29th May 2019

Impact of hedgerow management on bats

(c) Daniel Hargreaves

by Jérémy Froidevaux

Hedgerows are an extremely important habitat feature for bats in the UK as they provide food, shelter and valuable landmarks for their orientation. However, little is known about whether changes in the management of hedgerows could make them even more beneficial to bats and their insect prey. For instance, specific agri-environment schemes, designed to promote biodiversity in farmland, have encouraged farmers to trim hedgerows no more than once every three years to enhance populations of the greater horseshoe bat – a species of major conservation concern.

In this study, researchers investigated whether delayed hedgerow trimming affected the activity and diversity of bats and insect prey within farms in Southwest England. Their results showed that the greater horseshoe bat as well as other non targeted species including the lesser horseshoe and long eared bats all benefit from a delayed trimming regime. The abundance of insect prey were also enhanced suggesting that untrimmed hedgerows may harbour more prey. Untrimmed hedgerows also had a more prominent and complex structure than those trimmed yearly, meaning they could be better landmarks for commuting and foraging bats. While the less severe trimming regime prescribed by previous and current AESs in England encourages farmers to trim hedgerows only one year in three, our study largely supports the longer term benefits of non‐trimming on bats and their insect prey. Keeping some hedgerows untrimmed for up to 10 years would enhance bat species richness and insect family diversity. Overall, this study shines a light on the success of targeted agri-environment schemes for promoting some of the most threatened bat species in Western Europe".

The research was published in the Journal of Applied Ecology: Managing hedgerows for nocturnal wildlife: do bats and their insect prey benefit from targeted agrienvironment schemes? https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2664.13412