big butterfly count 2017 results

The curse of the UK summer holiday weather struck big butterfly count 2017. For butterflies and butterfly counters, July and August were dominated by unsettled weather and above average rainfall. Overall it was one of the wettest UK summers for 100 years. And this after six months (January-June) of above average monthly temperatures, which encouraged butterflies to emerge earlier than usual.

The combined impacts of this topsy-turvy weather were to reduce the numbers of butterflies seen during big butterfly count 2017, both because the abundance of some species was reduced by the summer weather and because others had come out early and were already past their peak numbers when the count started.

Despite an amazing 550,000 individual insects of the 20 target species being spotted during big butterfly count 2017, the average number of individuals seen per 15 minute count was the lowest recorded since the project began in 2010! A mere 10.9 individuals per count were recorded, down from 12.2 in 2016. Indeed the average number of individual butterflies per count has decrease in each year of big butterfly count since 2013, when over twice as many butterflies were seen per count compared with 2017.

Record-breaking Count

While the butterflies may have been relatively scarce, there was no shortage of participants for the world's largest count of butterflies. Altogether, 62,547 counts were submitted by over 60,400 participants, a 64% increase in the number of counts and a 66% increase in the number of people taking part compared with 2016. This made big butterfly count 2017 by far the most successful yet (the previous record was of 50,030 counts in 2015). An amazing effort by participants from Shetland to Sussex, Lincolnshire to Londonderry - many thanks to all of you!

In total almost 310,000 counts have been undertaken since big butterfly count started in 2010. That equates to 4.6 million minutes spotting species and helping to assess the state of our environment. And the data gathered by this army of citizen scientists are proving really useful. Recent research led by Butterfly Conservation and Kent University shows that changes in butterfly populations estimated from big butterfly count data match closely with those from much more intensive, transect-style butterfly monitoring. This raises the potential for big butterfly count data to be used alongside more rigorous schemes in assessing the changing fortunes of widespread butterflies, particularly in urban areas and private gardens, both of which are very well recorded in big butterfly count.  

Flying high

One of the stars of the summer was the Red Admiral. After a good year in 2016, numbers of this powerful, migratory butterfly soared during 2017, recording its best ever big butterfly count performance (the only target species to achieve a new best in 2017). Numbers of Red Admirals were up 75% compared with the 2016 Count and threefold compared with 2015. Its success wasn’t restricted to the south either, Red Admiral did well in Scotland and Northern Ireland in 2017 (country-level results).

Another winner was the Comma, which profited from the warm spring by producing a bumper summer generation of the brighter-orange hutchinsoni form that breeds immediately rather than going into hibernation. It bounced back strongly (up by 90%) from a relatively poor year in 2016, recording its second best big butterfly count ever.

There was more good news among the ‘blues’. Common Blue and Small Copper, both of which did terribly during big butterfly count 2016, increased strongly, up 109% and 62% respectively, although their populations weren’t particularly large compared with some other previous years.

The Gatekeeper was another species that did very badly in 2016, but which showed a good improvement in big butterfly count 2017, up 24% year on year. Indeed, it topped the big butterfly count chart for the third time in 2017.  

Woeful whites

It wasn’t all good news though. The three common ‘whites’ all decreased compared with 2016 and seemed thin on the ground. The Green-veined White, which was down 38% on 2016, recorded its lowest abundance in the eight years of big butterfly count. Both the Large White and Small White suffered their second worst big butterfly count performances, and numbers dropped by 38% and 37% respectively compared with 2016. Interestingly, this did not appear to be the case in Northern Ireland, where counts of both Large and Small Whites increased substantially on 2016.

There was no good news for the Small Tortoiseshell, which has been the source of much concern over the past decade or so, or the beautiful Peacock, both of which remained at low levels, very similar to those recorded during big butterfly count 2016.

Early emergers 

The fortunes of other target species that appeared to fare badly in big butterfly count 2017 need to be considered carefully. The three biggest recorded year-on-year declines, Marbled White, Large Skipper and Ringlet, all emerged early this year in response to the warm winter and spring. As a result, the peak in their numbers occurred two weeks earlier than in 2016 and happened before big butterfly count 2017 had started. Thus, 2017 counts of these species appeared lower than in 2016, not because the butterfly’s had declined in overall population but simply that the majority of individuals had already flown and lived out their short lives before the counts took place. This was also the case with the Meadow Brown, but caused less of an impact on the results because its flight period is very much longer than that of these other species.

 This type of issue is inevitable for a short, ‘snap-shot’ survey like big butterfly count, but does not lessen the importance of the event. Butterfly Conservation scientists have shown that such effects can be corrected retrospectively to ensure that big butterfly count data can make a meaningful, long-term contribution to assessing the state of the UK’s common butterflies.

Species results 2017

The Gatekeeper secured the top position in the big butterfly count 2017 chart. This is the third time that it has been the most abundant big butterfly count species (it was also top in 2011 and 2015), more than any other species. The Red Admiral achieved its highest ever placing of 2nd (previous best was 5th in 2011), as did the Comma in 7th place (its previous best was 9th in 2015). A poor year for the Large White and Small White saw them drop from 1st and 2nd places in 2016 to 5th and 4th (respectively). The Meadow Brown took the 3rd spot for the third year running. At 12th in the big butterfly count 2017 chart, the Green-veined White slumped to its lowest ever placing.

The 2017 results for all 20 of the big butterfly count target butterfly and moth species are shown below:



% change from 2016






Red Admiral




Meadow Brown




Small White




Large White












Small Tortoiseshell




Common Blue




Speckled Wood








Green-veined White




Six-spot Burnet




Painted Lady




Large Skipper




Holly Blue




Small Copper








Marbled White




Silver Y



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. With your help, we can make it even bigger and better in 2018.

What you said about big butterfly count 2017

big butterfly count is not just about gathering valuable information about how our common species are faring, it’s also fun and introduces butterflies and butterfly recording to new audiences. Here's what some of the 2017 participants had to say about big butterfly count:

"I think it's fantastic! And such a great way to involve and inspire ordinary (non-scientific!) people of all ages...Thank you!" Ms. Souter, Moray

"I took part in this with my mum on the school holidays. I am 8 and am really interested in butterflies." Ms. Foster, Leicestershire

"Enjoyed standing observing for 15 mins although dog a little puzzled." Ms. Hanson, Anglesey

"Really concerned by the lack of many species of butterfly in wild flower meadows I manage and gardens I have built this season." Mr. Norman, Essex

"It got my 8 & 5 year old interested in nature yet helping Butterfly Conversation at the same time! Great activity!" Ms. Craig, Co. Londonderry

"Really useful chart. I have learned a lot. " Ms. Makin, Pembrokeshire

"I am really concerned about the declining butterfly and bee populations and thought this would be helpful. I had a great time trying to identify the different types and 15 minutes is an easy amount of time to spend - I just did it whilst out with the dogs!" Ms. Chamberlain, Borders

"I'm learning so much by participating. A wonderful project !" Ms. Haines, Hampshire

"It was a great reason to get out on a sunny day - awesome butterflies" Mr. Goldsmith, Wiltshire

"We have been learning about minibeasts so this was a great activity for the class to take part in, we really enjoyed counting the butterflies around the school grounds." Ms. Trimby, Yorkshire

View Big Butterfly Count website