Numbers of top five species up on last year while small tortoiseshell moves north

It has been a painted lady summer. Nearly half a million of the migratory creatures were counted in British parks and gardens as part of the biggest butterfly survey in the world.

The painted lady topped the charts of the annual Big Butterfly Count with 420,841 recorded during high summer after their first big influx on British shores in a decade.

This year too there were greater numbers of common species than last year – 1.1 million of the most common five species combined were seen, compared with 660,000 in 2018.

There were big increases for peacocks (207,814), gatekeepers (161,987) and red admirals (91,146), while the number of marbled whites increased by 264% as global heating helped the butterfly move north through Britain.

The count also revealed that global heating could be the cause of the mysterious decline of the once ubiquitous small tortoiseshell butterfly, whose numbers have fallen by 78% since the 1970s. Last summer was the worst for the species since the count began but this year it bounced back: 70,000 were spotted, up 167% and bringing its highest number for five years.

Richard Fox, of Butterfly Conservation, which organised the survey, said the small tortoiseshell showed up well in Scotland and Northern Ireland, where it was the second most seen species, but struggled to make the top 10 in England and Wales. On average, count participants in Scotland and Northern Ireland saw more than twice as many small tortoiseshells as people in England.

“We’re still trying to establish what is behind the long-term decline of the small tortoiseshell and while it is good news that the butterfly fared better this summer, the poor results in southern England in particular suggest that climate change may be having more of an impact on this species than we have previously realised,” Fox said.

A record 113,500 people took part in this year’s count, spotting nearly 1.6m butterflies during the three-week recording period from the end of July.

Numbers of common white species and blue butterflies slumped compared with last summer. The large white, small white, and green-veined white, fell by a combined 42%, the common blue was down 59% and the holly blue fell 54%.

Big Butterfly Count 2019 – top 10 species seen

1. Painted lady (420,841)

2. Peacock (207,814)

3. Small white (179,715)

4. Gatekeeper (161,987)

5. Large white (138,671)

6. Meadow brown (110,858)

7. Red admiral (91,146)

8. Small tortoiseshell (70,704)

9. Speckled wood (33,015)

10. Green-veined white (32,965)