Big Butterfly Count 2019 Results

A huge thank you to everyone who took part in the 10th big butterfly count. Thanks to you, all 113,502 of you, it was the biggest yet, and over 100,000 counts (116,009 to be exact) were undertaken for the first time in big butterfly count history. That's 29,000 hours of enjoying our native butterflies and moths, relaxing from the stresses of modern life and gathering useful data both to assess and protect nature.

Almost 1.6 million individuals of the 19 target species (17 butterflies and two day-flying moths) were totted up during the official big butterfly count period of 19 July - 11 August 2019. Generally, people saw more butterflies than in 2018 - on average, participants recorded just over 16 individuals of the target species per 15-minute count, the second highest average since big butterfly count began in 2010 and well above the 11 per count seen in 2018. If the abundant Painted Lady butterflies (of which more below) are excluded from the totals, people still saw more butterflies per count compared to the previous year, although not by much. This suggests that with a few notable exceptions, the summer of 2019 was not exceptional for the UK's common butterflies.

In the 10 years of big butterfly count so far, 522,000 counts have been undertaken, logging 6.2 million butterflies and moths - an amazing achievement.

Painted Lady

The incredible inter-continental migrant, the Painted Lady had an excellent year and was the stand-out winner of big butterfly count 2019. Every year, successive generations of Painted Ladies spread northwards from Africa, crossing the Sahara Desert and then the Mediterranean Sea to breed in central and northern Europe during the summer, with their offspring making return journeys southwards to avoid the winter cold - a round trip of some 7,000 miles. The number that reach our shores varies greatly from year to year, with periodic years of great abundance termed "Painted Lady Years". This natural phenomenon last occurred in the UK in 2009 (and prior to that in 2003 and 1996).

2019 has turned out to be a Painted Lady Year. Large numbers arrived in mid- and late June, laying eggs and producing a new 'home-grown' generation of butterflies that emerged during big butterfly count. In addition, at the end of July/start of August, when the Count was well underway, enormous numbers of Painted Ladies arrived on the coast of eastern Scotland and north-east England, producing spectacular scenes of clouds of butterflies for local observers. The arrival of these immigrant insects, probably heading south from Scandinavia, can clearly be seen in the map of total Painted Lady numbers recorded during big butterfly count 2019 (below). Having reached the east coast of Britain, the butterflies then spread inland, as shown by the high numbers seen throughout the Central Belt of Scotland and in North West England and North Wales.

Painted Lady came top overall in big butterfly count 2019, and was also the most numerous species recorded in each of England, Northern Ireland, Scotland and Wales. Its previous best performance in the Count was coming 13th in 2018 and it is typically one of the least frequently seen of the 19 target species. Some 420,000 Painted Ladies were counted, making up over one quarter of all the butterflies in the 2019 event and more than twice as many as the next most abundant species (the Peacock).

Buddleia bonanza

Britain's Buddleia bushes welcomed much better numbers of colourful butterflies during the summer of 2019. The Peacock enjoyed its best summer since 2014, coming second overall and with numbers up 235% on last year's count. Red Admiral bounced back strongly after a disappointing 2018, with numbers up by 138%, and even the beleaguered Small Tortoiseshell, which has lost three-quarters of its UK population since the 1970s, fared (relatively) well. It had its best big butterfly count result since 2014 and numbers were up 167% on 2018.

Other winners, compared with 2018, included the Marbled White (up 264%), Gatekeeper (up 95%), Meadow Brown (up 87%) and Six-spot Burnet (up 64%).

Whites on the wane

The three common white butterflies, Large White, Small White, and Green-veined White, all of which did extremely well in big butterfly count 2018, each suffered a large drop in numbers. Bizarrely, each declined by 42% compared with the same period last year.

Both of the blue butterflies included in big butterfly count also decreased. Hopes were high for the Holly Blue, which had its best ever Count result in 2018 and had a strong spring generation earlier in 2019, but numbers of the summer brood were very disappointing (down 54% on 2018). Similarly, the Common Blue, which fared well in 2018, saw its populations drop back, with counts down 59%.

Unfortunately, all five of these 2019 'losers' were seen at levels well below their average per count over the whole 10 years of big butterfly count.

The 2019 results for all 19 of the big butterfly count target butterfly and moth species are shown below:

Species results

The Top 10 species for England, Northern Ireland, Scotland and Wales can be found here.

The big butterfly count will return again next summer to enable us to identify longer term trends in our butterfly species.

Thank you once again for taking part in this year’s big butterfly count, the biggest butterfly event of its kind in the world and enabling us to assess how butterflies and moths have fared this summer. Make sure you and your friends and family take part in big butterfly count 2020.

See results for your country

View Big Butterfly Count website