Bat

Bats (order Chiroptera) are flying mammals with forelimbs developed as wings. While other mammals like flying squirrels[?] or gliding phalangers[?] can only glide limited distances, the bats are the only mammals truly able to fly.

Anatomy

The metacarpal bone and the second and fifth toe of the forelimbs are elongated, and between these toes is a membrane, called "chiropatagium". The membrane extends from the toes to the body side and from there to the base of the hindlimbs. The entire wing of a bat is called "patagium". Many species also have a membrane between the hindlimbs enclosing the tails. This membrane is the "uropatagium".

The patagium is full of fine blood vessels, muscle fibres and nerves. When it's cold, the bats wrap themselves up in their wings like in a coat. In warm weather they stir the wings in order to cool their bodies.

The thumb and sometimes the second toe of the forelimbs wear claws, as do all five toes of the hindlimbs. The rear claws enable the bat to hang itself on to a tree branch, a ledge or something else. Bats are also able to move on the ground, but it appears rather clumsy. Even if a bat falls into the water, it can manage to reach the shore.

All bats are active at night or at twilight, so the eyes of most species are poorly developed. (There are some exceptions with rather large eyes.) Instead the nose and the ears are excellent. The microbats use an echolocation organ to orientate themselves.

The teeth resemble those of the insectivores. They are very sharp in order to bite through the chitin armour of insects or the skin of fruits.

Reproduction

A newborn bat clings to the fur of the mother and is transported several days. It would be difficult for an adult bat to carry more than one young, so normally only one young is born. Two mammary glands[?] are situated between the chest and the shoulders. Only the mother cares for the youngs, and there is no continuous partnership.

The ability to fly is congenital, but after birth the wings are too small to fly. Young microbats become independent at the age of 6 to 8 weeks, megabats not until they are four months old. At the age of two years bats are sexually mature.

Enemies

Small bats are sometimes preyed by owls and falcons. Generally there are few animals able to hunt a bat. In Asia there is a bird, the bat hawk[?], specialized in hunting bats.

The worst enemies are parasites. The membranes with all their blood vessels are ideal food sources for fleas, ticks and mites. Some groups of insects suck exclusively bat blood, e.g. the bat flies[?]. In their caves the bats are hanging close together, so it is easy for the parasites to change the host.

Classification

There are two suborders of bats:

1. Megachiroptera (megabats or fruit bats)
2. Microchiroptera (microbats, echolocating bats or insectivorous bats)

Megabats eat fruit, while microbats eat mainly insects, and often rely on echolocation for navigation and finding prey.

Once it was believed, that megabats and microbats developed independently. The shared characteristics would be a result of convergent evolution. After numerous genetic analyses it seems clear, that both groups have a common ancestor and are therefore related to each other.

Little is known about the evolution of bats since their small, delicate skeletons do not fossilize well. The oldest known bat fossiles are Icaronycteris, Archaeonycteris, Palaeochiropteryx and Hassianycteris from the early Eocene (about 50 million years ago), but they are already very similar to modern microbats.

Bats are usually grouped with the tree shrews (Scandentia), colugos (Dermoptera), and the primates in superorder Archonta[?].

Diseases

Of the very few cases of rabies reported in the United States every year, most are caused by bat bites. Although most bats do not of course have rabies, an infected bat may be disturbed, clumsy, disoriented, and unable to fly, which make it more likely that it will come into contact with humans. Although one should not have an unreasoning fear of bats, one should avoid handling them or having them in one's living space, as with any wild animal. If a bat found in living quarters near a child, mentally handicapped person, intoxicated person, sleeping person, or pet, the person or pet should receive immediate medical attention for rabies. Bats have very small teeth and can bite a sleeping person without necessarily being felt.

If a bat is found in a house and the possibility of exposure cannot be ruled out, the bat should be sequestered and an animal control officer called immediately, so that the bat can be analyzed. This also goes if the bat is found dead. If it is certain that nobody has been exposed to the bat, it should be removed from the house. The best way to do this is to close all the doors and windows to the room except one to the outside. The bat should soon leave.

Due to the risk of rabies and also due to health problems related to their guano, bats should be excluded from inhabited parts of houses. For full detailed information on all aspects of bat management, including how to capture a bat, what to do in case of exposure, and how to bat-proof a house humanely, see the Centers for Disease Control's website on bats and rabies (http://www.cdc.gov/ncidod/dvrd/rabies/Bats_&_Rabies/bats&.htm).

Cultural aspects The bat is sacred in Tonga, West Africa, England, Australia and Bosnia, and is often considered the physical manifestation of a separable soul[?]. Bats are closely associated with vampires, who are said to be able to shapeshift into bats, fog or wolves. Bats are also a symbol of ghosts, death and disease. Among some Native Americans, such as the Creek, Cherokee and Apache, the bat is a trickster spirit. Chinese lore claims the bat is a symbol of longevity and happiness, and is similarly lucky in Poland and Macedonia and among the Kwakiutl and Arabs.

External links

• http://animaldiversity.ummz.umich.edu/chordata/mammalia/chiroptera
• http://tolweb.org/tree?group=Chiroptera&contgroup=Eutheria
• http://katydid.uni-graz.at/batkey/

• In Egyptian mythology, Bat is an alternate spelling for Bata, which see for more details.
• baseball bat[?]
• cricket bat[?]