The Department of the Environment has co-ordinated the Jersey Butterfly Monitoring Scheme (JBMS) for the last ten years, depending on a team of unpaid volunteers who count butterflies each week throughout the spring and summer at 38 locations across Jersey. The 10 year butterfly report has now been published online and is available to download here

The scheme is one of the ways Jersey meets its international environmental obligations, butterflies are environmental bellwethers and in line with countries around the world, the Department of the Environment monitors Jersey’s butterfly population to detect changes to the environment.

What happens to Jersey’s butterfly data?

The JBMS raw data are collected and collated by the Department, copies being passed on to the Jersey Biodiversity Centre, Société Jersiaise, the UK Butterfly Monitoring Scheme, Butterfly Conservation and the EU Environment Agency. The Island has 40 monitored sites (which is more than several European countries) and punches well above its weight. JBMS data are used in local, national and international analyses such as the European Grassland Indicator Butterfly Scheme. The results are analysed annually and after 10 years of continuous monitoring the data obtained enough statistical significance to undergo a more thorough analysis, the results of which are presented in the new report.

What does the JBMS tell us about the island’s environment?

The JBMS 10 year results suggest that Jersey’s butterflies respond quickly to changes in the environment so are thus an excellent indicator of changes in the island’s terrestrial habitats and climate. The results suggest that there has been an overall decline in Jersey’s butterflies since 2004, especially on agricultural and urban sites, but that managed semi-natural sites are mostly doing well. Now that these and other issues have been highlighted by the JBMS, it may be possible to help mitigate and reverse any declines in species and habitat quality through government policy and changes in land management practice.

In dedication

The butterfly report is dedicated to two of Jersey’s foremost naturalists. Margaret Long and Joan Banks were instrumental in setting up the Jersey Butterfly Monitoring Scheme. They had tested a similar scheme in the 1990s and in 2004 used the data from this to establish butterfly transects around the island. They also provided background knowledge on Jersey’s butterflies and continued to support the scheme for many years. Without them the Jersey Butterfly Monitoring Scheme would have been much harder to get off the ground. We remain very grateful for all their help and support. Margaret kindly helped Birds On The Edge with the development of this website.

Download the full report here