Wider Countryside Butterfly Survey

Small Tortoiseshell by Josie Latus

The Wider Countryside Butterfly Survey (WCBS) is the main scheme for monitoring population changes of the UK's common and widespread butterflies. It is important in both assessing the changing status of widespread butterfly species and in providing an indicator of the health of the wider countryside. Data from this scheme feeds into the UK Butterfly Monitoring Scheme (UKBMS).

The UK Butterfly Monitoring Scheme is organized and funded by Butterfly Conservation, the Centre for Ecology and Hydrology, British Trust for Ornithology, and the Joint Nature Conservation Committee.  The UKBMS is indebted to all volunteers who contribute data to the scheme and we now have data from the WCBS, carried out on BBS squares spanning back to the pilot years of 2007 and 2008.

All BBS volunteers can take part in the WCBS by making extra visits to their square between May and August to count butterflies.

If you would like to get involved, all you need to get started is tell us at bbs [at] bto.org so we can allocated your BBS square for the WCBS and then either download the


instructions (PDF, 260.74 KB)

recording form

recording form (PDF, 95.12 KB)
or email bbs [at] bto.org to request a paper pack of forms. Square allocation for the WCBS on BBS squares and all WCBS data from BBS squares are entered into the UKBMS data entry system. For guidance on how to register your BBS square for the WCBS on the UKBMS website, please email bbs [at] bto.org.
Download recording forms

Entering data for the WCBS

WCBS online simple instructions for WCBS-BBS squares:

1. Register at www.ukbms.org/mydata/ (register button is at top right hand side of the screen). When choosing your username on this website, it is helpful to us if you use your BTO username.

2. Wait for us to email you to confirm that your account has been linked to your square(s). This can only be done during working hours, so please be patient.

3. Once allocated the square, log in to the UKBMS website. Hover over ‘My Data’ along the top of the page, then hover over 'Walks' and then when it appears, click on 'My Walks'

4. In the page that opens, it is crucial you change the 'Site Type' to WCBS-BBS in the drop down menu, 'Filter by site' by selecting the square you are entering data for and then find the date of your WCBS survey in the calendar and click on the little green ‘plus’ sign. You can now enter and save the datas from your visit.

Latest results

The latest results of the UK Butterfly Monitoring Scheme (UKBMS), updated with the data from 2020, are now available. The latest results show it was the third good year in a row for UK butterflies, once again the warm sunny spring weather appeared to have helped. Among the UK’s widespread butterfly species, Brimstone, Orange-tip and Marbled White all had a good year, although their numbers were not at the exceptional levels seen in 2019. After a run of four very poor years, Small Tortoiseshell numbers improved, showing an increase of 103% over 2019, but remaining below long-term average levels and the species still shows a serious (79%) decrease in abundance since 1976.

It wasn’t all good news for butterflies though and one species that had a particularly bad year was the Small Pearl-bordered Fritillary. In 2020, this butterfly experienced its third worst year on record, extending a run of nine consecutive years with below average numbers. Small Pearl-bordered Fritillary populations have declined by 68% since the UKBMS recording began in 1976. The migrant Painted Lady also had a poor year and populations of Wall, Grayling and Small Skipper all remained at a low ebb. Overall, almost half of our butterfly species (27 of 58 species) were recorded in below average numbers last year and population levels of many butterfly species continue to be down compared to 40 years ago, with just under a third (31%) of butterfly species assessed in the UK showing long-term declines.

Butterfly populations fluctuate naturally from year to year, but the long-term trends of UK butterflies are mainly driven by human activity, particularly the destruction of habitats and climate change. Conservation efforts can make a real difference to local populations and 2020 was a good year for a number of scarce species that are the targets of conservation action, including Large Blue (which had its joint second best year), Silver-spotted Skipper (which had its third best year), Silver-studded Blue (joint fourth best year) and Duke of Burgundy (joint sixth best year).

The annual changes in the abundance of 59 different butterfly species since the 1970s presented here are based on analyses of the counts undertaken every year by thousands of volunteers that participate in the scheme. In addition to counts made by Breeding Bird Survey participants and Butterfly Conservation volunteers for the Wider Countryside Butterfly Survey, these trends use information from traditional weekly butterfly transects as well as timed counts for some species.


The latest publications using WCBS data can be viewed on the BBS related reports and newsletters webpage. This includes the WCBS newsletters and the UKBMS Annual Report.

WCBS Partners

British Trust for Ornithology logo
Butterfly Conservation logo
UK Centre for Ecology & Hydrology logo
JNCC logo

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