Simon Davies gives an update on this year’s butterfly surveys on Over Stowey Customs Common ~
We have now completed our third full season of weekly butterfly surveys on a specified route across the Common. Four or five of us have taken it in turns to walk the route on the sunniest day we can find each week. Along the way we count all the butterflies that are near to the path, and the results are then collated. They are sent into the UK butterfly monitoring group which uses them to add to the national picture, not to mention the keen interest taken by our Chair and former Chair, Robin and John.
In designing the route we tried to take in different habitats on the Common which are relevant to the types of butterfly that we can expect to find. So we have dry heathland, woodland and marshy ground (mire), amongst others in the 3 km route. The route was also designed to ensure that the option of a visit to see the Styles ice cream van is not forgotten.
The year was slow to get going but numbers were beginning to rise quickly by late May.
This was the warmest year we’ve formally counted butterflies on the Common
- In 2024 we had 4 butterfly walk days in the 20’s (centigrade): 3 in 2023. There were 11 this year!
- Based on cloud cover assessments on the two-hour walks, we had an average of 69% sunshine in 2025 with an identical figure in 2024. Perhaps surprisingly this was 80% in 2023
- We counted a total of 809 butterflies (645 in 2024 and 1,285 in 2023)
- In terms of butterfly diversity, 147 of 18 species was our best day this year (91 of 11 species in 2024; 161 of 14 species in 2023)
We hit a new species total of 27 this year
We saw all the species seen previously bar two (Dark green fritillary and Brimstone) and with two new species, Purple Hairstreak and Clouded Yellow added to our list.
Can we extend that further in years to come? It will be difficult, but we will be out looking!
