How Wildlife Trust and University of Cambridge are exploring climate change impact on butterflies

Climate change is having widespread impacts on the natural world, with many species now emerging earlier in spring and moving further north to track changing temperatures.

However, the distribution of species can also change more subtly at a local scale - within a nature reserve, smaller creatures, such as insects, can move from south to north-facing slopes or from open to shrubby habitat as temperatures warm, seeking cooler conditions in their local patch.

Understanding this fine-scale habitat choice and its effect on the temperature of organisms can be key to designing conservation management to protect biodiversity against the impacts of climate change, helping temperature-sensitive species to survive.

During the last 15 years, the Wildlife Trust, in partnership with researchers at the University of Cambridge, have been studying the impacts of temperature on butterflies in chalk grassland reserves in Bedfordshire in a collaborative approach, which means being able to underpin habitat management with sound scientific data.

Researchers, teams of Wildlife Trust ecology group volunteers plus undergraduate and postgraduate students from the university have carefully mapped the distribution of butterflies, quantifying preferences for different vegetation types and slopes.

Butterflies have had their temperatures taken (using very fine thermometer probes touched on their abdomen), to measure how well different species control their body temperature in different weather conditions.

This has shown that different butterflies have very varying habitat preferences across reserves, and varying abilities to control their temperatures. For example, the brimstone butterfly can keep its body temperature fairly stable across a range of conditions, by contrast the rare Duke of Burgundy has body temperatures which increase rapidly in warming weather.

Intriguingly, different species control their temperatures in different ways, some seeking out warmer areas in cooler conditions, while others are able to control their body temperature independently (through activities such as sun-bathing).

The species that rely on choosing areas with the right temperature conditions are also the species that have declined most across the UK, suggesting that climate change is particularly detrimental for these more temperature-sensitive species.

More recently, the team has started to investigate the effects of temperature on caterpillars. As caterpillars are much less mobile than adult butterflies, it is likely that they are even more sensitive to temperature change, and with information from this wealth of research, the Wildlife Trust has been able to tailor management for species on their reserves, ensuring that conditions are right for threatened species into the future.

An exciting new experimental project builds on this work, and in early September work will begin to create new areas for butterflies at the Wildlife Trust’s Totternhoe and Pegsdon Hills nature reserves in Bedfordshire, funded by players of People’s Postcode Lottery, Nature-based Solutions Fund along with a Cambridge Conservation Initiative knowledge-exchange PhD grant.

Located in flat, ex-arable areas, the project will see the construction four 15-metre long and two-metre high banks on each reserve, each facing different directions of the compass, to produce more varied temperature conditions for butterflies and other species.

The project team has already marked out bank areas on the ground, installed a network of data loggers (tiny remote devices that record temperature every hour), and begun to monitor butterflies and caterpillars. Once the banks have been constructed, monitoring will continue over the coming years, allowing experimental assessment of whether the banks provide the right conditions for temperature-sensitive species.

The effects of climate change on the natural world are not going away, but we can help reduce the impacts of local warming on species, and create a more robust future for wildlife.

Wildlife at Work

Many companies have green spaces and gardens where there's plenty of opportunity to encourage wildlife to flourish.

The Wildlife Trust’s 2021 Wildlife Gardening at Work competition brought some adaptations from last year's awards to allow entries not only from workplace grounds, but also from home-workers’ gardens.

There were some inspiring entries which demonstrate how these awards help to encourage companies and their employees make a real difference for wildlife at their place of work, thereby benefitting and boosting employee wellbeing.

Participants were asked to complete as many tasks as possible from a list of 30 wildlife gardening challenges chiming with the goal of the Wildlife Trusts movement nationally, to secure at least 30 per cent of land and sea for nature’s recovery by 2030. These included everything from taking a wildlife photo and feeding birds, to creating a new wildflower meadow and starting a wildlife pond.

Arthur Rank Hospice took first place by successfully completing 21 of the 30 wildlife challenges, including a badger sighting and a creative collaboration, with the hospice knitting group to brighten paths with wildflowers and lamppost decorations.

Second place went to Unilever Colworth Research, who created wonderful wildlife areas with wild vegetation, dappled shade and plenty of water throughout, highlights including a bee orchid saved from the mowers, and a frog enjoying a watery haven.

Thanks to Granta Park for sponsorship.

For more on corporate support please visit www.wildlifebcn.org/support-us/corporate-support.

For trust membership please visit www.wildlifebcn.org/become-member.

Read more

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Cambridge Conservation Forum: Bringing together a diverse group of conservationists

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