Thursday, April 28, 2011

Silver-Haired Bat

Today when I arrived at work Dr. C from the University was in my office and asked me if I would like to see a silver-haired bat hanging onto the side of a tree? "Of course!" Did he even have to ask? We grabbed Dr. Ashley and headed out into the timber to see the bat. It was clinging to the side of a tree about 4 feet off the ground. This is the first time I've ever seen this particular species. 

Silver-haired bats (
Lasionycteris noctivagans), which also go by the name of Silverwings are medium sized bats covered in dense black hairs . The hairs on their back are tipped in silvery gray. 


The species name of this bat translates into "night wandering shaggy bat."


Their preferred habitat is forested areas, which is exactly where we found this bat. There is a patch of timber directly behind our office building that the University uses for their ecology class, biology class and herpetology classes. I use the trail through the timber for trail hikes with visiting school groups. 

Silver-haired bats hide out during the day in cavities within trees, and under the bark of trees. Why this particular bat was clinging to the side of the tree completely exposed to the elements and prying eyes is a mystery, especially since there are shagbark hickory trees within 10 feet of where this bat was located.

Shagbark hickory's are one of the most common trees in the timber near our office. I like to point them out to the children, and talk about how special they are.They have such "shaggy" bark and grow incredibly tall. I always ask the kids if they like the cartoon Scooby Doo? They all raise their hands. Then I ask them who Scooby's best friend is....they all answer "Shaggy". Then I ask them to look in the woods around them and find the "shaggy tree" It takes them a few minutes, but they all find it. I confirm that they are right, then tell them the tree is called a Shagbark Hickory. 
Then I tell them to hold up their fists, and explain to them that an animal the size of their fist lives under the bark of the shagbark hickory tree during the day and comes out at night to hunt insects. Do they know what it could be? I get many responses from Birds, bugs to snakes, but eventually they settle on bats, and of course they are right. 

Had the silver-haired bat chosen to rest under the bark of the Shagbark it would have been a better choice, but for some reason it seemed content right where it was. We were able to get close to it and photograph it, and at no time did it seem alarmed or bothered. Our voices didn't even bother it. Hopefully it wasn't sick, although Dr. Ashley didn't seem to think it was.

This bat is found throughout the United States with exception to Florida. Their northern most range is Alaska and parts of Canada. They even range into Mexico. They feed on a wide variety of insects including moths, caddisflies, mosquitoes, crickets and beetles. 

These bats form maternity colonies in tree cavities or small hollows. Mating takes place in early fall and fertilization is delayed until the following spring. Two pups are born between late June and early July. Just before birth takes place the female will begin to roost with her head facing upward. She will hold her tail membrane forward to form a cup-shaped basket which will catch the pups as they are born.


Adults may live up to 12 years, providing they aren't preyed upon by skunks, feral cats, owls or raccoons. Silver-haired bats are one of the slowest flying bats in the animal kingdom, which could account for their susceptibility to predation. Unlike other bats this species roosts singly instead of with other members of their kind. 

This species is somewhat migratory. In its northern most range it will migrate south and spend the winter in caves or other secluded locations. Little else is known about their hibernation habits. These bats are one of the most common bats found in the United States. They are known to carry a special strain of rabies that is reported to be only in this species and the Eastern Pipistrelle . 

Reported deaths have occurred due to this strain of rabies. Silver-haired bats have very tiny, sharp teeth capable of biting without undue pain. Many people are bitten and do not even release they've been bitten. The puncture wounds are so tiny as to be almost unseen. These particular cases of rabies have been primarily reported from the more northern and northwestern regions of their range. It is always best to not handle a bat, this is especially true of a bat found during the daylight hours. Better safe than sorry. That being said, bats are one of the most important predators of insects in the animal world. The presence of rabies in bats is relatively low, with approximately 1/2 of one percent of bat populations carrying the virus. The good outweighs the bad and bats should be tolerated. I have put up bat houses hoping to attract them to our farm, but so far they have not used them. Hopefully one day they will take up residence here.


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