Heatwave predicts a shady future for insects: impacts of an extreme weather event on a chalk grassland in Bedfordshire, UK.

Abstract

Abstract Climate change is set to become one of the leading causes of biodiversity loss worldwide, with extreme weather events projected to increase in frequency. Ectothermic animals such as insects are at particular risk, especially when they are isolated and unable to move through the landscape to track suitable climate. To protect such taxa, it is important to understand how they are impacted by extreme weather events and whether management could provide effective microclimate refuges. However, potential management interventions remain untested for many species. Here, we show that extreme high temperatures experienced in the UK on 19th July 2022 resulted in a community of butterflies becoming inactive, but that shaded areas, including artificial slopes created as part of conservation management for climate change, provided a refuge during this period. Our results indicate that future high temperatures could force butterflies to shelter in the shade, potentially being unable to fly, feed or mate during these periods, with potential long-term impacts. Implications for Insect Conservation Producing artificial slopes and integrating patches of scrub within grassland could create an array of microclimates that allow butterflies and other invertebrates to thermoregulate, providing a refuge during extreme weather events. Our findings highlight the dramatic effect of extreme temperatures on insect communities, as well as simple management solutions that could be implemented widely and relatively easily by conservation managers, to counter some of the negative impacts of rising temperatures and extreme weather events.