Wider Countryside Butterfly Survey (WCBS)


The WCBS was established in 2009 to improve data on the national population status of widespread butterflies across the countryside as a whole. This is important given that most site-based monitoring is biased towards good quality semi-natural habitat relatively rich in butterflies. The WCBS is based on the British Trust for Ornithology (BTO)’s Breeding Bird Survey (the ‘BBS’), counting along two parallel 1km long transects subdivided into 10 sections, located within randomly selected 1km squares throughout the UK.

Unlike for the standard Butterfly Monitoring Scheme transects, only 2 to 4 visits are required for WCBS squares with a minimum of 2 visits in July/August and other visits, particularly earlier in the year for spring species such as Orange-tip and the first broods of bi/multi-voltine species, encouraged.

The survey is co-ordinated centrally by Butterfly Conservation but with the help of a WCBS Champion in each Branch.


With your help, we aim to resurvey all the squares covered the previous year and more.  Many thanks to everyone who is currently surveying a square. 

The good news is that following an article & map in our branch magazine (Arion, issue 115), we now have volunteers interested in surveying another 10 WCBS squares - thankyou.


If you would like further information about the WCBS survey or would like to take on one of the available squares in Somerset or Bristol (for summer 2021) please contact Penny, our Branch WCBS Champion  (click to send email).

A copy of the WCBS recording form is available from here or on the WCBS page of the UKBMS website.

WCBS map July 2020