Hey Ranger: Bats as benefactors

These night creatures deserve appreciation rather than our fear

The “Hey Ranger” column written by employees of the Redwood National and State Parks  is published monthly. Today’s column is by Candace Tinkler, a ranger and chief of interpretation and education for the redwood parks.   

Twenty years ago I had a life-changing experience.  A national park scientist studying bats in Bighorn Canyon National Recreation Area needed an assistant to record data, and I was selected.

I hadn’t given much thought to bats before that evening. I was a little nervous as I helped him set up the mist net and then sat waiting on the desert rocks with only our headlamps cutting through the Wyoming night. When the first bat tangled into the ultra-fine netting, the researcher gently freed it with gloved hands and brought it over to be identified (a female pallid bat, in this case), and weighed while I recorded his findings.

I got my very first look at a bat up close: it was incredibly delicate, with caramel-colored fluffy fur, comically giant ears, and a face a bit like that of a very tiny dog. The bat looked at me with woeful skepticism, then slowly swung one wing across its face, tucking it away from the light just as one of us might shield our face with our arm. I fell in love on the spot. I’ve been helping with bat research ever since, whenever I have the opportunity, including a recent autumn night here in Redwood National and State Parks.

Bats comprise nearly one-fifth of all known mammal species—over 1,200 species worldwide. Despite being so common, bats are among the least understood or appreciated of all animals.  They are arguably one of the most ecologically and economically important organisms in the world. They control insect pests, including those that attack corn and other vital crops, pollinate a wide variety of plants from bananas to agave, and disperse seeds to restore forests; yet they continue to suffer, as they have for centuries, from human ignorance, myths and fears.

Redwood park researchers have caught nine bat species in their nets within park boundaries, but they believe at least 12 species occur regularly here, comprising a significant proportion of vertebrate diversity of the parks. All bat species occurring in the Pacific Northwest are insectivorous (insect eaters.) The little brown bat, found here in the redwoods as well as throughout much of the United States, can eat up to 1,000 mosquitoes in an hour!

Camping or even just sitting on your patio on a summer evening would not be nearly so an enjoyable experience without this bat.

Biologists survey bats in the parks using mist nets set over streams to catch them as they come to drink, or sonar detectors to pick up bat echolocation calls, the high-frequency sounds they use to navigate, hunt and communicate.

Bats send out sound waves and listen for echoes bouncing off prey, kind of like an extremely sophisticated version of the children’s pool game “Marco Polo.”  Generally inaudible to human ears, the sound waves of bats are translated by sonar detectors into a series of clicks which become increasingly rapid, and then a buzzing blur, as the bats zero in on an insect.

Scientists recently discovered that bats have something called “superfast muscles,” which were previously believed to only be found in some songbirds and snakes. Superfast muscles in the throat enable the bat, while closing in on an insect, to emit more than 160 to 180 calls a second, a phenomenon called “terminal buzz.” Seriously!

Bats can also be identified by their flight patterns and time of activity.  As I stood on a gravel bar in the middle of Mill Creek at dusk on a warm September evening, watching the researchers set up their equipment, one of the most common bats in the park, the Yuma myotis, began to swoop acrobatically up and down the stream just above the waters’ surface, whirling by my legs, but never touching me.

In addition to their ability to echolocate, bats aren’t blind. Swirling, spinning, and diving with incredible grace, they are the Cirque du Soleil of the animal kingdom. If I were an ace fighter pilot or even a prima ballerina, I would study the flight of bats carefully, in slow motion, to learn from the masters.

There is something to which we should all pay vigilant attention: Bats are disappearing. As we bite into our banana or ear of corn and take our walks in mosquito-free neighborhoods, we should consider this carefully.  More than 1 million of the flying mammals in the eastern United States have been killed by white-nose syndrome, a fast-moving fungal disease first detected in New York in 2006 that has spread steadily westward since. It has the potential to be one of the worst wildlife crises in history.

Most bats are long-lived with low reproductive rates and are therefore especially vulnerable to disease and habitat changes.  For instance, some bats reside in the cavities of old-growth trees, yet less than 5 percent of the original old-growth coast redwood forests remain.  We don’t completely understand how this drastic reduction in habitat has impacted bat populations, since we have no base studies from the 1800s for comparison. We do know, however, that some bat populations in this area are vulnerable and declining.  If white-nose syndrome arrives, the results could be devastating, and not just for the bats.

Halloween is a great time to reconsider our attitudes about bats. Yes, I admit they can startle us. In pursuit of a moth drawn to a porch light, they sweep by our heads at blinding speed, like Jedis on a mission. But bats do not want to get tangled in your hair or drink your blood (the few species that do live well south of the United States and prefer livestock). The chance of contracting rabies (less than 1 percent of wild bats are rapid) or even being bitten is absurdly low.  (However, never touch or handle a bat or any wild animal.)  And, no worries — Dracula lives in Hollywood, 723 miles south of here.

As you carve your pumpkin, install Styrofoam headstones in the yard, string up a long row of purple glowing bat lights (yes, I have some!), and listen for the laughter of tiny witches, pirates, and bed-sheeted ghosts scampering wildly through the neighborhood in the cloak of night, I hope you spot a bat or two dancing under the streetlights. These beautiful warriors of darkness have been around for at least 50 million years — way longer than we can even consider — and are far more deserving of our appreciation than our fear.

Your national and state parks have been set aside in part to provide safe habitats for these, as well as many other plants and animals. Bats are a very important and necessary component in the balance of this ecosystem. So, on this Halloween, blow a kiss to those that we may never fully understand, and resolve to fight for their future. And, ours.

• LEARN ABOUT BATS SATURDAY NIGHT
The Redwood Parks Association is sponsoring the 2011 Bat Walk at the Mill Creek Campground (event poster at right). A campfire program will begin at 6:30 p.m. at the amphitheater, and will be followed by a 30-minute night walk (participants should bring flashlights). Hot cider will be provided, but you should bring your own mug.