Big Butterfly Count 2021 sees lowest ever number of butterflies recorded in Scotland

Wildlife charity warns that we must act now if we are to save Scotland’s butterflies and moths for future generations

Butterfly Conservation has today released data on the number of butterflies and day-flying moths counted across the UK in this year’s Big Butterfly Count, which ran from 16^th July – 8^th August.

Worryingly, the decline in the number of butterflies and moths across the UK is continuing, with the overall number of butterflies recorded per count at its lowest level since the Big Butterfly Count began 12 years ago.

The nation’s love of butterflies isn’t diminishing. Despite the low butterfly numbers, and relatively poor weather, more butterfly counts were submitted in Scotland than ever before. 5,420 butterfly counts were submitted by 4,005 people, an increase of 35% and 14% respectively on 2020 figures.

Dr Zoë Randle, Senior Surveys Officer at Butterfly Conservation said: “This year’s results show that the average number of butterflies and moths per count is the lowest we’ve recorded so far, and the average number in Scotland was down by 7% on 2020 figures.

“More counts are undertaken and submitted year on year, but it seems that there are fewer butterflies and moths around to be counted.”

Some of the UK’s most-loved species including the Small Tortoiseshell and Peacock butterflies dropped in numbers this summer. This was a situation repeated across the UK, with the iconic Peacock butterfly suffering its lowest numbers since 2012. The Small Tortoiseshell, once a frequent visitor to gardens in the UK, had its third worst summer in the history of the Big Butterfly Count and shows a significant long-term decline in Britain.

Some species did show an increase on 2020 figures, including the Ringlet (above), which appeared to bounce back from low numbers during last year’s Big Butterfly Count. However, scientists at Butterfly Conservation warn that last year’s unusually sunny spring allowed them to emerge earlier, and that 2021’s results are therefore more typical for these species.

The greatest single species increase seen in Scotland was that for the Holly Blue, which is at complete odds with the general pattern in the UK, where the number of Holly Blue butterflies counted dropped. The Holly Blue has recently colonised Scotland and is a species to watch in future years to see if it expands across Scotland.

The Scotch Argus was included in the target species list for the Big Butterfly Count this year, and a total of 2,305 were seen, with 50% of these in the Highlands.

The weather across the UK this year has had a significant impact on butterfly and moth species, and with more climate change related extreme weather events likely, the impact on some of the UK’s most loved insects could be devastating.

Dr Randle explains: “Some of the UK’s butterflies have more than one generation per year, meaning we would see adult butterflies in spring and summer. The majority of these double-brooded species experienced their worst year since the start of the Big Butterfly Count in 2010.

“Weather changes are likely to be the cause of this. March 2021 was warmer than average which would have stimulated butterfly activity. However, May was very wet which will have hampered butterfly feeding and breeding. These combined weather effects are likely to have reduced the spring generation which has knock-on effects for the second generation in the summer.”

Butterflies and moths are important indicators of the health of the environment, and a decline in abundance is a serious cause for concern.

Butterfly Conservation has launched an ambitious strategy to help address the problems for butterflies and moths and be part of nature’s recovery.

Julie Williams, CEO of Butterfly Conservation, says: “The facts are clear. Nature is in crisis and we need urgent action, not just to prevent further species losses but to rebuild biodiversity.

“Since 1976, 76% of butterflies have declined in abundance or distribution, and the downward trend continues. We have come to accept that encounters with butterflies, moths and other wildlife are unusual, delightful but infrequent.

“It doesn’t have to be this way and through our new strategy Butterfly Conservation is pledging to halve the number of threatened butterfly and moth species in the UK, double our impact on landscape restoration, and galvanise thousands of people to create new wild spaces for nature.

“We can’t do this alone though and are urging people to join us to create a world where butterflies and moths thrive and can be enjoyed by everyone, everywhere.”

To find out more visit www.butterfly-conservation.org

SPECIES RESULTS IN SCOTLAND – BIG BUTTERFLY COUNT 2021

	Big Butterfly Count 2021SCOTLAND	Abundance	Ave per count	% change from 2020
1	Small White	5,042	1.09	8%
2	Ringlet	4,252	0.92	53%
3	Meadow Brown	4,252	0.88	38%
4	Large White	4,099	0.88	32%
5	Scotch Argus	2,305	0.50	n/a
6	Green-veined White	1,966	0.42	-10%
7	Small Tortoiseshell	1,672	0.36	-70%
8	Speckled Wood	943	0.20	2%
9	Common Blue	845	0.18	-13%
10	Red Admiral	685	0.15	-62%
11	Peacock	574	0.12	-80%
12	Six-spot Burnet	543	0.12	-47%
13	Small Copper	367	0.08	-12%
14	Painted Lady	248	0.05	-11%
15	Holly Blue	153	0.03	230%
16	Silver Y	113	0.02	-19%
17	Comma	86	0.02	-54%
	TOTAL	27,997	6.03	-7%

SPECIES RESULTS IN THE UK – BIG BUTTERFLY COUNT 2021

	Big Butterfly Count 2021UK	Abundance	Ave per count	% change from 2020
1	Small White	252,151	1.88	-5%
2	Large White	229,218	1.71	-16%
3	Meadow Brown	197,060	1.47	33%
4	Gatekeeper	133,726	0.99	-30%
5	Red Admiral	75,394	0.56	-10%
6	Ringlet	63,311	0.47	81%
7	Peacock	61,668	0.46	-63%
8	Small Tortoiseshell	38,543	0.29	-32%
9	Marbled White	28,704	0.21	213%
10	Green-veined White	27,784	0.21	-9%
11	Small Copper	22,897	0.17	11%
12	Comma	21,320	0.16	-32%
13	Speckled Wood	18,086	0.13	-41%
14	Six-spot Burnet	15,964	0.12	42%
15	Common Blue	14,376	0.11	-59%
16	Painted Lady	12,180	0.09	44%
17	Holly Blue	10,018	0.07	-58%
18	Brimstone	7,984	0.06	-33%
19	Silver Y	3,661	0.03	53%
20	Scotch Argus	2,326	0.02	n/a
21	Jersey Tiger	2,034	0.02	n/a
	TOTAL	1,238,405	9.21	-14%