October 16

One of our neighbours in the village recently found a bat roosting on their window-frame.  Unfortunately, it was roosting on the inside of the frame.  It’s not clear how it got there, but it’s likely that it chased an insect into an open window and then couldn’t find its way out.  Calling the author of nature notes didn’t resolve the situation as he only took photographs and made sympathetic noises.  Calling Karen Hammond of the Sussex Bat Group was a much better idea as she had the appropriate gloves and knows a lot more about bats.  She captured the bat and identified as a male brown long-eared bat before releasing it away from the house.

Brown long-eared bat - Plecotus auritus

Karen is the Volunteer Manager at Bodiam Castle and deals with all bat-related issues there.  She is also a registered bat-carer.  That last fact is important as all bats are protected species and anybody who handles them must have enough knowledge and an appropriate licence.  (There is also the slight risk that bats can carry a rabies-like virus – hence the gloves.) Karen also gives very interesting talks at Bodiam Castle occasionally and I can highly recommend attending one. 

In spring bats make a roost where the females can give birth and suckle their young until they are weaned.  Unsurprisingly these are called maternity roosts.  Normally, for most bat species, the males are not welcome in these roosts, but in the case of long-eared bats males are tolerated there.  Autumn is the time when bats mate, something that must be accomplished before hibernation, so maybe this lone long-eared bat had other things on its mind.

Bats are remarkable creatures, they are very agile as they dart about catching insects on the wing.  We often see a couple of bats flying round the garden at dusk and it is always a pleasure to watch them swooping about.  Apparently the brown long-eared bat is even more agile than most other species and it can hover and take insects from vegetation.

The long ears (in this case, almost as long as its body) are mainly to help with echolocation, the means by which the bat detects its prey.  It sends out pulses of very high frequency sound which echoes off the insects and tells the bat the direction and distance of the insect.  Possibly as a result of its long ears, the long-eared bat can also hear the lower frequency sounds, which allows it to hear insect movement on leaves and branches etc.

If you find a colony of bats roosting in your house rather than just one confused individual, then it is no good calling out a bat expert as it is illegal to disturb or destroy bat roosts in the UK, or to block access to them.  This is a protection covered by both UK and international laws.  The protection is there because bats are generally in decline due to loss of suitable roosting sites as well as the decline in their insect prey due to intensive farming methods used since the end of the Second World War.

Personally, I’d be delighted to have bats roost in our house and I am considering putting up a bat box to try and attract them.  That may mean that we get fewer moths in the garden, but as long as it’s in a good cause…

Away from bats, and more towards their prey, I found a tiny, beautiful and very unusual insect in the garden recently – an Andromeda Lacebug.  These insects are associated with the shrub Pieris japonica otherwise known as Japanese Andromeda and were introduced into the UK from Asia via the plant trade. 

Andromeda Lacebug - Stephanitis takeyai 

For more details about how the bug got its name see www.pettnats.blogspot.com.