More night flyers by Peter Shallcross

Photo - LiCheng Shih - www.flickr.com

We often see bats at dusk, flying above our gardens and streets, but most of their lives are hidden away. (This photo of an unidentified bat was taken in Taiwan, but I think it's rather sweet, as bats go - Ed.)
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Recently ‘bat detectors’ have revolutionised what we know about the distribution of different species, where they feed and what they get up to.  Bat detectors pick up the echo-location signals from bats and from the particular frequency can tell most of the species apart.  Gareth Harris (who is Wiltshire’s Mammal Recorder) positioned a detector on a tree near the river at Wallmead Farm for a month.  The results were astounding!

There was so much data that Gareth could only analyse a small sample but 10 species were identified with another three broken down to genus only.  The list below refers to the number of passes recorded by each species so indicated activity and not necessarily abundance.

It shows that there are many species of bats locally some of which are rare (highlighted in red)
and there must therefore also be plenty of a whole range of insects for them to eat, especially down by the river, as different species of bats most likely specialise on different insects. 

Greater horseshoe 2
Lesser horseshoe - 4
Whiskered/Brandt's bat - 1
Daubenton's bat - 119
Natterer's bat - 7
Myotis sp. -2145
Noctule bat - 15
Leisler's bat - 9
Nyctalus sp. - 2
Serotine bat - 7
Common pipistrelle - 1572
Soprano pipistrelle - 1324
Plecotus sp. - 190
Grand Total - 5297 (NB these are passes, not individual bats)

Gareth now plans to coordinate a farmer cluster group meeting on bats here soon and draw on these results.
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