Bats and Wind Turbines.

A few months ago we bought a bat box. We haven't put it up yet though as it is very heavy and must go on top of a 5 metre pole! We have bats in the (no, not the belfry) old farmhouse buildings next to us, and we watch them in the evenings fall out from under the roof and fly off to consume as many mosquitoes and crop eating insects as they can! Apparently they can consume their body weight in insects! (I can do that with chocolate cake, but I'd never fly afterwards!) Bats are also responsible for the pollination of an amazing list of nut and fruit trees, as well as helping to promote the spread of new trees by pooing while they fly and letting the poo drop onto open ground! Unlike birds that poo in trees! I wanted to find a picture of bats to insert in my blog, so I happily Googled 'bat pictures'. Well, I realised that I should have been more specific as I ended up with a screen full of Batman and Robin in various poses (hmmmm!), old pictures of a pop group called 'The Bats', cricket bats, cricketers holding bats, cricketers running with bats, and a few real bats thrown in for good measure. See below!!

Real bats..thanks to 'africam'

That brings me to the wind turbines mentioned in the title. We have wind here, lots and lots of wind and there is a plan to build turbines all the way up the coast, we have several areas close to our village that have been earmarked. We need an alternate way of producing electricity and I am all for it. However, one thing that people are concerned about with regard to the huge turbines is the number of birds that may fly into the blades. At up to 100 metres high with blades up to 50 metres long, moving at up to 300 kms an hour, this is a distinct possibility/probability. Fair enough, we have several endangered and protected species including the Blue Crane and the African Oyster Catcher, and we need to protect them as much as possible. However, no-one has given a thought to bats. But, bats don't fly into things though, do they? Well, according to Canadian researchers, bat deaths due to the wind turbines outnumber bird deaths by a staggering 10 to 1.

A wind farm!

The researchers then discovered that very few bats had been hit by the blades or flown into them, but they had internal bleeding and damage to their lungs. The theory is this: the bats miss the blades, but then hit the air behind the blade where there is a drop in pressure. Their lungs then over-expand, causing the small blood vessels around the lungs to break. They then literally drown. The condition is called 'barotrauma' and is similar to the ‘bends’ that affect divers when they surface too fast.

Some bat boxes

A smart bat box!

And here in South Africa? Research is still being done but it seems that turbines on high ground and riverine systems kill more bats, but not enough is known yet about their migration and activity patterns.

Bat boxes at Berg 'n dal, Kruger Park

The problem is, is there time to find out before the blades start to turn?