This is a series of datasets available from the UK Butterfly Monitoring Scheme (UKBMS). The UKBMS comprises a suite of surveys carried out each year across the UK that generate data on butterfly abundance.
The UKBMS started in 1976 with 36 sites increasing to over a thousand by 2010 (although there are some data for a few sites from 1973). On the majority of sites, recorders walk a fixed route (divided into up to 15 sections) at their site every week from 1st April to 29th September each year (26 weeks), counting butterflies within defined limits (5m box) when weather meets certain criteria. On some sites different survey techniques are employed to assess the abundance of species. These techniques include timed counts and larval web surveys in fixed areas. Weather data is recorded at the time of the count and habitat data is available for most transects.
The surveys are undertaken by volunteers and other recorders, who contribute their data free of charge. The scheme is operated as a partnership between the Centre For Ecology and Hydrology (CEH) and Butterfly Conservation (BC), and is jointly sponsored by a multi-agency consortium of the Joint Nature Conservation Committee (JNCC), Natural Environment Research Council (through CEH), BC, Department of the Environment Food and Rural Affairs, Natural Resources Wales, Natural England, Northern Ireland Environment Agency, Forestry Commission and Scottish Natural Heritage.
UKBMS data is widely used for research; a list of publications as well as downloadable PDF copies of past Annual Reports is made available via the UKBMS website.
Datasets currently available for download are yearly calculations of species trends and collated indices of abundance, as well as yearly updated site data. Access to other data should be requested directly from the UKBMS.