The Mexican Free-tailed Bat (or Tadarida brasiliensis) is your everyday, medium sized bat. There’s nothing all that special about them. They are about three and half inches long and weigh less than half an ounce (0.43oz). As far as bats go or any other mammal, they are the most numerous in North America and generally look like what you would expect a bat to look like – a little doggie with wings!
Yes, they are very very cute, and so soft and cuddly you just might take one home with you – I did. But I’m getting ahead of myself. What I want to write about is the large colony that lives under the freeway between Sacramento and Davis, California: The Yolo Causeway Colony.
I’ve heard about this colony before, but I’ve never gotten a chance to see the bats at flyout. Though not as large as the one down in Austin, Texas at the Congress Bridge, it is still quite impressive with an estimated population of 150,000 bats.
Driving home yesterday from Santa Rosa, I got to see the critters first hand. As I drove east along Highway 80, I encountered light traffic through Fairfield and Vacaville. Cars slowed down almost to a stand still once I reached Davis. There didn’t seem to be an accident so I figured Davis was just getting populated. But I think I found the real culprit when I got on the Yolo Causeway.
The Yolo Causeway is an elevated part of Highway 80 that spans a large, flat water basin that is flooded in the winter and farmed during the summer. As I traveled over the causeway, great black waves of smoke drifted from the fields below and high up into the blue-pink sky. I thought the farmers were burning the rice fields awfully early in the season and concentrated on the braking lights in front of me.
I then noticed the flickering flight pattern of one arm of the ‘smoke’. Slowing down, I looked more closely and realized we were all staring at bats. Hundreds of thousands of bats. They were AMAZING! People, though surely annoyed with the halting traffic, pointed and smiled. Kids jumped in their seats as we drove by their flyout point to see the critters just a little bit better. I’m glad that most folks on the freeway recognized such a privileged sight.
I resumed my journey, my heart lighter for having witnessed majestic nature. If you ever get a chance to witness a flyout, I highly recommend it. Not driving, of course. Take a tour from the Yolo Basin Foundation (booked for the rest of this summer). You can see ’em from below the causeway rather than on it.
To learn more about bats in Northern California, go here: Northern California Bats.
Oh…you may be wondering when I took a bat home with me…
Back when I worked for California State Parks, our office happened to be a small settler’s cabin on the shores of Lake Tahoe – one very old cabin. It also happened to have a small colony of Myotis lucifugus or the Little Brown Myotis living inside the attic. One spring, the colony had a bumper crop of babies. They were everywhere, crawling out of the woodwork during the day. There were just too many of ’em. The colony mothers were undoubtedly inundated with the baby critters, leaving some to their fate as they roamed outside of the colony looking for food, shelter and comfort. All these little baby bats were just too cute to leave out to die, so I and a colleague took two home.
In those days, I biked to work everyday and everyday my little brown bat rode with me. As Tahoe mornings can be cold, even in the summer, he would crawl under my shirt to a point just between my shoulder blades. It was the farthest away he could get from the icy wind pummeling from the front as we cycled down the river path. As he grew, every now and then he would stretch and flutter his wings out beneath my cycle shirt, eager to take flight.
Eh, isn’t it funny that my current WIP features a woman with wings and is called la murcielaga? 😉