Essex Wildlife: Bats

At Greenstead Farm, we are very fortunate to live in an area and environment where, shortly after sunset, we are treated to an aerial display of small winged mammals going about their evening hunt for insects and food.

For many years, and mainly thanks to Bram Stokers "Dracula", bats have been associated with Halloween. The story is based around vampires, which are of course a superstition, which date back hundreds (if not thousands) of years. In the story the vampires were able to shape shift into bats which is why, at Halloween, bats are perceived as being dark and mysterious, just as any other Halloween creature is portrayed.

So now we’ve heard all about the myth, let’s take a look at some interesting facts surrounding bats.

In the UK, we are lucky enough to have 17 different types of bats but only 10 species are commonly seen in Essex. They range from the tiny Pipistrelle bat (pictured) which is just a few centimetres long, to the larger Noctule bat, which is still smaller than an adult's hand!

The body of the smallest bat found in the UK, the Pipistrelle, measures only about 4cm long and weighs around 5 grams - that's less than a £1 coin! In comparison the UK's largest bat, the Noctule, is almost twice the size and weighs up to 40 grams. Even the Noctule is tiny though compared to the world's largest bat, the Kalong (also known as the Japanese flying fox). It lives in south East Asia and feeds on fruit. With a wing span of almost 2 metres, it's the biggest bat in the world!

All bats native to the UK eat insects. Each species has its favourite insects, hunting them in its own special way. Most are caught and eaten in mid-air, though it is sometimes easier to hang up to eat larger prey. All bats have very big appetites because flying uses up lots of energy. The tiny Pipistrelle can eat over 3000 insects in a night!  In winter, when there are fewer insects around for them to feed on, bats go into hibernation to save energy. One of the reasons bats are in danger in the UK is because there are less insects around for them to feed on.

A bat’s home is a 'roost.' They roost in different places at different times of the year. In the winter, when bats go into hibernation, they usually move into caves or disused mines or tunnels, where the temperature is cooler and they won't be disturbed. For several weeks in summer, female bats live together in a 'maternity roost', choosing somewhere warm to have their babies. They stay here until their babies are able to fly and feed themselves.

Many people think bats are blind, but in fact they can see almost as well as humans.
However, at night, their ears are more important than their eyes - they use a special sonar system called 'echolocation,' meaning they find things using echoes.

As bats fly they make shouting sounds, which are too high for most humans to hear (although sometimes children are able to hear them). The echoes they get back from their shouts give them information about anything that is ahead of them, including the size and shape of an insect and which way it is going.

Ever wondered why bats hang upside down?

Well, if bats hung by their thumbs they would have to let go before spreading their wings. By hanging upside down they are able to spread their wings ready for take-off. They also have a good clear view for both seeing and hearing before flight.

To stop them falling down when they are asleep, the tendons in their legs and feet are designed so that the weight of the bat causes the toes and claws to grip the foothold in the roost firmly.

In most mammals, including you and me, the knees bend forwards. This would be awkward for bats hanging against a surface, so their knees bend the other way.

Did you know a bat is a mammal just like you and I. They have hair or fur on their bodies like many of our pets and are warm-blooded. A baby bat feeds on its mother's milk for at least a few weeks after it is born but bats are the only mammals that can fly. A bat's wing has very similar bones to the hand and arm of a human, with skin stretched between the very long finger bones and the body to form the wing membrane.

The Bat Conservation Trust has a great website if you want to know more about bats and how you can help conserve their species - visit the site here.

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