Bats
IdentificationBats are mammels in the order Chiroptera. The forelimbs of all bats are developed as wings, making them the only mammals naturally capable of sustained flight. The word Chiroptera comes from the Greek words cheir (χειρ) "hand" and pteron (πτερον) "wing," as the structure of the open wing is very similar to an outspread human hand with a membrane (patagium) between the fingers that also stretches between hand and body. |
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A measure of the success of bats is their estimated total of about 1,100 species worldwide, accounting for about 20% of all mammal species. About 70 percent of bats are insectivores. Most of the rest are frugivores, with a few species being carnivorous. Bats are present throughout most of the world. Bats perform a vital ecological role by pollinating flowers, and also serve an important role in seed dispersal. Many tropical plants are entirely dependent on bats.
Bats range in size from Kitti's Hog-nosed Bat measuring 29–33 mm (1.14–1.30 in) in length and 2 g (0.07 oz) in mass, to the Giant golden-crowned flying fox which has a wing span of 1.5 m (4 ft 11 in) and weighs 1.2 kg (3 lb).
By emitting high-pitched sounds and listening to the echoes, also known as sonar, microbats locate prey and other nearby objects. This is the process of echolocation, an ability they share with dolphins and whales. Two groups of moths exploit the bats' senses: tiger moths produce ultrasonic signals to warn the bats that the moths are chemically-protected (aposematism) (this was once thought to be the biological equivalent of "radar jamming", but this theory is still unconfirmed); the moths Noctuidae have a hearing organ called a tympanum which responds to an incoming bat signal by causing the moth's flight muscles to twitch erratically, sending the moth into random evasive manoeuvres.
Although the eyes of most microbat species are small and poorly developed, leading to poor visual acuity, it is incorrect to assume that they are nearly blind. Vision is used as an aid in navigation especially at long distances, beyond the range of echolocation. It has even been discovered that some species are able to detect ultraviolet light. Their senses of smell and hearing are excellent.
The teeth of microbats resemble those of the insectivorans. They are very sharp in order to bite through the hardened armor of insects or the skin of fruit.
Bats may have one to three litters in a season, depending on the species and on environmental conditions such as the availability of food and roost sites. Females generally have one offspring at a time. Female bats nurse their youngster until it has grown nearly to adult size; this is because a young bat cannot forage on its own until its wings have assumed adult dimensions. Female bats use a variety of strategies to control the timing of pregnancy and the birth of young, so as to make delivery coincide with maximum food ability and other ecological factors.
Young microbats become independent at the age of 6 to 8 weeks, megabats not until they are four months old.
A single bat can live over 20 years, but the bat population growth is limited by the slow birth rate.
Behavior
Most microbats are active at night or at twilight.
Many bats migrate, while others pass into torpor in cold weather but rouse themselves and feed when warm spells permit insect activity, and still others retreat to caves for winter and hibernate for six months. Bats rarely fly in rain- the rain interferes with their echo location, and they are unable to locate their food.
The social structure of bats varies, with some bats leading a solitary life and others living in caves colonized by more than a million bats.
Damage & Health Risks Bats are natural reservoirs or vectors for a large number of zoonotic pathogens including rabies, severe acute respiratory syndrome (SARS), Henipavirus (ie. Nipah virus and Hendra virus) and possibly ebola virus. Their high mobility, broad distribution, and social behaviour (communal roosting, fission-fusion social structure) make bats favourable hosts and vectors of disease. |
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Many species also appear to have a high tolerance for harbouring pathogens and often do not develop disease while infected.
Only 0.5% of bats carry rabies. However, of the few cases of rabies reported in the United States every year, most are caused by bat bites. Although most bats do not have rabies, those that do may be clumsy, disoriented, and unable to fly, which makes it more likely that they will come into contact with humans.
Although one should not have an unreasonable fear of bats, one should avoid handling them or having them in one's living space, as with any wild animal. If a bat is 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 being felt. There is evidence that it is possible for the bat rabies virus to infect victims purely through airborne transmission, without direct physical contact of the victim with the bat itself.
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 analysed. This also applies 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 faecal droppings (guano), bats should be excluded from inhabited parts of houses.
Where rabies is not endemic, as throughout most of Western Europe, small bats can be considered harmless. Larger bats can give a nasty bite. They should be treated with the respect due to any wild animal.
Bats In Georgia
According the Georgia Dept of Natural Resources, there are 15 different species of bats that live in Georgia. Below is a list of these bats with a picture and a short narrative of the habits of each:
Gray Myotis -
Little Brown -
Big Brown -
Eastern Red -
Yellow -
Se Myotis -
Indiana -
Evening -
Seminole -
Silver Haired -
Small Poda -
Long Hair -
Free Tail -
Hoary -
Rafinesques Big Eared