As autumn comes and the garden quietens down you could do worse than start planning for next year and on ensuring your garden is a hive of wildlife activity should be on your roadmap. If it is then don’t forget bats. They are often ignored, even by the most enthusiastic wildlife gardeners, but they are good indicators of the health of the environment because of their broad range of needs and their sensitivity to changes in their surroundings. So this is a good time to think about planting even simple souls such as hawthorn next spring.
Bat populations declined in recent decades as their homes and feeding grounds disappear. But you can help by turning your garden into a haven for bats, knowing that while there’s no guarantee they will visit, it will be an environment good for many wild creatures.
Central to good gardening for bats is the encouragement of lots of insects from early spring through to late autumn. All 17 varieties of native bat feed on insects, and as flight uses a huge amount of energy they eat a lot. Providing for that need is most critical in the summer, when pregnant and lactating mothers (yes, bats are mammals like us) are eating for two. As different bats have different food preferences, a range of insect species to choose from may help to encourage more than one species into your garden.
The Bat Conservation Trust (BCT) tries to encourage as many people as possible to welcome bats into their gardens. For the last four years we have attended the Gardener’s World Live event at the NEC, and our stand garden, showcasing bat friendly plants, has won a Royal Horticultural Society award each year. It’s been encouraging to find how enthusiastic many people are about bats; so often at the stand the first question has been “How can I encourage bats to my garden?”
After hibernating during the winter, bats need to replenish their fat reserves in the spring, and similarly need to stock up before hibernation in the autumn. Look around other people’s garden to see what is in bloom outside the usual season, and add those to your own, from Aubretia and Bergenia in early spring through to ice plants, sedums and asters in autumn. Although native plants are attractive to native insects, many non-native plants are important to pollinating insects too. We grow flowers for their appearance and scent but these have no direct function in a plant’s life. A plant is interested only in producing seed in order to take it on to the next generation. In the UK nectar and pollen are offered as bait to insects, inviting them to visit the flower; pollen is carried inadvertently from one flower to another on their body, so ensuring fertilisation in the next flower of that type visited. Scent and colour are used in different ways to advertise the presence of that pollen and nectar.
Tall and/or pale flowers are more obvious to insects at dusk when bats will be foraging. Single flowers are less confusing to insects than double ones. Flowers with a flat head like Achillea or wild carrot provide ideal ‘landing platforms’ for tiny insects. Herbs and aromatic flowers attract insects. Note the length of the pollen tubes on flowers; their length will decide which insects are able to feed on them. The more diverse the flower shapes, the more different insects that will come to feed. Daisy-like flowers- Rudbeckia, Marguerites, Echinacea and many more - have many short florets where tiny short-tongued insects can feed, whilst only long-tongued insects like moths are able to feed on the long pollen tubes of honeysuckle and tobacco plant.
The life cycle of insects is complicated. Most insect larvae live and feed quite differently to the adults so we need to provide food for these too. A corner of the lawn left uncut for grass to grow long is good for some insect larvae. A small native tree or shrub such as hawthorn or silver birch will feed many more, and even a small pond is a real bonus for bats, as many insects – midges, gnats and other tiny flies- have aquatic larvae. Flowers suitable for pond edges and marshy areas include meadowsweet, water forget-me-not and water mint.
The most likely bat visitors are two pipistrelle species, our smallest bats, looking about sparrow sized as they fly. But this is deceiving. Their wings, on a framework of arms and extended fingers, are very large, yet when they are folded one of these little bats would fit into an ordinary matchbox. As it dodges around the garden chasing tiny insects, it homes in on them with an amazing sonar system - echolocation. Only by using a bat detector can we ‘hear’ those very high calls, and discover which type of pipistrelle it is.
Finally, add a seat or bench, sit back and relax and enjoy the sights and sounds your garden will now have to offer! And when you see bats, do enter them on our big bat map (https://www.bigbatmap.org/) and if you want to find out even more about our furry flying friends then join your local bat group and BCT https://www.bats.org.uk/pages/join.html - there is also more information about gardening for bats on the same site
If you find an injured or grounded bat in your garden please call the BCT’s National bat helpline on 0845 1300 228.
Kindly written by Molly Patterson and Shirley Thompson of the Bat Conservation Trust. The copyright is theirs.