Wider Countryside Butterfly Survey

Small Tortoiseshell by John Harding

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 UK Butterfly Monitoring Scheme (UKBMS) 2021 Official Statistic has been released on the UKBMS website. The Official Statistic describes the trends of 56 UK butterfly species based on the results of the UKBMS, including data from the WCBS. Butterfly populations fluctuate naturally, but the long-term data-set - with records beginning in 1976 - allows us to see trends over decades and reveal a steady decline in most of the UK's butterflies. While weather conditions in Spring likely contribute to the annual fluctuations we see in butterfly numbers, long-term trends are in many cases driven by human activity, particularly the degradation of vital habitat, and the impact of climate change.

The latest results show that 2021 was a poor year for butterflies, with widespread and common species suffering due to the cold, wet Spring. The Green-veined White had its fourth-worst year on record and Large Skipper its fifth-worst. The Common Blue, Large White, and Small Skipper were also recorded in very low numbers and even species that show long-term increases, such as the Ringlet, had their worst season for many years. The White Admiral, in particular, had an exceptionally poor year, with its third-worst year since 1976. Pearl-bordered and Small Pearl-bordered Fritillary were also recorded at levels well below their long-term averages.

However, the statistics show good news for other threatened butterflies, such as the Heath Fritillary, which has increased by 112% in the last ten years, and the Silver-studded Blue, which had its best year since 1996 and shows an increase of 70% since the 1970s. These species have been the focus of targeted conservation measures; in the context of declines in butterflies across the UK, this shows that effective conservation can be successful, supporting butterflies even in years with poor weather conditions like 2021.

Like 2020, 2021 was a challenging year for data collection due to the pandemic, but 476,000 records from more than 2,900 sites were submitted to the UK Butterfly Monitoring Scheme. The data collected contribute to the conservation of the UK’s butterflies, but also paint a wider picture of the health of our natural environment, providing powerful information to drive positive change for all wildlife. BBS volunteers contribute data to this broader scheme by taking part in the Wider Countryside Butterfly Survey on their BBS survey squares. 


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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