Marston Forest – Bats in Trees

Bats in trees

why woodland is so important to these nighttime visitors…

Bats are one of the most fascinating but misunderstood animals in the world. For many people, they conjure up images of evil spirits and bloodthirsty vampires. Probably the most famous reference to bats in popular culture is in Bram Stoker’s Dracula. First published in 1897 but made famous by the original film in 1931, the shapeshifting Romanian aristocrat has probably done the most to cement negative images of bats into people’s minds. In reality, this perception of bats could not be further from the truth, but their shy and secretive nature has meant that old myths die hard. In fact, out of the estimated 1,300 species of bats in the world the majority eat insects with others having found to eat fruit and nectar. Only three species of bat feed on blood and are all found in South America – not Transylvania!

In the UK, bats feed exclusively on insects, ranging from small biting midges to large beetles such as cockchafers and dung beetles. Out of all the small fluttery shadows that you are able to make out at sunset, the pipistrelle is probably the bat you’re most likely to see as it is often flies around street lights and in gardens. Although only weighing around 5 grams, pipistrelle bats can eat up to 3,000 insects per night!

In addition to the tiny pipistrelle, there are a further 17 other bat species to spot in

the UK – making up almost a quarter of our mammal species. Some of the more common species that you might see include the brown long-eared bat, which has huge ears that are almost as long as its body, the pinkfaced Daubenton’s bat and the noctule, our largest bat.

The summer months are the best time to see bats, as this is when they’re most active. In June, female bats give birth, usually to a single baby bat, or pup. By August, the pups are able to catch insects by themselves, and the cycle starts again as mating season begins in September.

Bats live in roosts. They don’t ‘construct’ anything, like birds, but use structures that are already available to set up home, such as buildings, trees and caves. They move roosts a few times throughout the year, securing accommodation to suit their needs depending on the season. For example, pregnant female bats gather together and set up ‘maternity roosts’ in early summer, favouring warm, dry spaces in which to give birth. In winter, however, bats search for somewhere with a cool, constant temperature in which to hibernate. Underground caves are often used for this purpose.

Trees are also a popular roosting site used by three quarters of UK bat species. Older trees with crevices, holes, cracks and rotting wood are favoured as these provide the spaces bats need for roosting. Trees and woodlands are particularly important for bats as they support large numbers of insects, providing a steady food supply for bats.

Contrary to the saying ‘blind as a bat’, bats actually have perfectly good vision, but they use something called ‘echolocation’ to hunt their insect prey and also navigate around their surroundings. Echolocation is essentially a form of radar. The bat makes a very high frequency sound and then listens for its echo to return. By producing up to 200 calls per second, bats are able to build a threedimensional image of their surroundings that is accurate enough to pluck a spider from its web without damaging it. Bats have different calls and conservationists are able to use bat detectors to tune in and identify which bats are flying around.

Like many other wild species, bat numbers have declined because of a gradual loss of habitat, food sources and roosting sites. In recognition of this, all British bats and their roosts are now protected by law.

By planting and managing woodlands in the Forest of Marston Vale, we are providing new habitats for bats to help numbers recover in the future.