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AFGHAN ARABIA WILD
WILDLIFE OF AFGHANISTAN WILDLIFE OF SAUDI ARABIA NORTHWEST WILDLIFE ONLINE
Ask yourself this – how many times
have you actually seen a bat?
Most people would have to answer not many.
There’s an obvious reason for this, of course.
Bats are relatively small, dark colored, and tend to nighttime
activities. Small wonder we
miss them so easily. Behind
this obscurity, however, lurks a surprising fact:
there are more bats on earth than any other species of mammal except
one. Nearly one thousand
different species of them share this world with us.
Only rodents boast of greater numbers.
Bats belong to the order called Chiroptera, a derivative
of the Greek term “hand wing.”
A very apropos name for these astonishing creatures whose most obvious
physiological feature is its hand wing.
Thanks to this unique appendage bats are the only mammals capable of
flying due to their own muscle power.
Other mammals like flying squirrels and some lemurs can glide but
only bats actually flap their wings and create long distance flight - and
bats are the only mammal to have ever developed the ability.
To date no fossil evidence has been found that indicates mammalian flight
has ever existed before the appearance of bats. Bats also lay claim
to having the smallest member of the mammal family – the recently discovered
Kitti’s Hog Nosed bat of Thailand.
Sometimes called the Bumble Bee bat this little fellow was first
described in 1974. It is a
little more than one inch long and weighs in at less than an ounce.
There are moths bigger than that!
This as opposed to the almost six foot wing span of the Flying Fox
family of bats.
Bats other distinctive talent is echolocation. Well, of course, everyone knows that. True. But did you know that was not discovered until sometime in the 1930s and not really understood until the 1970s? Although not uncommon in the wild world, echolocation is one of those things that seems very straightforward at first. The animal emits a sound. That sound bounces off an object and returns to the ear of the emitter. From that the animal is able to determine the size and location of objects around it. Yes, that is the principle of the thing. But when several factors are considered the subject gets a bit more complicated. The frequency of a sound that echo locates insects, for example, has to be far more precise than that required to determine the boundaries of a cave. And how are shape and size deduced from sound alone? A bat hunting insects must be able to produce a high frequency sound, and detect the resulting echo, from amidst the hundreds or even thousands of its companions. Now that takes a special talent.
As previously noted the echo locating abilities of bats are directly related to its preference for food. Although nearly all species of bats have echolocation ability (there is one genus, Rousetta, in which it is lacking (Kunz and Pierson, 1994)) it is most critical for those species that hunt on the wing. Walkers’ Mammals of the World, 6th Edition lists several basic types of bats:
·
Insectivorous – the majority of species, they obtain insects for food
while in flight
·
Fruit
Eating – these are the largest species, the “flying foxes”
·
Flower
Eating – as the name implies these bats eat pollen and nectar, and as
such are tremendous pollinators
·
True
Vampire – despite their notoriety just three species of vampire bats
exist
· Carnivorous – prey on other small mammals, frogs, etc.
·
Fish
Eating – as the name implies these bats catch and eat fish
A bat that must snag a moth out of
mid-air while in flight is obviously much more dependent on echolocation
than a fruit eating bat. And
here is where frequency comes into play.
High energy, high frequency sound is key to pinpointing an animal as
small as an insect. Lower sound
waves suffice quite nicely for fruit or flowers.
Bats produce these sounds through their mouth or nose.
The returning echo is, of course, received in their ears, sometimes
aided by a special organ inside the ear called a tragus.
And this is what has given rise to the variety and downright bizarre
appearance of many Chiropterans.
A fruit eating bat such as the large flying fox, has a dog like face
that actually qualifies as endearing.
Compare this to the incredibly strange features of the leaf eared or
fish eating bats. No other
mammal on earth can lay claim to that degree of weirdness.
Bats are not blind, by the way.
Most have eyesight every bit as good as other mammals.
The myth of blindness is understandable, however, considering the
Chiropteran affinity for nocturnal activities and dark places.
And they are not all black or brown, either.
There are actually a couple of species of
white bats, some are even
tri-colored or white spotted.
Despite a body size comparable to small rodents bats have a relatively long
life, up to 30 years, with reports of 40 years.
But where rodents make up for their shorter life span by having
numerous young, bats generally raise just one “pup” per year.
Twins are occasionally born.
Bats have a world wide range, but do not live in
altitudes above tree growth according to Walker.
Cold climates in general are well inhabited by them as are just about
all tropical regions. Some
hibernate throughout winter or become torpid in colder weather, greatly
reducing their heart rates. But
abundant water does not seem to be a determining factor.
The author of this article has personally seen hundreds of bats
flying around some of the driest parts of southern Afghanistan.
Attracted by the moths and insects that hover around spotlights it is
possible that these animals have travelled some distance, too, since there
was no visible hiding places within sight.
The United States is home to about 45 species.
Many range into Canada and as far north as Alaska.
According to the Peterson’s Guide (see references below) about five
species of leaf nosed bats have a range that extends from tropical regions
into southern Texas. These
chiropterans feed on fruit, flower nectar – and yes – blood.
But don’t expect to see vampire bats if you visit the Rio Gran.
The vast majority of our species are
insect eaters beneficial to farmers and by extension all of us who depend on
farm products.
And about this business about bats and rabies.
Yes bats do occasionally carry rabies.
But you are much more likely to be bitten by some other rabid animal
that a bat. All mammals are
capable of carrying the rabies virus.
(In fact, only mammals
carry it.) Raccoons are the
most common carriers of the disease, but any animal acting strangely should
be avoided.
Bats are utterly incredible animals.
Prove it to yourself. Do
some research in your local library or on the internet and see if you can
find any other species of warm blooded creature that matches the order
Chiroptera in variety, behavior, or appearance.
Bet you can’t.
Bats of the
Northwest (Peterson’s Field Guide):
·
California
Myotis
Myotis californicus
·
Western Small
Footed Myotis
Myotis
Ciliolabrum
·
Yuma Myotis
Myotis yumanensis
·
Little Brown Myotis
Myotis lucifugus
(throughout US and Canada into Alaska)
·
Long-Legged
Myotis
Mytois
volans
·
Long-Eared
Myotis
Myotis evotis
·
Keen’s Myotis
Myotis keeni
·
Fringed Myotis
Miotis thysanodes
·
Western Pipistrelle
Pipistrellus hesperus
(throughout US and Canada into Alaska)
·
Silver-Haired Bat
Lasionycteris noctivgans
·
Big Brown Bat
Eptesicus fuscus
(throughout North America)
·
Hoary Bat
Laisurus cinereus
(throughout North America)
·
Spotted Bat
Euderma maculatum
·
Townsends Big Eared Bat
Corynorhinus townsendi
·
Pallid Bat
Antrozous pallidus
NOTE: This word “Myotis” that pops up so often in relation to bats is, according to the online Oxford Dictionaries, a modern Latin term derived from the Greed word mus, mus-mouse. Apparently the intent of the word is to convey a description of “mouse like.”
REFERENCES:
Walker’s Mammals of the World,
volume 1, 6th Edition
Peterson’s Field
Guide – Mammals of North America, 2006 Edition
Online
References:
Bat Conservation International:
Bat Facts:
http://www.batworlds.com/bat-echolocation.html
Encyclopedia.Com
http://www.encyclopedia.com/topic/Echolocation_(Physiology).aspx
ZooBorns:
http://www.nwcn.com/home/?fId=228859311&fPath=/news/local&fDomain=10212
Bat Rescue:
http://www.batrescue.org/batfacts/batfacts.html
AFGHAN ARABIA WILD
WILDLIFE OF AFGHANISTAN WILDLIFE OF SAUDI ARABIA NORTHWEST WILDLIFE ONLINE