Take a stroll on one of the lighter, still evenings we are now enjoying, and you’ll likely see bats fluttering overhead in the gloaming. They are common across London, particularly over any reasonable body of water. The Serpentine in Hyde Park or the boating lake in Battersea Park, for instance, can have dozens of common pipistrelles and the larger noctules wheeling over the water at dusk.
You’re most likely to see a common pipistrelle in your garden, not least because they roost under the eaves of houses. They catch and consume their prey — mosquitoes, midges and other annoying things — while in flight. They’re tiny: only about six grams and with a wingspan of 20cm or so, and have the most erratic flight.
Others, such as the natterer’s bat, which is easiest to see in Highgate Wood or Chiswick, can hover in the air. The noctule is a more direct flier, and a larger bat with a wingspan of 40cm. It too is happy in central as well as Greater London.
Many people claim to be freaked out by bats but it’s hard to watch them properly and not feel just a little elated. They have such an erratic flight, fluttering and dipping down so fast that sometimes you doubt you’ve really seen one. Watching them flying over a back garden on a quiet evening when the dew is settling on the grass and a blackbird is still singing in a blossom tree is a quiet pleasure — and it’s one you do not have to be in the country to enjoy.
I say a quiet pleasure, but bats are actually incredibly noisy. They yell to one another constantly. It’s just that their calls are outside our range of hearing, so standing under a cloud of bats is as silent as being entirely alone. If you want to hear them you’ll need a bat detector, which looks and sounds as though it would be more at home in an Adam West film.
Fancy kit or not, an evening with bats on the wing is as much a feature of the warmer days as the first swallow of the year. Make sure you take a few minutes to stand still as it grows dark.
