Sunday, 7 September 2008

Bat Walk, Saturday 6th September 2008

When I looked out of the window at 6:00 pm it was raining again! No-one's going to turn up to traipse around the Meadows, at dusk, in the pouring rain, I thought.

Imagine my surprise, then, to get down to the car park and to find 16 people there! And, as it happens, the rain did hold off for most of the evening.

Jim Taylor of the Greater Manchester Bat Group told us about the species of bat that we were likely to encounter on the site ie. Noctule, Daubenton's and Pipistrelle. He explained a bit about their biology and habits and supplied some of us with hand-held, electronic bat detectors. Bats locate their prey by echo location but the sounds that they emit are very high frequency and hence inaudible to most people (I could sometimes detect these calls when I was younger - but it was like someone inserting a fine needle into my ear drum! I'm rather glad that I can't hear them any more!). The bat detectors reduce the frequencies of these calls and make them audible.

We all walked through the woodland to the river bank and suddenly the detectors chattered into life. The first species we heard was a Noctule (Nyctalus noctula) whose call the detector renders as a rapid "chip-shop, chip-shop!" sound. This was followed by a Daubenton's (Myotis daubentoni) which sounds a bit like a revving motorbike.

As we walked along the river bank, in the direction of Jackson's Boat, we began to detect the rapid, slapping sounds of Pipistrelles (Pipistrellus pipistrellus). At one point we descended some steps to a sheltered spot below the river bank and suddenly the air was full of Pipistrelles and the detectors were slapping away like mad. Jim's powerful lantern beam picked up the tiny bats flitting through the air and also the thousands of flying insects that they feed on.

So, a very successful evening, in spite of the weather. I hope that everyone who attended enjoyed it. I will ask Jim to write a more detailed account in due course.

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