Nature Features

Green space along the River Colne

It all started a couple of years ago when members of the River Colne Project, a group of volunteers working at improving green spaces along the river bank, went out to look for water voles. Their research revealed that there wasn't a single water vole but, as Project Officer Mick Smith tells us: "We did find the valley was a wonderful place for bats. It was a shock, it really was."

On the drawing board: a grand new home for bats!

Population distribution maps were produced indicating not only where bat numbers were low but where there might also be barriers stopping them extending their range. These results got Mick thinking about how more roosting opportunities might be provided for the Colne Valley's bats: "A lot of the trees are beech and sycamore and they have very smooth barks - not the peeling bark or the cracks and fissures or holes that you usually get with oak and ash. These little holes and nooks and crannies are what bats like so we thought that might be one of the reasons why there aren't so many bats in these areas."

Bat detector Mick Smith

However, Mick felt something more needed to be done and, as he explains, it needed to be something that wouldn't just please the bats: "I wanted to come up with an idea that would have some serious benefits for bats but would also grab the imagination of funding committees sitting around the table looking at umpteen funding applications." The answer was a bat tower: "No one's done anything like it before. In America some people have made square structures out of breeze blocks, the ugliest things you've ever seen in your life, so we didn't want to do that." And the bat tower also had to fit in with its surroundings and, as Mick points out: "There's lots of mill chimneys...We wanted something that would reflect  the history of the area. That's how we came up with the mill chimney. It's a very simple structure. It's just concrete manhole rings stacked on to each other which form the internal chamber but we are going to clad it with stone so it looks a lot nicer."

High rise homes also available but only for bats!

There will be different types of entrances for the bats to use and there will even be a tunnel from the river to allow the bats to fly right in: "Some bats like to stand, crawl or go into roost. Some bats like to just fly out again. Having the tunnel will double the amount of bat species that the chimney will attract...It's providing as many possible different conditions for as many different species of bats as you can within one structure."