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Welcome to the World of Bats
All UK bats and their
roosts are protected by law. It is illegal to harm or disturb or deliberately
disturb their roosts without first seeking advice from your local Statutory
Nature Conservation Organisation.
Bats are mammals and as
such are warm blooded, have fur or hair on their bodies and feed on their
mother’s milk for the first few weeks of their life. However bats are the
only mammals that are capable of true flight.
Bat’s wings can be likened
to our arms and hands but have extra long fingers with skin stretching between
the body and fingers to form the wing membrane. Only the thumb remains free
which is used for grooming.
Seventeen species of bat
have been identified in the UK, four of which have been seen in the country
park.
The smallest bat found in
the UK, and the country park, is the pipistrelle which is around 4cm long and
weighs around 5g. (less than the weight of a £1 coin).
The largest bat species in
the UK, and the country park, is the noctule with a body length of 6-8.2cm and a
weight of 19-40g.
This is still small
compared to the world’s largest bat, the Kalong or Javanese flying fox, which is
a fruit eating bat found in East Asia, which has a wingspan of almost 2 metres!
All native UK bats eat
insects and the majority catch and eat them in mid air. Amazingly the tiny
pipistrelle can eat over 3000 insects in one night!
Bats are not blind but
during the hours of darkness they fly using echolocation i.e. locating objects
by echo. They emit high pitched sounds, which us humans cannot hear, and
instinctively measure how long it takes for the noise to bounce back from the
objects in their way.
Bats don’t make nests but
choose places to roost such as hollow trees, caves or buildings. UK native bats
hibernate in winter as there are few insects to be found at that time of year.
To use less energy their heartbeat, breathing rate and body temperature drop.
The four bats species
identified in the country park are:
|
Species |
Whiskered |
Noctule |
Pipistrelle |
Brown Long-Eared |
|
Life span (yrs)
(max recorded) |
24 |
12 |
16 |
30 |
|
Body length(cm) |
3.5-4.8 |
6-8.2 |
3.5-4.5 |
4.2-5.3 |
|
Wingspan(cm) |
20-25 |
32-45 |
19-25 |
24-28 |
|
Weight(g) |
5-9 |
19-40 |
3-8 |
5-12 |
|
Description |
Upper-dark brown
Under-greyish
white
Face, ears, wings
-dark grey/black |
Fur-short golden
brown
Ears, nose, wing
membranes - dark brown |
Upper - dark
red/brown
Under
-yellow/brown
Ears, nose, wing
membranes -black/brown |
Fur - buff brown
Face -pink brown
Ear&wing - light
grey brown |
|
Diet |
Dusk – midges,
beetles & moths |
Early, often
before sunset -moths, beetles & large flying insects |
Early, sometimes
before sunset - moths, gnats & small insects |
Moths in flight
caterpillars,
spiders from leaves/twigs |
|
Flight |
Fluttery and slow |
Fast & high above
ground |
Rapid, agile about
5-10m above ground |
Slow fluttering –
often close to ground |
|
Reproduction |
Mate while in
hibernaculum. Young born mid June |
Mate Aug-Oct
1 young July |
Mate Aug-Sept
Usually 1 young
June/July |
Mate autumn
1 young mid June |
How a bat detector works 
Human’s hearing range is
between 20Hz and 15-20kHz. Some bats are able to hear sounds at up to 110 kHz.
To be able to “hear” bats a bat detector can be used. The bat sounds are
detected by an ultrasonic microphone and mixed with a high frequency oscillation
in the bat detector. This produces sounds which are the sum and the difference
of the two frequencies eg. If the bat detector is set to 50kHz and a pipistrelle
is heard whose sound is at a frequency of 45kHz, the sum 95kHz can’t be heard
but the difference 5kHz can be. The frequency of the bat detector can be
adjusted and it is possible to distinguish the different bat species by the
frequency of their calls.
For more information on bats try
The Bat Conservation Trust | 