Published: Apr 26, 2017Tiny flying mammals that shout to see - bats are amazing, but they need our help to navigate this busy world.
Every night, the skies of Britain come alive with tiny, flying mammals. They roost in trees, barns and caves. They are the only flying mammal, and amongst the very few with the ability to echolocate. I am, of course, talking about bats. Bats makes up almost a quarter of the mammalian species found in the UK, and are perhaps the most bizarre of the lot.
Bats use sound to see. They shout extremely high-pitched calls which reflect off objects in their environment. They listen to the returning echoes to build a picture of their surroundings. Despite their tiny size – most are about the size of your thumb – bats are voracious predators of insect pests. The common pipistrelle is thought to eat up to 3,000 insects in a single night!
In the UK, Devon is the home of the bat. More species are found here than in any other county. They live amongst us - along our rivers, within woodlands, farmland and suburban areas. Unfortunately, they are incredibly threatened. Development puts the habitats they use to forage and travel along under significant pressure. This is bad news for bats, whose populations grow extremely slowly. Female bats give birth to a single pup every other year, with most living for over 20 years. This means they find it very difficult to counter negative change quickly.
Why is development a problem and what can we do? The main threats from development are loss of habitat and disturbance from light pollution. We live on a planet with a growing population, new houses, supermarkets, and roads must be built. But I think we can come to a compromise.
There is a consensus amongst conservationists that wildlife populations must be connected across the landscape to survive. Why? Let me present a scenario: We live in houses, with food in our fridges. When we need more food, we drive on roads to the supermarket. When we need to give birth, we drive on roads to the hospital. We’re connected. Bats are exactly same. They live in roosts and travel along our farmland hedgerows, rivers, and tree lines to places where they can find food. Every summer, females travel to maternity roosts to give birth. Bats, like all wild species, need to be connected across the landscape if they are to live within that landscape.
The designation of dark corridors in areas of development is part of the solution. Dark corridors allow bats to continue to fly undisturbed and reach essential areas where they can feed, roost and reproduce. The problem is nobody really knows how big they need to be. If they are too small, then bats might not use them. My research at Paignton Zoo focuses exactly on this issue.
Global Lighting Technologies have kindly donated me LED lamps that I am going to use to simulate streetlights. These will be placed at different distances apart to create different widths of dark corridor. A bat detector then records the calls of bats travelling through. That will tell me which size of corridor bats prefer.
We have a responsibility to look after the native species that live at Paignton Zoo, including bats, and to make sure they are connected to other wild habitats in Devon. Indeed, one of the primary responsibilities of zoos is to prevent the global decline in biodiversity. Making sure that wildlife has space to connect is part of the solution. I hope my research with bats will go some way towards making that happen, so that they can continue to thrive in our landscape.
Luke Romaine, Ecology Research Placement Student