Calling all bats to our buffet!

On these warmer and brighter evenings, it’s quite possible you could catch a glimpse of one of our most fascinating groups of mammals; the graceful, airborne bats.

Bats are the only true-flying mammals, and with our 17 species they actually make up more than a quarter of all mammal species in the UK. At dusk, on a warm summer evening, you’re likely to see these winged beasts swoop close by as they hunt for insects, which they certainly have an appetite for! A common pipistrelle bat weighs only the same as a one-pound coin, but it can consume up to 3000 insects in one night.

Our bats at Coombes Valley certainly have a hefty appetite, especially for moths! Whenever there’s a still, dry night we set up our moth trap, which draws hundreds of the fluttering creatures to its bright light. On our bat walk on Friday night, we used bat detectors to pick up the echolocation calls that bats make. From the frequency of calls recorded it would seem that the pipistrelle bats of Coombes have discovered our moth trap; an all-you-can-eat buffet!

I must admit, a pink and green elephant hawkmoth does look as though it would make an exotic meal!

An elephant hawkmoth caught in our moth trap on Friday 1st August, photo by Lucy

Bats are amazing navigators, as all UK species use echolocation to find their way around and hunt for food. They will actually use linear features in the landscape as ‘bat highways’, rather like the roads we use to get around. As they fly, their echolocation calls are bounced off features like hedgerows, woodland edges and rivers; it’s quite easy to watch them zip along hedges at dusk.

A bat detector is a great tool to have, to get an idea of what type of bat you might have seen flying about. You can set the detector to pick up different frequencies, most of which are too high-pitched for our ears to detect. Different bat species echolocate within different frequency ranges according to their habitat and prey types. This means you can get an idea of what type of bat is zipping above you just by listening to them.  

A common pipistrelle bat in flight, photo by Laurie Campbell, RSPB Images.

Our native bat species occupy a wide variety of habitats, ranging from woodlands and farmland, all the way to urban areas. As well as affecting food supply, changes in land use have meant fewer suitable roosting and hunting places.

True to their stereotypes, bats do actually use caves to roost in. However, this is only one of several types of place they like to roost; others range from old, gnarly trees to the eaves of churches and houses. As forest habitat has diminished, so too have the number of trees suitable for roosting, meaning bats now need help from us.

One way in which we can do this is by making bat boxes, which recreate the conditions that bats like in their roosting spots. Why not have a go at making one yourself? You find out how, and see how others have got on here: http://homes.rspb.org.uk/Page/project/bat-box

At Coombes we have several of these bat boxes placed throughout the woodland, and at the last count we  recorded 8 species of bats on the reserve! In addition, Coombes is actively managed to preserve especially old and gnarly trees that provide fantastic roosting sites for bats.

Plan your visit to Coombes Valley for a peaceful walk in the woods, or bring the whole family to explore and see how our reserve is giving nature a home.

Phone the office on 01538 384017 or visit us online at www.rspb.org.uk/coombesvalley for more information.