Wednesday, 19 June 2013

Bat-Air Traffic Control

Last Friday an odd thing happened; the wind dropped, the clouds parted and the evening air was warm... The bat walk I had organised actually went ahead and 8 of us were led through Upper Picketts Wood by Martyn Cooke of Surrey Bat Group (also an air traffic controller here at Gatwick).

Torchlight trek through Upper Pickett's Wood

Gatwick's Land East of the Railway Line

As the sun was setting we stopped off at Roll's Farm, an old abandoned farm house by the sewage works. With its wild, tangled garden and loose roof tiles it really looks like the perfect bat haunt. Our bat detectors were on and we were busy chatting when suddenly a series of louds clicks swept us by... A Common Pipistrelle (Pipistrellus pipistrellus) was on the wing and loudly echolocating! Martyn was able to show us on his Anabat detector screen the 'hockey-stick' pattern of a Pipistrelle call:

The call of a Common Pipistrelle bat (Pipistrellus pipistrellus) which peaks between 45 and 50kHz

People were excitedly pointing but annoyingly I still couldn't see anything. It was getting frustratingly dark - suddenly I saw my first Pipistrelle bat as it veered around us, much lower and closer than I had expected! No chance of them bumping into us though as these tiny predators are aerial experts, catching their insect prey and eating on the wing. Martyn said they were probably feeding on midges which our group was attracting in (and beginning to feel!) I did my best to get a photo, if you look carefully you can just about make out the tiny bat as it shot past...


Ok a little joke, I didn't attempt a photo. However it was a great privilege to see and hear these usually unnoticed creatures. We heard only Common Pips but then at the very end of the walk we heard a Soprano Pipistrelle (Pipistrellus pygmaeus), which were only recently declared a separate species. Martyn is a brilliant source of bat info and has some great stories, including the only reported 'bat strike' in the UK... (Disclaimer Alert: bats pose zero threat to aircraft!)

Light Emerald moth (Campaea margaritata)

We also tested out torching for Great Crested Newts at our two woodland ponds; we were able to make out 2 large female G.C.N. and 1 small male. Also spotted were several Smooth Newts and 2 Common Frogs. While people were using their torches I was attempting (and mostly failing at) bare-handed capturing of moths drawn in by the light. I did manage to grab 2 macromoths which I potted and took home to photograph in the daylight.

Light Emerald (Campaea margaritata)

Common White Wave (Cabera pusaria)

Common White Wave (Cabera pusaria)

I feel a bit mean that I haven't shown any pictures of a bat, so here is a photo of two lovely little Common Pipistrelle, one of which a friend of mine rescued in Copthorne back in 2007. We took it over to the Jenny Clark of Sussex Bat Group who rehabilitated and released it back into the wild...

'Boost' the female pipistrelle and her new buddy 

You can find out about all of the UK's different bats species here: Bat Conservation Trust