Overseen by the UK Butterfly Monitoring Scheme https://ukbms.org/about
This involves volunteers walking weekly along a chosen route and counting all butterflies during a 26-week period between 1st April and 29th September each year
Butterflies act as important indicators of the health of the environment.
Monitoring their numbers enables us to assess the impacts of climate change and the effects of national and local policy initiatives.
Their rapid lifecycles and high sensitivity to environmental conditions make them a highly effective indicator species.
Establishing a Transect and How to Record
- Transects should take about 45-60 minutes to walk and be about 1mile in length.
- Identify a route (transect walk) that provides a fair representation of the habitats and other features
present at your site.
- This transect is ‘fixed’, in other words the same route should be followed each year
- Recording takes place once a week from April 1st to the end of September.
- Transect counts should ideally be made between 10:45 and 15:45 hours.
- Transect walks should only be carried out in warm (13 C or more) and at least bright weather. The
minimum criteria are 13-17C with at least 60% sunshine, or over 17C and not raining.
The map shows the transect that we started last year in Hartland
Numbers fluctuated each week as you can see from the graph. I could do a graph for each species but it would get complicated!
Rosie Irwin of Butterfly Conservation says habitat loss, pesticide use and climate change are all impacting the population numbers. This year’s fall in numbers has been exacerbated by the wet spring and late arrival of summer temperatures.
We believe that by recording butterfly numbers over a long period of time we can provide useful information to help guide how best to conserve our environment.