Biology Reference
In-Depth Information
leaves it hanging in the roost. After about a month, the bat pup is able to take flight and forage for itself.
Incidentally, one of the great mysteries of bat biology is how a mother can locate her pup among mil-
lions of bats in some of the largest bat caves.
Although bats have a low reproductive rate, they make up for it by a long life span; some bats have
actually been known to live twenty to thirty years, a remarkably long life for such a small mammal.
Many North American bats migrate with the onset of winter weather. Some travel only relatively
short distances to a cave, abandoned mine, or other suitable place to spend the winter where a fairly
even temperature is maintained. Others may migrate several hundred miles to find winter quarters. Al-
though hibernating bats need a temperature without wide fluctuations, they possess yet another unique
feature to protect them during their winter rest: some hibernating bat species can actually survive with
a body temperature as low as 23 degrees Fahrenheit.
There are about a thousand species of bats worldwide—about 25 percent of all known mammal spe-
cies. Of these, forty-three species are native to North America. Sadly, about half of these are in severe
decline, regarded either as threatened or endangered. Most of this decline is attributable to human activ-
ity. Partly it's due to carelessness or misunderstanding; such things as pesticide use, habitat destruction,
development, and human disturbance—particularly during hibernation—have all taken their toll. Dis-
turbance is especially destructive; simply agitating hibernating bats by entering their winter quarters
may cause them to burn up as much as sixty-seven days' worth of energy reserves.
Even worse has been the vandalism and wanton destruction of bats and their habitat. Some people
have even gone so far as to dynamite caves and abandoned mines where bats roost or hibernate, and
a variety of other methods have been used to harass and kill these harmless and beneficial creatures.
The bright side of this is that education is having an effect, and more and more people are coming to
appreciate how useful and amazing bats truly are. This gives us at least some hope that the decline of
our North American bats can be halted and perhaps even reversed—a goal we should all strive for.
