These bats favor roosting in both dense deciduous and coniferous forest areas and are the most common forest bat.  They prefer to be near water, in tree cavities, bark crevices and wood piles during the day.  The Silver Haired Bat prefers Old Growth forests, which with the Logging Industry are becoming more and more scarce.  They also have been found in sheds, cave openings and mines, in the Northern regions during hibernation months as well.  They are solitary roosters and are rarely found in groups (save for Maternity Colonies).  Silver Haired Bats are found roosting ten times more in Old Growth Forests than other sites.  It would also seem they adjust their flight patterns around other bat species, such as the Brown Bat, so as to not coincide flight times.  They most often take to the air in early evening, before sunset, and right before sunrise, for feeding.  They are a migratory species and fly down to Southern regions between August and October for the winter and colder months.  They are known to hibernate in cave and mine entrances in the lower regions.

 

Silver Haired Bats are insectivorous and prefer soft bodied insects, such as moths and flies.  They like to hunt within insects which fly in swarm groups.  But, they have also been known to forage at both ground level and tree level and have also have been observed eating spiders and larvae from tree trunks and bark.  They are also low level hunters with their preferred hunting grounds being over undisturbed areas of bodies of waters, small clearings, roadways and forest edges.  They hunt using their sharp teeth and also have the ability to use their tail membrane as a type of catching mitt to capture their prey while in flight.  They are one of the slowest bat species, yet very maneuverable.  They fly at up to speeds of 4.8-5 meters per second.  This species locates their food by echolocation.

 

These bats are believed to mate, while in flight, during the autumn months, prior to migration.  Fertilization does not occur, though, until spring.  Females store the males sperm while in hibernation and once fertilization occurs, at the beginning of spring, gestation is 50-60 days.  During this time the females will congregate in Maternity Colonies in April and May.  These Maternity Colonies tend to congregate in tree cavities and small hollows 13-39 feet up, with the male bats roosting several feet below the colonies.  The roosts tend to be on the south side of the trees.  Roosts are relocated often between trees by both sexes.  

 

Birthing yields 1-2 offspring in the months of April and May.  Females give birth to their pups breach style and are able to form their tail membrane into a sort of basket, catching the pups after birth.  Babies are born hairless and pink.  Each baby can be up to 2 grams, 36 percent of the mother’s weight.  During this time it would appear that the sexes segregate during the weaning period of the pups, which takes approximately 5-6 weeks.  Within 21-36 days pups are able to feed themselves. Communication between this species is done by echolocation and sound.

 

This species is not considered endangered or protected.  There is an ever growing concern for their living environment due to the Logging Industry and Forest Conservation.  There is a call for conservation of forest corridors and maintenance of Old Growth areas for this species who is very particular about their roosting sites.  The White Nose Syndrome, a fungal disease that affected several bat species in the United States, does not seem to have greatly affected the Silver Haired Bat numbers.  

 

While this bat is valuable to our ecosystem for insect control, it does carry rabies and is blamed for the majority of rabies related deaths in humans recently.  Since 1981 there have been 25 cases of rabies related human deaths.  Of these cases 16 have been attributed to the strain of rabies, called the "Ln" strain that the Silver Haired Bat carries.  While the victims rarely recall actually come into contact with a bat, there have been cases of bite marks being found on the victims.  Research shows that the strain that the Silvered Haired Bat carries contains a higher level of infectivity due to genetic changes within the Ln strain.  In 2003 the Center for Disease Control (CDC) formally recognized the Silver Haired Bat as being the leading cause of Rabies in the United States. 

 

Bats Away is your NJ bat removal expert for all of your bat problems.