Last year, whilst exploring a potential One Nighter site on the coast, we were lucky enough to stumble upon a Greater Horseshoe bat (Rhinolophus ferrumequinum), sleeping in a little alcove. This was a first for me… and it made my night. No. My week – It was amazing! At the time we had no idea it was a Greater Horseshoe bat. I mean, we knew it was a bat, but beyond that, not the foggiest idea what it species it was, if it was a common sight in such environments, or what we could/should do under the circumstances. We decided to take some photos so we could positively identify it (maybe with a little help) and tell someone about it.
On seeing the photos my good friend (and highly recommended ecologist! 😉 ) Georgie Starkie, set us on the right track by identifying the little chap as Greater Horseshoe and explaining a bit about the fascinating world of bats. Some of my favourite facts include:
- There are 17 known breeding bat species in the UK (but 1,300 throughout the world!)
- The largest bats are the flying foxes with wingspans of up to 2 metres, whilst the bumblebee bat, weighing only 2 grams is the world’s smallest mammal!
- Bats in the UKeat only insects (but worldwide, bats’ diets are known to include frogs, fruit, other bats, nectar from flowers, blood, pollen and fish!)
- Some bat species roost in caves, hanging upside down, but actually, many species prefer to hide in nooks and crannies, under rocks, in people’s roofs, or even up in the trees in the woods.
It doesn’t stop there though. It turns out that not only are bats super cool, they’re also declining in numbers in the UK, and as a result protected from harm by UK end EU law. People committing bat crimes can face six months imprisonment and/or unlimited fines! Shockingly the Bat Conservation Trust (BCT) reports that
“The greater horseshoe bat has shown a marked decline. It is rare in Britain and now confined to southwest England and south Wales. It is estimated that the number of greater horseshoe bats has declined by over 90% in the last 100 years”
The bat we found back in December was likely hibernating. Like a lot of mammals, bats actually spend a large portion of the year (roughly October-April) in a state of hibernation or torpor, induced by low temperatures and short days. During this time they experience a controlled reduction of body temperature and a fall in oxygen consumption and metabolic rates. This, as I’m sure you can imagine, is a bad time to be woken by a noisy new roommate, but more than that, disturbance of winter roosts is recognised by the BCT as a likely contributor to their decline in numbers.
Yesterday I joined Chris, one of our project followers, for a sunny stroll on Dartmoor to check out a few of the caves we were hoping to use to launch the Wild One Nighters project later this week. Chris, a self-confessed Dartmoor enthusiast, has been involved with both the Plymouth Caving Club and the local Bat Group, and agreed to share some of his knowledge and experience to help ensure our activities didn’t disturb these fantastic animals. After a great mornings’ careful investigation of some cracking sites, we concluded that there was enough evidence in the places we visited to suggest they are home to hibernating bats, and hopefully will be until April. With these discoveries in mind, we have decided to make a few last minute changes to our running order and restrict our Wild Subterranean Nights to the summer months. (Don’t worry about the cryptic clue, we’ll bring that one back out in May when we take the project underground!)
In the meantime, remember, if you find yourself venturing into a cosy looking cave this winter you might not be the only one with the same idea so keep the noise to a minimum and the lights down low 🙂
For those interested in finding out more about bats, including all our UK species, upcoming special events and what to do if you encounter one on your travels, check out the Bat Conservation Trust, or local bat group the Devon Greater Horseshoe bat Project