Friday, June 13, 2014

Bats!



For the past couple nights, I have been spending time with bats.  Yes, the popular Halloween images that everyone is familiar with.  They really are misunderstood creatures and are not a danger to humans or other animals.  They actually provide an important service for humanity – the consumption of insects.  In the case, in this area of Texas, they feed on moths that produce larvae that infest corn.  They can eat up to 40 moths per night.  Figure out how many that would be if you had a couple million bats going out to hunt every night.  The farmers love them.  There are no vampire bats in the U.S. – those are reserved for South America and places like that, so we're not talking about that kind.

The photo above is the entrance to an old railroad tunnel, which was abandoned in the early 1940’s after about 30 years of service.  Every year, the Mexican free-tailed bats migrate up here for the summer, starting in May.  The females arrive pregnant and when they are ready to deliver the baby that will weigh about 1/3 of her own weight, they will find caves in this area to deliver.  The babies require very warm temperatures or they won’t survive, they like it around 100 degrees or so and that won't happen in this tunnel since there is air flow through it.    The mother and babies will all spend about 5 weeks there and then return to places like this tunnel or under bridges in other areas. 

If you look directly into the tunnel before dark, you can see the bats moving around in there, but the real show starts about dusk.  At first, you’ll see a few bats fly out, then you’ll see more .  Soon, you will see a continuous stream of them, seemingly coordinated, fly out to create a counterclockwise vortex of swirling bats.  The area will be thick with them.  After they have gained enough speed and altitude, you’ll see them leave this vortex and fly off into the sky in search of their food.  Since there can be as many as 3 million bats in this tunnel, this continues for an unbelievable length of time. 

Last night, a large group of people gathered on the benches on the side of the area above and to the side of the tunnel.  I wanted to be as close as possible, so I was sitting right next to the fence.  This spectacular event lasted over a half hour and the air was continually thick with these critters.  They are so fast that it was impossible to make out any detail of an individual animal, you were just able to get the impression of a continual flow of them.  If you listened closely, the sound of their wings beating the air sounded similar to a distant stream flowing over rocks.  When the ranger told us it was time to leave, they were still coming out of the tunnel. 

During all this, I was watching the ones closest to me, some zoomed by within a few feet.  There were obstructions for them to get around, such as the fence, and a few misjudged and landed on the ground on the other side of the fence, but got right back up and into the mix.  One didn’t quite make it safely over the fence, but tumbled to the ground right at my foot, brushing my ankle lightly as he fell – but he was up and gone in a second. 

It was a great privilege to see this event and I hope I’ll be able to see more of them in other areas.

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