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Bat Country

Updated: Aug 10, 2020

Few pleasures can match a quiet drive at dusk along a lonely gravel road in Iowa during midsummer. The fireflies twinkle like earthbound stars, cicadas drone, toads trill, and the silky pastels of sunset slowly give way to a night sky bereft of the streetlights and parking lots that ruin the view in town.

All the better when we have a good excuse to get out, and tonight, we do. We’re doing a “bat survey,” which includes mounting a microphone and GPS unit on the top of the truck, attaching them to a device called an Anabat, and cruising at 20 miles per hour from St. Sebald Church near Strawberry Point all the way to Edgewood.

Anabat (left) and microphone

It’s a pretty nifty system. The microphone picks up bats’ ultrasonic echolocation calls, converts them to a digital signal, and records them on an SD card. Specialized software then converts that information into a visual format on a computer, where researchers can look and see what kinds of calls the device recorded.

Readout of bat calls recorded by Anabat
Readout of bat calls recorded by Anabat

Each bat’s echolocation calls has a distinct signature, enabling researchers to identify the species and location of bats along the survey route. The survey is part of a multi-year project by the Iowa DNR and Iowa State University to develop a better sense of bat populations throughout Iowa.

Clayton County's piece of the pie

Timely work, to be sure. Bat populations have absolutely plummeted in the last decade or so thanks to the arrival of White Nose Syndrome. The syndrome develops from a fungus that irritates the bats, and causes them to wake from their hibernation in the middle of winter.

When the irritation causes them to fly from their hibernaculum (often a cave, sometimes a building) during a time of year with no insects, the bats quickly starve. When White Nose strikes a colony, it wipes out anywhere from 70-90% of the bats, sometimes even more.

I had the misfortune of witnessing this drama firsthand when I helped out with a winter bat count at Spook Cave near McGregor. Historically, the cave had provided a peaceful hibernating spot for literally hundreds if not thousands of bats each winter. The day we went in, we found two.

Heading in to count bats

The ecological value of bats cannot be overstated. The center for biological diversity estimates that bats provide anywhere from $3.7 billion to $53 billion in non-toxic pest control services. They do their work mostly unnoticed by humans, unless they take up residence in an undesirable location.

For that reason, we often fail to appreciate their abundance and diversity. But a driving transect with a bat monitor quickly changes one’s perspective. The device chirps and squeaks whenever the microphone picks up a bat.

As we meander along lonely backroads, the anabat tells us they’re everywhere. It comes alive at virtually every farmstead and creek crossing. I’m heartened by the considerable activity; the last few years have seemed alarmingly quiet, but perhaps the tide has started to turn.

Bats, like pollinators, have seen a dramatic shift in their reputation amongst the general public since their numbers began declining. They have finally begun to get the attention they deserve, and what used to be a “nuisance” animal is now a welcome sight at dusk – even if that sight is a little less common.

Bat boxes have become a more common sight in backyards and park lands across America as humans seek to provide for an animal that has given so much to us. While they have a long way to go to become as commonplace as bird feeders, it’s a start.

Bat box with no vacancy

Maybe the night of this transect just happened to be a fruitful one. Maybe I’m just imagining a rebounding population. But I’m happy to be out there, and I’m happy that science has helped us find a way to recognize and count an animal whose family makes up roughly ¼ of all the mammal species on earth.

If you want to be a part of the solution, all you have to do is remember the three things every animal needs: food, water, and shelter.

Making your property bat-friendly actually can help those aforementioned pollinators, since the former eats the latter. Moths make up a major portion of most Iowa bats’ diet, and moths need nectar. A good pollinator garden, then, can make for a spectacular sight during both the day and the night. Fragrant flowers and night-blooming plants can add an extra layer of appeal for bats.

Hummingbird moth visits a blazing star flower

For shelter, bat box plans abound with simple construction and placement ideas. If you have a woodland by your property, you can help bats find a place to rest by leaving a few dead or dying trees, as many bats roost in tree cavities or under peeling bark.

Shagbark Hickory provides great roosting habitat

While bats have remarkable agility on the wing, they struggle to forage through heavy brush. Invasive plants like Multiflora Rose and Honeysuckle that have taken over many woodlands make for poor bat habitat. Any efforts to restore native understory help timber production, pollinators, and bats all at once.

Sometimes nothing beats scrap wood in an old shed...

Looking Back

This July marks one of the busiest in memory at the Osborne Nature Center, as well as our other Clayton County Conservation Board properties. On top of a near-constant bustle of activity from visitors enjoying their public lands, we had more than a few great programs and developments to get people outside.

On July 14th, the CCCB partnered with ISU Extension & Outreach to host a survival camp at Osborne. Participants made mini survival shelters, talked edible plants, and left a little more prepared for the great outdoors.

Not the sturdiest shelter, but he looks happy nonetheless

On July 18th, The Ghosts of Motor program brought history to life with stories about the old mill and the town of motor.

On July 30th, the 3rd annual Motor Mill STEAM camp brought students together to learn a little science, technology, engineering, art, and mathematics. They couldn’t have asked for a more beautiful day!

On the development front, the Osborne Disc Golf Course added a back 9 through the timber north of the Osborne Pond! The course is primitive – no tee pads - but the back 9 is a great spot for beginners and experts alike to develop their technical skills.

Teeing off #14 at Osborne

At Motor Mill, over a century of accumulated sediment has been removed from the basement thanks to the work of John Moyna and CJ Moyna & Sons Construction, and a little bit of elbow grease from County Conservation staff. The excavation unearthed three of the four original turbines used to ground flour at the mill. Neato!

Mill basement mid-excavation. Silt had piled to the beams above.

On the habitat front, thanks to a generous grant from the Iowa DNR, the Becker East and West wildlife areas have seen a concerted attack on the Multiflora rose infestation. Not only will the continued eradication of this thorny plant help hunters navigate the site, it should make the bats happy as well!

Where once were thorns...
...Now is shorn! Wow that was bad.

Last but not least, firebreaks were mowed at Osborne and the Motor Mill Historic Site. Why mention that here? Because the prairies are spectacular this time of year, my friends, and if you don’t like wading through chest-high grasses this is the time of year to get out and see them! Mowings wait until bird nesting season has wound down.

Between the archery ranges at Osborne Park

Looking Forward

Next month, weather permitting, will be the second to last Pedal, Paddle, Purchase bike and canoe trip on August 8th from Elkader to Frieden Park, and back down to Elkader by way of the Turkey River.

We’ll also see off our interns for the season and be back to the core group for the year. Time flies, and before long it’ll be time to start planning for the fall – no easy task this year to be sure, but we will keep you tuned.

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