Little Brown Bat To quote from "Alice in Wonderland" - "Twinkle, twinkle little bat. How I wonder where you're at. Up above the world so high, like a tea tray in the sky. Twinkle, twinkle little bat, how I wonder where you're at."

I've been worried about our little furry, flying "mice." I had seen a few flying around in the spring on Mackinac Island but until recently, I hadn't been aware of many out and about. The middle of July is usually the time they appear in abundance, and locals had been looking for them to help with the overabundance of mosquitoes that we've experienced this year, owing to all the rain we've had. Another reason I was concerned is because of the decline in bat population, which has been occurring in eastern North America. Anyway, I was delighted yesterday, when stopping in at the city hall, a young boy came running into the stairwell yelling, "There are four bats, no five, no six bats!" in Mackinac Island's Community Hall.

It turned out that there were seven bats altogether. A friend of mine commented at the time that she had been in a restaurant the other evening, when some visitors were complaining because a bat flew in. My friend explained to them that she was happy to finally see them flying about.

By the way, in China, bats are a symbol of happiness, and are often woven into or embroidered onto fabric or painted onto porcelain. Frankly, I rather like these mammals, although not in my house.

Bats are the only true flying mammals. Worldwide, there are more than 950 species of bats, and they make up more than one quarter of the species of mammals. On Mackinac Island, bats are the most common mammal.

The most frequently seen bat at Mackinac is the little brown bat or little brown myotis (Myotis lucifugus). This small bat is only three to four inches long and weighs in at only 0.2 to 0.4 ounces. The coat of this bat is olive brown to dark yellowish brown on the back and a bit paler underneath. It also has black ears. These bats occur across most of North America, and live as far north as any bat species. In the winter, they hibernate in caverns and abandoned mines, where the air temperature is between 36 and 40 degrees Fahrenheit, and the humidity is between 80% and 100%. These bats can go into true hibernation because they have the ability to raise and lower their body temperature. By lowering the body temperature, they can lower their metabolism, reducing their need for energy and food, and therefore they can go into hibernation. Some mines have been found to house more than 300,000 little brown bats, though most have fewer. This bat will form loose clusters with other bats during hibernation, unlike many of the other northern bats. They usually leave their caves in April, and will fly up to 210 miles to their summer homes.

After winter hibernation, the male little brown bats are found solitary roosting in hollow trees (I found one in a hole made by a pileated woodpecker), and behind shutters and awnings.

Females, on the other hand, form maternal colonies that are often found in barns, houses, churches ("bats in the belfry"), and can consist of up to 300 or more adults. This species of bat can tolerate much warmer temperatures (up to 100 degrees Fahrenheit) than some of the other northern species, which is why they're often found in attics around here.

These bats forage for food anytime during the night, but are most active during the two or three hours after sunset, and eat a variety of insects. Their favorites are the larval stages of aquatic insects. Therefore, they're often found foraging over ponds, lakes, and streams. A little brown eats thousands of insects each night, and a lactating female can eat more than her own weight in one evening.

Little brown bats mate in late summer, but the female stores the sperm until April, after she has woken from her winter nap. The gestation period is about 60 days, but may vary. If the temperatures are cold, and it's rainy, and few insects are flying, the females may go into torpor, which lessens the demand for energy but also slows fetal growth. This may explain the slightly late appearance of bats this summer. With the cold and rainy spring that we had, things may have slowed down. It takes about a month after the single pup is born before it can forage on its own. This is why it always seems that we have a lot of bats suddenly appearing in mid-July, when the young leave their moms and go out on their own.

This is also when I get hit with bats while biking around the Island in the evenings. I always figure it's like giving car keys to teenagers; young bats, like kids, haven't had a ton of practice, and may make some miscalculations in flight.

These bats live longer than most bat species; in fact, one book I read called them the Methuselahs of the bat world, as they live up to 33 years in the wild (males live longer than females). Birds like hawks, owls, gulls, and other predators may occasionally eat these mammals. Exterminators sometimes kill populations, instead of just sealing up entrances into attics when the bats are out. In addition, if bats haven't stored up enough fat to get them through a long winter, which is more common in the young, they will sometimes run out of fat stores in February or March, and starve to death during hibernation.

Now we're beginning to see massive die-offs of bats in caves in five East Coast states, and little browns are among the bats affected. No one knows exactly why these bats are dying, but many of them have a white fungus on their faces, giving it the name "whitenose syndrome." Thousands of bats are dying. Caves that once housed thousands of bats are now being found with only a few hundred.

Not only are scientists finding white fungus, but also odd behavior patterns. Clusters of hibernating

bats have been migrating oddly close to cave entrances, and starving bats have been seen leaving the cave during the winter. Some of the bats are dying of starvation during hibernation, their fat stores depleted. It is not known if the fungus is killing the bats, or if it is merely affecting bats whose immune system is already compromised by something else. Hibernation naturally lowers the body's immune response, and may make them more vulnerable to cold-resistant pathogens. The caves are usually between 36 and 40 degrees Fahrenheit in the winter. Most fungi don't grow well in these types of conditions, even though they like the high humidity of the caves. This white fungus may be able to survive and grow, despite the cold temperatures, or it could be some other environmental factor affecting the bats, perhaps an off-shoot of environmental development or farming.

It is interesting to note that all six species of bats that have been affected so far (Eastern Pipistrell, little brown, big brown, northern long-eared, small footed, and Indiana) are all nocturnal, insecteating bats that hibernate in caves during the winter and slowly burn body fat, staying only marginally warmer than the cave or mine. Several of the bats affected are of the species that live on Mackinac. While research is continuing, we have to hope that this "whitenosed syndrome" doesn't spread out of the Northeast and reach our furry little friends.

Keep an eye out for the bats. Thank them for eating insects, and remember, they represent happiness, so I hope they bring some to you.

Trish Martin is a year-around resident of Mackinac Island, has earned a master's degree in botany from Central Michigan University, and owns Bogan Lane Inn. She writes weekly for the Mackinac Island Town Crier.