Following on from a reader’s plea to residents last month (FM September, Letters) to sign a petition in favour of safeguarding a hedgerow in Fairfield Gardens which is a known roosting site for bats – and of course with Halloween on the way – we asked Peter Land, our regular contributor on wildlife, for some more information about these nocturnal creatures. Here’s what he had to say.

Bats are mammals and surprisingly there are 17 breeding species of bats in the UK, but most of them are rarely seen and all species are in decline because of loss of habitat and a reduction in the number of insects, their major food source.

Bats are nocturnal, of course, and the best time to spot them is at dusk when they leave their daytime roosts which are usually in the eaves of buildings or churches, but occasionally in old tree crevices. Keen bat observers have special bat meters which can detect the high-pitched sounds of the hunting bats’ echolocation system, from which they can identify the particular species of bat.

I have only seen one species in Fairfield and that is the smallest of the bats – the Pipistrelle. However, there is another common species, Daubenton’s bat, which can regularly be seen hunting over the surface of water, and it is very likely that this species is present at the Blue and Green lagoons and along the Pix Brook.

Common Pipistrelle, Pipistrellus pipistrellus

Pipistrelles are the commonest and smallest of British bats. They weigh about 5 grams, have a body length of 4cm and a wingspan of 20cm. A Pipistrelle can eat up to 3,000 tiny insects in one night, which it locates using its built in echolocation equipment. During the summer females form maternity colonies where each gives birth to a single young in June or July. The young are fed on the mother’s milk for about four weeks, after which they are able to fly and forage for themselves. Mating takes place during July to September before the bats hibernate singly or in small numbers in crevices of buildings and trees and also in bat boxes. Pipistrelles live for about 4–5 years.

Daubenton’s bat, Myotis daubentonii

Larger than the pipistrelle, Daubenton’s bat has a body length of 5cm and a wingspan of 25cm and weighs around 10 grams. It is found across the UK and feeds mostly on aquatic insects, which it picks up near the surface of the water. Although it is sometimes found roosting in trees or buildings, it prefers caves and burrows near the water. This bat can live for up to 22 years.

Despite their fearsome-looking teeth, British bats are harmless to humans. There are no vampire bats in the UK. All UK bats are protected by law and can only be handled by a licensed professional. Unfortunately, domestic cats don’t know this – and since they are also nocturnal it is quite common for cats to catch bats when they are flying low.

Peter Land

If you would like to help protect bats in Fairfield you can find instructions for how to build a bat box here:  Choosing insect-friendly plants for your garden will also help to provide a plentiful food source for them.

Last month’s letter about bats can be found on our website and contains a link to the residents’ petition.