Batty Aurora

Foraging bats during aurora

This morning's geomagnetic storm was just a dull green arc until about 2 a.m., then colors and shimmering ramped up for about an hour. Meanwhile, I was entranced by the sound of wing beats from 10-20 bats foraging over the water close to me. These images are a combination of several frames of long exposures for the aurora with a flash pop for the bats at the beginning of each exposure. A calm night at Island Lake in northwestern Montana.

Going Batty in Glacier

Left to right: Silver-haired bat, Long-eared Myotis, Little Brown Myotis

Triple mist net set over the inside North Fork Road at 1AM

Got to tag along with the park biologists last night / early this morning to catch bats around Ford Creek, near the northwestern corner of Glacier Park. My friends lured me in with rumors of "huge" moths getting tangled in their bat nets.

We ran a series of five nets in four locations, including two over-water sets and one triple-tall net on a pulley system that they set over the inside North Fork Road. Fortunately, there isn't a lot of traffic between 10PM and 1AM in that part of the middle of nowhere.

We caught a total of 16 bats, if my foggy memory holds up, including a pregnant Long-eared Myotis, several Silver-haired Bats including one with what appeared to be tiny orange mites behind his right ear (ooohs and aahhs from all of us biologist types), and a couple of Little Brown Myotis which is probably our most common bat in western Montana.

We got to see many of our most amazing native animals up close and personal, and collect measurements and other valuable data on these little-known species, so the sleep deprivation was definitely worthwhile. But I didn't see a single large moth, much less a "huge" one. I think I got snookered.

Quiet Company

Our end-of-summer company last week included a polite and quiet, Little Brown Bat (Myotis lucifugus). She slept on our sunny west wall, just outside the opening to a warm and skinny bat roost that's used all summer. I don't know why this one was outside, in the light, but maybe it had something to do with migration. She left at dusk.

A visiting Little Brown Myotis bat, asleep on our wall

Little Brown Bats are one of the most common bats in N. America, ranging across most of Canada and the northern U.S.  Beyond that, we don't know much about the bats living in Montana. There are scattered reports of bats wintering in abandoned mine shafts, but there don't seem to be any large "hibernacula" sites in our state. Based on a handful of observations, we suspect that most of our Little Brown Bats winter locally, within 100 miles or so of their summer home, so maybe this one was just passing through for one night.

Two weeks ago, on the other side of the mountains, a bat research crew in Glacier Nat. Park enjoyed their best night of the whole summer - what is now referred to as, "The Night of the Hoaries." In the wee hours of 13 August, the crew captured 38 Hoary Bats (Lasiurus cinereus) while mist netting in the Belly River Drainage, near the park's northeastern corner. That number was almost triple their previous best for Hoaries. Everyone agreed, it was a great way to end fieldwork for a grueling, two-year study.

Hoaries are one of the largest and prettiest bats in N. America, with silver-tipped fur that the common name pays homage to. They range across the eastern two-thirds of Canada and all of the U.S. and Mexico. But unlike the Little Browns, Hoaries don't use human structures and are therefore seldom seen. They spend winter near the Equator and are solitary year-round, except during migration.

Those 38 Hoary Bats caught by the exhausted research crew were migrating south out of Canada, passing through Montana on their way to the tropics. During migration groups of Hoary Bats travel in "waves," often flying with migrating birds at night. Unfortunately, this behavior brought them trouble with the new turbines sprouting up in windy areas.

A few years ago, just across the border in Canada, biologists from the University of Calgary set out to study bat fatalities at these wind farms. Mitigation efforts had reduced bird deaths from the turbines, leaving bats as the most frequently killed animal. They found that the sudden drop in air pressure near the blades was injuring the bats' lungs, what's called "barotrauma."

But the researchers also found that, by increasing the minimum wind speed at which the blades begin to turn, and slightly changing the blade angle, they could reduce bat fatalities by 57% and 60%, respectively. That's because bats don't like to fly in high winds, and modifying the turbines reduced their speed when the bats were most active.

Little by little, year by year and location by location, we are slowly learning how to live with bats.


Full moon rising behind one of the hundreds of wind turbines spinning near Shelby, Montana

A Bat Emergency

One of the most dangerous disease spreaders is, of course, the mosquito. Which is just one more reason why I love bats. Bats are smart, shy and reclusive -- and they literally eat tons of mosquitos. Once you learn what bats are really all about, you'll love them as much as I do. Okay, maybe not. But at least you might gain some respect for these amazing animals.

The good news is, several dedicated groups are working hard to erode the mis-information and myths that surround bats:

VISION. Bats are not blind. In fact, they see quite well. And their echolocation is thousands of times more efficient than anything humans have been able to build.

RABIES. Bats do not "carry" rabies, and less than one-half of one percent of bats actually contract the disease. When infected they do not become aggressive, but tend to become listless and die rather quickly. (Little brown bats -- our most common species -- have never been documented transmitting any disease to a human.) More people die from domestic dog attacks every year than die from bat rabies in a decade. Statistically speaking, we would be hundreds of times safer if we got rid of bicycles instead of bats.

INSECTS. Our most common bat here in Montana, the little brown bat (Myotis lucifugus), lives near ponds and lakes, eating up to 1,200 mosquitoes per hour. Think about how that might impact West Nile Virus, which is carried by mosquitoes and is fatal to humans. The big brown bat (Eptesicus fuscus) eats night-flying insects that plague our crops. Just one example -- one big brown bat can eat enough cucumber beetles in one summer to eliminate 220,000 of the root worm larvae. Without bats, how much more expensive would your favorite foods be due to crop losses and increases in pesticide use?

POLLINATION. World-wide, bat pollinate and disperse the seeds of more than 450 food crop species and 80 medicinal plant species. More than 95% of rainforest regrowth comes from seeds dispersed by bats.

The bad news is, bats now face a new threat to their survival. White-nose Syndrome (WNS), is named for a white fungus that appears on the faces of infected bats. Since its discovery in a single New York cave in 2006, WNS has killed more than a million hibernating bats. The mosquito-eating, little brown bats appear to be the hardest hit. WNS is rapidly spreading south and west, and it's about 95% fatal. A number of bat species are at risk of going extinct within a matter of years, unless we can find a solution to the WNS emergency. To learn more about WNS and how you might help, read more at Bat Conservation International (link below).

If you'd like to hear some personal stories about bats, check out my blog entry on some of my batty experiences. That essay includes the story of the baby bat (called a "pup") shown at the top. She's about one week old, and she's probably a little brown bat. She apparently fell out of a nursery colony, or she was accidentally dropped in flight by her mother. Like the future of all bats, her fate is unknown.

Bat Links:

What to do if you find a bat
Bat Conservation International
Bats of Montana

Behind the lens: Bat pup photographed with a Panasonic Lumix DMC-FZ20 "point and shoot" on macro mode. My apologies for the distorted, leather-gloved fingers...