Bats: and why to love them

But in reality these charming but funny looking gentle and widely misunderstood creatures are an important part of our ecosystem and indicators of our biodiversity.

We have 18 resident species, accounting for more than a quarter of our mammal species, and far from sucking blood, all of ours only eat insects such as moths, midges and beetles. Flies are an important food source for many, and they consume pesky midges and mosquitoes. They play an important part in insect pest management.

In a study published in 2011, researchers in North America analysed what the economic impact would be on agriculture if bats were lost. They found it to be in the $3.7 to $53 billion a year range. Bats’ benefits on pest management within corn growth in the US, rice growth in Spain and vineyards in Portugal have been shown to vastly reduce the need for pesticides.

Our largest bat, the Noctule is usually the first to appear in the evenings, sometimes even before sunset. Image: Nyctalus noctula = https://commons.wikimedia.org/wiki/File:Nyctalus_noctula.jpg

Sadly no such studies have been undertaken in Britain, where bat populations have declined considerably over the last century, due to a number of different reasons including agricultural intensification and pesticide use.

Bats’ roosts are protected under UK legislation, but their foraging sites are unprotected, which makes them vulnerable to land use changes. The impacts of agriculture can have a dramatic effect on bat feeding sites. Intensive farming practices and countryside changes mean that bats’ natural habitats such as hedgerows, woodlands and ponds are declining and fragmenting. They use a variety of landscapes or habitats throughout the year as they feed, roost and travel. These include hunting grounds or foraging habitats to find food and commuting habitats to travel between roosts and foraging sites.

Studies are currently taking place to find out more information about which of the current Agri-environmental schemes, if any, are beneficial for individual bat species. Grass buffers in arable fields, hedgerow restoration, floristically enhanced margins and wild bird seed mixture plots all seem like good starting points for addressing the issue.

As their natural habitats become scarcer, our gardens, allotments and parks are also playing a more important role in securing a future for bats. Many of the actions you can take that will help insects and other wildlife will also benefit bats.

What can I do?

Habitat management

Keep an eye open for roosts in buildings and trees. Always check for the presence of bats in holes and crevices before working on trees. Old or ‘veteran’ trees are especially valuable to bats. Avoid felling and leave dead wood wherever possible. Holes, splits or loose bark can be used by bats at all times of year.

Restore and create hedges, woodland edges and other linear corridors to provide a continuous matrix of flyways for bats. Protect sheltered ponds, marshes, ditches and streams. These actions will have wider benefits for many species of declining farmland birds and mammals.

Boxes should be put as high as possible in sheltered sunny places

Planting

Any flowers that attract insects will in turn attract bats. The wider the variety of flowers and the longer their flowering season is the better for our batty friends.

In June especially, insect abundance is key to bats’ survival. Mother bats feeding their pups will be using more energy which in bat terms means they need to eat more insects.

Native plants and trees tend to support far more species of insect than hybrids or exotics, and by planting a mixture of flowering plants, vegetables, trees and shrubs, you can encourage a diversity of insects to drop in and refuel from spring to autumn.

Tall, pale or night-scented flowers are especially attractive to the nocturnal insects that bats eat. Hemp agrimony, Evening primrose and Night-scented stock are particularly good at attracting these insects.

In the garden

Bats are primarily nocturnal, resting during the day and emerging around sunset to feed. so reducing any artificial lights such as street lights, garden security lighting or decorative lighting on homes and trees, can be a great benefit.

Although some fast flying species do hunt insects around lights, most do not and artificial lighting can act as a barrier, which means bats may not enter lit areas or may even abandon roosts. Reducing artificial lighting such as street lights, garden security lighting or bright ornamental lights on homes and trees, can be a great benefit.

Another problem encountered by bats is cats. Bringing your cat in for the night half an hour before sunset will allow bats to emerge from their roosts undisturbed. This is especially important at this time of year when bats are rearing their young. They will also be able to return at dawn undisturbed.

Building a pond can be another great way to encourage bats, alongside other wildlife, to visit your plot. Ponds support the aquatic larvae of insects such as small flies, which are a favourite of pipistrelle bats. Avoid goldfish, as they eat the insect larvae.

A compost pile or heap can create the perfect habitat for some of bats’ insect prey. Log piles in a damp shady spot will do the same.

Installing a bat box will drive them batty with joy. Ideally, several boxes should be put up facing in different directions to provide a range of conditions. Boxes should be put as high as possible in sheltered sunny places. On buildings, boxes should be placed as close to the eaves as possible. Some bats use a tree line or hedgerow for navigation. Putting boxes near these features may help the bats find the box.

To find out more about bats what you can do, visit the Bat Conservation Trust website: www.bats.org.uk