As darkness fell, Cam gave the group a brief introduction to bats and their behaviour. We were that after a wet few days it was a still and dry evening, which is ideal, as bats cannot “see” well (i.e. echo-locate) in the rain and so don’t come out to hunt. All 18 species of British bat are insect-eating - or insectivorous - nocturnal, flying mammals. Understandably, they prefer hunting for insects on still rather than windy nights.
They hunt using “echolocation”, locating things by their echoes. To do this, bats make sounds and the returning echoes give the bats information about anything that is ahead of them, including the size and shape of an insect and which way it is going.
We shared out our bat detectors, which are small boxes which translate the bats’ high-pitched squeaks into sounds we can hear. As it became dark we set off up Cross Gates Lane behind the golf club, towards the tree-lined fields and derelict barn. At the edge of the golf course, sheltered by the trees, we spotted our first Pippistrelle bats.
Watching bats, St Ives, Bingley - Saturday 9th September 2017
Further on the barn the detectors soon picked up bat activity. Shining torches up at the trees, we soon spotted more Pippistrelle bats. They were flying just under the canopy of the trees – where the branches spread over the lane to form a long high “tunnel” and the insects shelter from the breeze.
After watching and listening at the barns we moved back down the lane and on to Coppice pond, where the water attracts lots of insects and we were able to hear Daubenton’s bats - the “water bat” - moving out over the lake. The bat species can be told apart by their behaviour and the frequency of their calls: how high or low they squeak. Though we did not find it easy to differentiate many species, there was lots of bat activity to keep us occupied.
There was also an eerie mist forming over the water, moving gently over the surface, giving the whole scene a spooky vibe!
Watching the Daubenton's Bats, St Ives, Bingley - Saturday 9th September 2017
We also saw some white-clawed crayfish in the pond shallows. These are small, fresh-water lobster-like crustaceans. St Ives Estate have undertaken work to encourage the endangered white-clawed crayfish in Coppice Pond. Just like our bat walk two years ago, we found a Moorhen, roosting in a flimsy branch overhanging the pond. This may seem an odd place for us to sleep, but for a Moorhen it's the perfect place to sleep safe from Mink and other predators.
White-clawed Crayfish, St Ives, Bingley - Saturday 9th September 2017
Once again, thank you to everyone who came and made this such an enjoyable event.