It is a little known fact that this weekend (28th-29th
August) is European Bat Weekend, an annual celebration of bats organised by The
Bat Conservation Trust.
With seven of the UK’s 17 breeding bat species having been
recorded at Attenborough Nature Reserve, the news of the forthcoming bat
celebration spurred me on to dust off my bat detector and go out looking for
some of Attenborough’s rarely seen nocturnal mammals.
Following a few nights of heavy rain, the forecast clear sky
last Monday night was sure to attract large numbers of hungry bats that would
have been unable to feed during the bad weather. Despite a strong wind (and a
heavy down pour half an hour before leaving the house) I was not to be
disappointed.
Just after dusk and only 10 minutes after arriving on the
Reserve my bat detector started to make some strange sounds likened to wet
slaps, that without the detector were inaudible to the human ear. These were
the sonar calls made by my first bat of the night, a Common Pipistrelle. This
is Britain’s
commonest bat which weighing only 5g (less than a 2p coin) is also one of the
smallest. In spite of its small size the Pipistrelle’s voracious appetite means
it can consume around 3000 insects in a single night!
A few minutes later and having tuned the detector to a
different frequency, a Noctule Bat, one of the largest species in Britain could
be heard as it cruised along its feeding path over The Bund. The characteristic
‘chip chop’ call of the Noctule was replaced regularly with a series of ever increasing
clicking sounds as the bat homed in on its insect prey.
With the going good, I moved to the Works Pond bridge. Here,
the sounds coming from the bat detector became hard to distinguish as large
numbers of Pipistrelles and Noctules were busy feeding over the pond and along
the marginal vegetation. All of a sudden the higher frequency call of a Soprano
Pipistrelle came in to range as it joined in the feeding foray. So similar is the
Soprano to the Common Pipistrelle, that this bat was only identified as a
separate species in 1990.
As I walked through the Reserve towards the Nature Centre, bats
could be heard from all directions. Even in Attenborough Village Common
Pipistrelles could be seen patrolling the street lamp lit roads. Over Coneries
Pond surrounding the Nature Centre I encountered my final species of the night,
the rare Nathusius’ Pipistrelle, first recorded in Nottinghamshire at
Attenborough Nature Reserve in 2006. What a way to end a very exciting night
bat detecting.
How can you get
involved?
September is one of the best times in the year to go out
looking for bats. Numbers will have increased from mid July through to August
as juvenile bats born in June start to fly. Furthermore it is the start of the
mating season for next year’s brood so many males will be seen busy flying
around and using their special mating calls to attract a female. September is also the time when bats begin to concentrate
on building up their fat reserves to see them through the winter.
If you’re looking for a place to start, a basic bat detector
will help you get the most out of bat watching and will aid correct
identification. You can purchase a heterodyne detector from the Nature Centre
for as little as £69. These detectors change the ultrasonic sounds emitted by
bats into sounds that we can hear and can be tuned to the frequency of
ultrasound used by different species.
