Research into bat populations held at Hestercombe

Hestercombe is working with researchers to find out how light pollution affects bat populations.

The University of Bristol is currently undertaking research to determine how light pollution affects the behaviour and wellbeing of bats. With the help of Hestercombe staff, and under licence from Natural England, they are examining how LED security lights alter the emergence behaviour and roosting behaviour of lesser horseshoe bats at roosts.

The buildings and grounds of Hestercombe are home to a variety of bat species, including the lesser horseshoe bat (pictured). Bats are most active at night when they hunt for their insect prey, which they do using a highly sophisticated form of echolocation. In England, our smallest bat, the soprano pipistrelle, is estimated to consume up to 3,000 small flies, such as midges, in a single night and so bats are thought to provide important ecosystem services as well as additional benefits to humans associated with the control of insect populations.

 Light pollution is a rising global problem, affecting every inhabited continent. As human populations rise and become increasingly urbanised, levels of light pollution are set to increase. Being largely nocturnal, bats have an innate aversion to light, and typically avoid flying in lit conditions to minimise the risk of predation from diurnal birds of prey. Despite this, some fast-flying bat species such as pipistrelle bats, which are better able to evade predatory birds, have learned to exploit insect communities that are attracted to and congregate at streetlights. Slow-flying species, however, such as the lesser horseshoe bat, appear to remain intolerant of lit conditions.

 Almost one quarter of bat species globally is threatened and the key underlying threat to populations is pressure on resources from increasing human populations. Light pollution in particular ranks as a key emerging issue in biodiversity conservation, affecting critical animal behaviours including foraging, reproduction and communication.

Visitors are welcome to come and see the bats roosting in the visitor centre at Hestercombe via a live video link.

Find out more about the study at and about Hestercombe at