Bats are vital to the health of our natural world and economy. Although we may not always see them, bats are hard at work all around the world each night – eating tons of insects, pollinating flowers, and spreading seeds that grow new plants and trees.

Bats in the UK

There are currently over 1,400 species of bats worldwide (that’s around a fifth of all mammal species), with more still being discovered!

The UK is home to 18 of those bat species, 17 of which are known to breeding here (that’s a third of mammal species in the UK). Somerset is a great county for bats – we play host to a whopping 16 of the 18 UK bat species. In fact, two Special Areas of Conservation for horseshoe bats have been designated on Mendip. One of these, Mells Valley, contains an exceptional bat maternity roost, comprising about 12% of the UK’s greater horseshoe bat population!

So, why do bats matter?

Bats are a vital part of our native wildlife, occupying a wide range of habitats, such as wetlands, woodlands, farmland, and urban areas.

As well as contributing to species diversity, bats fulfil two important roles in the UK: they help control insect populations, and they are an ‘indicator species’. Over 70% of all bat species, including all UK bats, are insectivores – they feed on a variety of insects, bugs, spiders and arthropods. Insect-eating bats provide a valuable service for agriculture and are great for keeping bugs away from gardens. A single common pipistrelle can catch and eat around 3,000 insects each night!

Bats can also tell us a lot about the state of the environment, with 11 of the 18 UK bat species identified by DEFRA as ‘indicator species’. Indicator species are living organisms that can be easily observed and studying them is considered a cost-effective way to predict changes in an ecosystem.

Bats reflect the productivity of insect communities – because all UK bats are insectivorous, they are sensitive to accumulations of pesticides and other toxins (official DEFRA figures show that the total area of crops treated in the UK approximately doubled between 1990 and 2015), and changes in their abundance may reflect changes in populations of arthropod prey species. Pressures that bats can face also include landscape change, agricultural intensification, development and habitat fragmentation, all of which are relevant to many other wildlife species, which makes bats an excellent indicator for the wider health of the UK's wildlife.

What pressures do bats face?

Bat numbers in the UK have declined dramatically over the last century – four of the 11 mammals on the Red List of UK mammals at risk of national extinction are bats.

Although certain populations have started showing signs of recovery in recent years, changes in land use over the past few decades, such as building and development, more intensive agriculture and changes to farming practices, have led to impacts on bats through habitat loss, fragmentation, deterioration of water quality, the destruction of roosts and pesticides. Other threats include wind turbines and lighting (if they are sited on key bat habitats or near roosts) and even cat attacks. Changes in climate may also influence insect life cycles which may then affect when bats can feed.

What can you do to help bats?

• Spread the word – speak to friends and family about how amazing bats are!
• Make your garden more bat friendly – although conservation efforts have seen populations rise again, we can help bats out in our gardens too by encouraging a range of insects for them to feed on: somersetwildlife.org/actions
• Back our bats and say no to neonics by signing our petition: action.wildlifetrusts.org/page/142500/petition/1
• Take part in local bat walks or surveys – Somerset Bat Group runs many walks, talks, surveys and events throughout the year: somersetbat.group/events 
• Map bats in your local area on iNaturalist as part of Somerset Bat Group’s Big Bat Count, which is part of our Great Somerset Wildlife Count: somersetbat.group/bats/count
• Join a countrywide community of volunteers supporting the Bat Conservation Trust’s National Bat Monitoring Programme: www.bats.org.uk/our-work/national-bat-monitoring-programme 
• Consider supporting charities and groups working to protect bats – by donating or becoming a member, you can directly help to protect bats and their habitats for future generations to enjoy!