image
Record low number of British butterflies a 'shock and a mystery'
Annual Big Butterfly Count records lowest ever number of usually prolific species despite the relatively warm, dry summer

Patrick Barkham

10, Oct, 2016 @7:36 AM

Article image
Britain’s butterflies bolstered by conservation efforts
Heath fritillary among species helped by habitat restoration – but concerns over future remain

Damian Carrington Environment editor

30, Mar, 2022 @5:00 AM

Article image
Scotland’s butterflies flourishing in hotter summers
Several species including red admiral show marked increase but climate crisis poses long-term threat

Libby Brooks Scotland correspondent

19, Aug, 2022 @12:08 PM

Article image
British butterflies suffered seventh worst year on record in 2017
Annual monitoring shows many native species suffered further falls, and two declining species had their worst seasons on record

Patrick Barkham

11, Apr, 2018 @5:30 AM

Article image
2016 could be worst year on record for British butterflies, experts warn
Public asked to take part in annual count to assess the impact of a sunless summer, cool spring and mild winter on butterfly numbers

Patrick Barkham

15, Jul, 2016 @5:01 AM

Article image
UK butterflies vanish from nearly half of the places they once flew – study
Butterfly Conservation report reveals 42% decline in distribution of 58 native species since 1976

Patrick Barkham

03, Feb, 2023 @6:00 AM

Article image
Number of butterflies in the UK at a record low, survey finds
Experts say results of Butterfly Conservation’s latest survey signal that nature is ‘in crisis’

Miranda Bryant

07, Oct, 2021 @5:01 AM

Article image
Meadow brown butterflies ‘adapt’ to global heating by developing fewer spots
Study finds female chrysalises that develop at higher temperatures have fewer eyespots, making them harder to see in dry grass

Patrick Barkham

18, Jan, 2024 @5:00 AM