Tottenham Marshes Bat Walk

May 31, 2008

About half a mile from my home in Walthamstow, the streets and industrial units all come to an abrupt halt. The cityscape is replaced by the waterways and marshes of the Lea Valley Park Authority.

The park runs for 26 miles from the banks of the River Thames out into Hertfordshire and is dedicated to nature conservation and recreation. On a casual afternoon stroll you’re likely to share the park with people running, biking, canoeing or boating.

But at night, the park becomes a different place when the nocturnal creatures – like bats – come out to feed.

Curious to know more, Bronny, Del, Sarah and myself decided to join a ‘bat walk’ – and weren’t entirely sure what we’d let ourselves in for….

Del: not sure what’s he’s let himself in for….

Our guides for the evening, Jeanette and Lisa immediately, and unexpectedly, plied us with tea and hob-nobs at the visitor centre. Lisa is the park ranger, and Jeanette a volunteer from the ‘Lea Valley Bats’ and was our bat expert for the evening.

Bats, bats, bats….

Jeanette gave us a intoduction to the various types of bats we might see and would hopefully hear with the help of bat detectors.

You can detect bats, but not Meatloaf with this device

Bats orientate themselves in flight, and detect their prey by sending out a sonar know as ‘echolocation.’ This is where the bat detectors come in, because apart from some young children, these sounds aren’t audible to the human ear.

Bronny and Sarah: having fun twiddling knobs

As dusk encroached, about a dozen of us headed into the marshes.

If I was a bat, I’d like to live around here too

The marshes are an oasis of peace and tranquility in the middle of a busy city. Much of this grassland covers debris from WWII bomb sites, and became a protected area in a bygonne era when central and local government believed that creating such natural spaces were essential to the well being of their citizens.

Bat alley comes alive

Jeanette walked us down to an avenue of trees called ‘bat alley’ explaining it was unlikely we’d hear any bats yet at this early hour. But much to her delight, our bat detectors suddenly fizzed to life and in the half light we caught glimpses of the darting bats.

Jeanette, identifying the bats

I had been ‘so-so’ about the whole bat experience up until this point, but seeing and actually hearing the bats and the sounds of their remarkable ‘echolocation’ was an exhilarating moment.

Tuning into hear the bats ‘echolocation’ signals

Different species of bats can be heard on different frequencies, and we were able to identify the Noctule and Pipistrelle.

Lisa: a ranger, but doesn’t look anything like Chuck Norris…..

Lisa, the park ranger of five years told us more about the work in the marshes. Nearly all the conservation work is only made possible by volunteers, who’ll turn up to weed, plant or build on weekends.

Burn baby burn… the lights that hurt the bats

A growing problem for the bats and other nocturnal creatures on the marches is the number of lights on the parks borders that blaze away during the night.

They draw insects – the bats food – towards them, so the bats have to follow. This is extremely unpleasant for the bats. I’m reminded of the later stages of ‘Lord of the Rings,’ where Frodo has to enter Mount Doom……

Our friends, the bats. Watch them while you can…

Half a mile from bat alley, a new housing development is springing up. Across the other side of the marshes, a gargantuan development of 2,000 flats is planned. This latter project is against the local communities wishes, and will soon concrete over well-loved playing fields.

Activists cite many reasons why this development is poorly planned, including the lack of parking space and any thought for where the new residents children may go to school.

Another reason, is that it will be built right on the border of the Lea Valley Park and the lights from these new homes will illuminate a great swathe of the park where the bats once roamed. People have to live somewhere….. but so do the bats……