Each armed with a small bat detector unit, members of the Friends set off for a twilight walk around the grounds of Juniper Hall on a mild September evening. There were magical moments when the detectors enhanced the rapid clicking sounds of approaching bats and silhouettes of these tiny mammals were glimpsed as they flew over our heads searching for their dinner of moths. As the light faded to darkness we retreated to the Templeton Room for tea and biscuits and a fascinating talk given by knowledgeable members of the Surrey Bat Group.
We learnt that the UK has 17 breeding species of bats (out of 1,500 species worldwide – making up a quarter of all mammal species in the world!) All UK species are protected by law, due to declining populations resulting from a range of pressures like agricultural intensification and loss of hedgerows; commercial forestry reducing biodiversity and roost holes; pesticide use reducing insect prey populations; predation by domestic cats; modern breathable roof membranes entangling bats; and lethal timber treatments that persist for years. Bats often congregate in maternity roosts, generally breed just once a year and produce a single baby each. They are also highly vulnerable during their winter hibernation when they need to find a cool, humid and safe place to sleep out the season when insects are too scarce to support them.
Conserving the world’s bats is important, not only for their own sake, but also for the role they play in the ecosystem, keeping pest insects in check, pollinating plants and spreading seeds and regenerating forests.
Our bats have a variety of roost preferences; some seek out the holes that form in large old trees while many species use parts of buildings like lofts, holes in walls and gaps under tile hanging. We can all help our bats to thrive: by providing extra roosting opportunities including bat boxes, by managing our gardens in a wildlife friendly way, including planting native plants that attract pollinating insects, adding a pond or water feature, leaving areas of the garden naturally untidy, by avoiding pesticides, keeping the garden dark at night (no outside lights and closing the curtains), and keeping cats indoors at night (or at least at dusk when bats are most active).