[THIS DATASET HAS BEEN WITHDRAWN]. Butterfly data from the UK Environmental Change Network (ECN) terrestrial sites. Counts of individual species are recorded. These data are collected while walking a defined transect at all of ECN's terrestrial sites using a standard protocol. They represent continuous weekly records from 1993 to 2012. ECN is the UK's long-term environmental monitoring programme. It is a multi-agency programme sponsored by a consortium of fourteen government departments and agencies. These organisations contribute to the programme through funding either site monitoring and/or network co-ordination activities. These organisations are: Agri-Food and Biosciences Institute, Biotechnology and Biological Sciences Research Council, Cyfoeth Naturiol Cymru - Natural Resources Wales, Defence Science & Technology Laboratory, Department for Environment, Food and Rural Affairs, Environment Agency, Forestry Commission, Llywodraeth Cymru - Welsh Government, Natural England, Natural Environment Research Council, Northern Ireland Environment Agency, Scottish Environment Protection Agency, Scottish Government and Scottish Natural Heritage. Full details about this dataset can be found at https://doi.org/10.5285/dad68dc4-9e36-457e-aa3a-e7eb816fb508