Canals and bats might not be the most obvious mix. Yet according to Tim Mulligan, an ecologist with the Canal & River Trust, the near-total night-time darkness makes canals a refreshing route for the nocturnal.
Bats are just one of the stars of this surprisingly abundant ecosystem, alongside crayfish, terrapins, mitten crabs and mink. Daylight timing means Tim and I are out today spotting kingfishers instead of the spookier critters. There’s a kingfisher burrow just off the Limehouse Basin, the perfect place to start.
Tim and his team look after the wildlife on London’s waterways, a remit which includes everything from these birds, to invasive exotic weeds, to the tiny snails we’re now fishing out with Tim’s trusty net. (We put them back afterwards.) Tim’s job is all about caring for the water’s residents, which means he knows a lot about the more colourful characters – like the seal who rocks up to Billingsgate Market for breakfast, or the psychotic swan who drowns Canada geese in Camden Lock for kicks.
Aside from helping me with bird-watching and snail-spotting, Tim is keen to draw my eye to some of the threats faced by these waterways – such as the looming high-rise developments above, which block out the sunlight necessary for bottom-of-the-food-chain daphnia to develop. There’s pollution, too, hence the Canal & River Trust’s ongoing initiatives to get London residents litter picking, as well as the in-house efforts to build water-filtering floating ecosystems. These provide the triple whammy of flowers for pollinators, habitats for underwater animals, and a natural water filtration system which wards off pesky duckweed (that’s the green stuff you often see on the surface).
That’s not to say it’s all rubbish – some of the canals’ more wily residents have made the most of their urban existence. ‘Eels love abandoned tyres,’ Tim says. ‘Every time we’ve tried to remove one, it’s been full of eels.’ Thankfully, our walk is tyre-free – although I’m pretty sure I can hear some bats under the bridge where we end our trip. I think I’ll stick to land for now. Bobby Palmer