Thursday, July 25, 2013

Pipistrellus pipistrellus

 The Nocturnal Paratroopers

There are bats at Le Ripe and there certainly always have been. When we first arrived to survey the semi-ruins of our future home we discovered bats in the cellar, bats in the bedroom and bats in the barn. Yet they are elusive creatures and for five years now, since the renovations, we have not seen many.

However over the last couple of days I have been lucky enough to sight bats again at Le Ripe. The other evening, at dusk but well before dark, I happened to notice a small, dark round shape zipping out of our bat box (more on this below); I focused my gaze on the bat box and was treated to the sight of a second small round shape zipping out after the first. The image this called to mind when I tried to describe it was of two action film paratrooper commandos bombing out of a helicopter, diving down towards their mission, their parachutes (in this case the bats' wings) still furled behind them.* 

The following morning, a second treat. It was about 7.40, the sky was already light, the sun on the horizon. I was standing on a terrace above the house thinking sleepily about my next task when I noticed a bat flapping around the house guttering. Surprised the bat should be out so 'late' and delighted that I might have a chance to watch it return to its home in the bat box, I fixed my gaze on it as it flapped over the roof. 

Suddenly it dived into the guttering and next thing there was a comical shuffling and scratching as it made its way along the length of the semicircular copper tube (some 10-12 metres), presumably pulling itself on its winged elbows and little hind feet (how else could it have moved?!). The shuffling continued to the end of the guttering and then turned around and moved back. I have heard many a lizard scuttling in the guttering and even perhaps heard the slither of snakes, but I had never imagined bats crawling there!

guttering or bat food trough
The bat emerged again to fly about but now I could see that the guttering was evidently a very attractive and profitable food trough. The little bat, perhaps dazzled by the increasing daylight, continued to aim at the guttering, bumping into the edge repeatedly until finally managing to slip inside again, where it resumed its comical-sounding, shuffling progress.

Pipistrellus pipistrellus, Common Pipistrelle

How did we come to have bats living so close to the house again after such a long absence?

Several years ago we heard that the Coop, the local monopolistic supermarket chain, was participating in an admirable initiative to repopulate the Tuscan towns and countryside with bats whose numbers had depleted drastically over the decades. A side-benefit of encouraging bats to colonize near human habitation, much emphasized by the organizers, was the subsequent decimation of the mosquito population. The statistic cited was impressive: each bat will consume 2000 mosquitoes in one night! A tempting idea. On looking into the matter a little more carefully we discover that this figure is arrived at by recording the bats' weight before and after eating, then dividing it by the weight of a mosquito. Yet bats do not consume only mosquitoes. All the same we are fairly confident that since bats arrived in our bat box this year there have been considerably fewer mosquitoes about.

Apparently the only bats which will colonize the bat boxes are the following:

Kuhl's Pipistrelle, Pipistrellus kuhlii or  pipistrello albolimbato;
Savi's Pipistrelle, Hypsugo savii or pipistrello di Savi; 
Common Pipistrelle, Pipistrellus pipistrellus or pipistrello nano;
Grey Long-Eared Bat, Plecotus austriacus or orecchione grigio.

We can rule out the Grey Long-Eared as it is apparently rather large and our bats are tiny: our bats' bodies alone look about the size of a walnut. The other three are all what is known as vernal bats, which hunt in the evening (the Grey Long-Eared also hunts by day). Having studied the data and characteristics of these three I feel qualified to make a cautious guess that our little bats are of the Pipistrellus pipistrellus variety, mainly because of their tiny size.

There are some amusing anecdotes associated with the advent of the bat box. For our part, we like to say that the bats took a while to arrive in our box because they had to learn English first. The boxes distributed by the Coop are inscribed rather conspicuously with the words BAT BOX.

Apparently when the bat boxes first arrived on the scene, customers of the Coop asked whether the boxes came complete with bats. Others wondered whether the boxes had to be hung up in the bedroom (to catch the mosquitoes lurking there). Misinformation and simple-mindedness aside, the boxes appear to have been a success.

Now we shall help supply researchers with information about our bats, for the good of all. The Specola di Firenze, the zoological section (an extraordinary if at times gruesome collection open to the public) of Florence's Natural History Museum, is the institution promoting this experiment throughout Tuscany.

La Specola, Via Romana 17 Florence
*Subsequently we witnessed at least twenty-two (22!) bats exiting the bat box. Someone quipped that we were witnessing the Bätterdämmerung. More likely the Twilight of the Mosquitoes.

except for the photo of the guttering, none of these photos is mine: thanks go to the internet.


  1. Nice piece on commando bats. We owe thanks to the earnest efforts of the Museo Specola.

  2. Oh, so fortunate to have a properly inhabited bat box! We've had one for years at Three Peaks attach to the 'Thistle Tree' (a great, ancient gum tree); and it's only ever been inhabited by spiders.
    Loved bats 'about the size of a walnut": perfect.


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