Bats are dying from the bends

There is such a thing as a cute bat.

When I was hunting for jobs this spring, a search with “animal” in the subject field returned a listing for a position as a Field Biologist.  One of the requirements was familiarity with native California birds.  Thinking I could use my ornithological bent for more than a hobby, I was intrigued…until I read on: the position included monitoring, identifying and tracking all wildlife found injured and killed beneath wind turbines. My heart dropped.

 

Bats, a flying animal near and dear to me, are at greater risk of death by wind turbine than birds.  Despite the large number of bat carcasses found near turbines, the recovered bat bodies have no external injuries or visible cause of death (in contrast to birds which are killed by direct contact with the blades).  Bats adequately detect and avoid contact with turbines using sonar, but are dying from an unknown secondary impact of flying near windmills.

 

Anywhere that appears dark and safe

One way to have a close encounter with a bat: hang your laundry outside to dry overnight.  If you get lucky, like Abbie Hawkins, you may find a baby bat nestled in your bra the next morning.

While a bra may seem like an unusual place to find a bat, a spokesperson from the Bat Conservation Trust noted that bats “roost anywhere that appears dark and safe”.  Good to know.  And now, I’m off to do some laundry.

Zigzags of bat flight

As a child I was intrigued by all things nocturnal, bats in particular. Given the difficulty I had – as a typical diurnal child – spotting bats in daily life, much of my understanding of their habits and appearance was left to my imagination.

When I first saw the wee tree bats in Costa Rica, they were clinging to a tree alongside the Colorado River. I was amazed at their miniature size and delicate vulnerability, exposed as they were to daylight and binoculars. Several days later, while taking in the sunset near Corcovado, I happened upon a pair of bats making a circuit around and through a cabana. This seemed to be their waking ritual, as every evening I would sit in the same place to watch the sunset and they would suddenly appear at dusk, fly several rounds about the cabana, then flap away as the sky darkened.

wee tree bat

On a separate trip later that same year, just outside Lassen Volcanic National Park, I watched the moon rise over an eastern range. Perched atop a pile of lava rocks I felt gentle, irregular whisps in the dusky air. Zigzags of bat flight flew near my head, then away, then to a rock, then back to where I sat. I watched the unpredictable circuit with delight, feeling both appreciation and apprehension (which bats are vectors for disease in humans?) to be so near these creatures. For once my tendency toward immobility served me well; I imagine bats would not approach and investigate me as carefully were I moving around.

Given my fondness for bats, I was excited when I came upon this article in the Perspectives section of the June 24, 2008 issue of PNAS today.  In the piece, neuroscientists Nacham Ulanovsky and Cynthia Moss present research findings from behavioral and neurophysiological studies of bats. Their data have interesting implications for understanding “the behaving brain across species”, – Homo sapiens included – based on how bats process environmental information acquired during echolocation. I also found a review of the article on Think Gene, where a user’s comment linked to a documentary about a blind boy who uses a form of echolocation in daily life. Lacking the rich information gathered using sonar, our attempts at sound navigation may not compare to that of bats. Even so, I’m curious to see how including additional auditory information in daily life would alter my experience.

Unique sonar signatures

I <3 plants, and occasionally daydream about anthropomorphizing the characteristics of certain genera and species. To be honest, I wrote a story about plant voices a while back. I’ll dig it up tonight and post it so you can see what I’m talking about.

Scientists are curious about how plants sound, but in an entirely different way. Rather than creating fictional personalities for plants, scientists in Germany have found a way to visualize the sonar echoes returned by plants. The idea behind this being fruit bats, who locate specific fruit-bearing plants with sonar, may be identifying plants by sound. The researchers found certain plant species indeed have recognizable, unique sonar signatures and are learning how bats interrogate and “communicate” with plants. This is a language I want to learn!

Here’s a link to a brief digest of the research on Science’s website, and a link to the full PLOS article.