Banking on butterflies – a conservation experiment
Nik Shelton of the Wildlife Trust in Cambridgeshire looks at a conservation experiment that could help butterflies tackle climate change.
If you go down to Trumpington Meadows, four mysterious giant letter Es have appeared in recent days. What do they mean and how could they help butterflies tackle climate change?
They are butterfly banks which have been created by the Wildlife Trust and scientists at Cambridge University to explore how structures created from soil which support wildflowers could provide a lifeline for insects.
The Banking on Butterflies project is a partnership between the Wildlife Trust and the University of Cambridge ’s Department of Zoology. It started in 2021 with banks built on chalkland nature reserves in Bedfordshire, and earlier this month it was expanded to include the new area at Trumpington Meadows just outside Cambridge. They are located on the side of the M11 away from the busiest area of the reserve.
“The idea of these features is that they’re a conservation experiment,” explains Dr Andrew Bladon, a conservation ecologist who has been involved in the project from the start. “They’re designed to try and find out whether we can improve habitat for butterflies and other species of insects by increasing the variation in topography.
“We know that climate change is a big problem for insects. The world is warming up and that creates problems for species as they try to maintain suitable temperatures. But features like this are designed to try and make what we call microclimates – areas where shade and shelter generates temperatures that are different from the surrounding air temperature.”
“The banks are designed in a capital E shape to give as many different combinations of features as possible and each one faces a different direction – north, south, east and west.”
Although they are called butterfly banks the team are looking at a range of invertebrates and exploring whether species like beetles and spiders prefer different types of features around the banks.
“We will use this information to help land managers provide features for wildlife,” Andrew continues. “In the long term what we want is to get these rolled out as schemes that nature reserve managers, private landowners or developers who are building wildlife habitat as mitigation for housing development or roads can take up as a standard option that they put in.
“This is part of a wider experiment and it’s the fifth site where we’ve built sets of these banks. The early indication is that they're really good – they’re benefiting biodiversity on the sites.
“With the information we gather here then when we go out and design our next set of banks, we can change the design slightly and put more in of the things that species really liked and in doing so we will evolve conservation.”
While the season is winding down for butterflies there are still plenty to see on the wing including red admirals, cabbage whites, peacocks, meadow browns and painted ladies. This year seems to have been a good one for butterflies, however last year the charity Butterfly Conservation’s annual Big Butterfly Count recorded the lowest numbers ever seen. Overall more than half of UK butterfly species are in decline – so projects like Banking on Butterflies are vital if we are to halt the loss and help them fight back.
As summer fades and the colours of autumn arrive there’s lots to do on our reserves and at our events to discover and enjoy wildlife. One of the highlights of our autumn events calendar is our Apple and Harvest Fair at Ramsey Rural Museum on Sunday, 12 October between 11am and 4pm.
There will be lots to do for all the family celebrating harvest time and nature with food and drink, live music, molly dancers, arts and crafts workshops, sustainable gifts, games and a chance to learn about the heritage and history of the Fens. You can also enter the wonkiest vegetable and scarecrow competitions!
Find out more on this and all our events at wildlifebcn.org/events.