Sopwell Nunnery Bat Walk report

Chris Pudsey reporting (photos by Peter Wares)
 
Bat walk 29 August 2014

 
A good-sized group of about 30 local residents met in the Nunnery Green Space on a rather dull and breezy evening. Not very promising - but the threatened rain held off, the wind dropped just in time, and the amount of fidgeting and scratching indicated that there were plenty of midges about to attract the bats.

While it slowly got dark, our bat expert and licensed bat handler, Roger Harvard, told us lots of interesting facts about bats, showed us some cardboard silhouettes to compare their sizes, and finally introduced us to a cat-damaged pipistrelle which can no longer fend for itself and so has been living with him for several years.

Contrary to what some people still think, bats are not at all scary, but are small, furry and (OK, I admit it!) extremely cute.

By this time it was nearly dark, so we were issued with bat detectors to share. Bat detectors are electronic devices that, like radios, can pick up the bats' high-pitched echo-location signals and wind them down to a pitch that even those of us with older ears can hear. Our detectors were tuned for picking up pipistrelles, which Roger thought we were most likely to encounter.

Thus equipped, we ambled across the open space and along the river from Cottonmill Lane to Holywell Hill. Our best 'sightings' were in the stretch near the bottom of De Tany Court, where the trees are more widely spaced and the river running nearby.
 

Bat walk 29 August 2014


Quite a few people dropped out at Holywell Hill and on the way back as we got near to where they lived, but those who stayed to the end were rewarded by a longer display near the Ver Valley Walk bench back on the open space. With the help of Roger's powerful torch shining on the trees, we watched a bat weaving backwards and forwards along the river, hearing the crunching sounds on the detectors as it collected its supper.

Thanks to Roger for a fascinating evening - and to Sandy Norman and the SRA for organising it!

Some interesting facts about bats:

  • There are 17 species in Britain. The smallest, and the most common around here is the Pipistrelle, the largest being the Noctule.
  • Bats make up a quarter of all mammal species both worldwide and in the UK. They are useful creatures. Many are pollinators - e.g. in Mexico, bats pollinate agave flowers, so without them there would no tequila! Some species - important in regenerating rain forest - eat fruit from forest trees, fly over bare patches and seeds in their droppings start new trees growing.
  • All British bats are insect-eaters. Pipistrelle eats up to 3,000 midges, gnats, small flies and micro-moths per night. Long-eared bats lurk above tree canopy listening for spiders. Daubenton's bats swoop low over water, grabbing insects with their feet. 
  • They are social animals, roosting in large groups. Babies are born without fur, and huddle together on the south-facing wall of roost to keep warm while their parents go hunting. Vampire bats in S. America even run social welfare programme - bats that can't forage or fail to feed, will be fed by others.
  • Bats have only one offspring a year, so need to be long-lived to keep numbers up. Record for a British bat is nearly 40 years! 
  • Their only predators are hobby (small falcon) and - most important - domestic cats. Cats can hear echo-location signals, so can find their roosts and feeding grounds. Most bats rescued by bat group have been injured by cats. 
  • All species of bat and their breeding sites or resting places (called roosts) are protected. It is an offence for anyone to kill, injure or handle a bat, to possess a bat (whether live or dead), disturb a roosting bat, or sell or offer a bat for sale, without a licence. It is also an offence to damage, destroy or obstruct access to any place used by bats for shelter, whether they are present or not.
  • Bat numbers have declined dramatically in this country - predation, loss of habitat and roosts (house-building methods), fewer insects etc. But I suppose at least we now go on walks to look for them rather than running away screaming if one gets too close!

 
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Chris Pudsey