bat

Megachiroptera
Microchiroptera
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There are estimated to be about 1,100 species of bats worldwide, accounting for about 20% of all mammal species.

About 70 percent of bats are insectivorous. These bats include the leaf-nosed bats (Phyllostomidae) of central America and South America, and the related bulldog bats (Noctilionidae) that feed on fish. There are at least two known species of bat that feed on other bats: the Spectral Bat or American False Vampire bat and the Ghost Bat of Australia.

Some of the smaller bat species are important pollinators of some tropical flowers.

Classification

Bats are mammals. There are two suborders of bats:

Despite the name, not all megabats are larger than microbats.

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

Bats are traditionally grouped with the tree shrews (Scandentia), colugos (Dermoptera), and the primates in superorder Archonta because of the similarities between Megachiroptera and these mammals. cheir, hand, + pteron, wing) Suborder Megachiroptera (megabats) Pteropodidae Suborder Microchiroptera (microbats) Superfamily Emballonuroidea Emballonuridae (Sac-winged or Sheath-tailed bats) Superfamily Rhinopomatoidea Rhinopomatidae (Mouse-tailed bats) Craseonycteridae (Bumblebee Bat or Kitti's Hog-nosed Bat) Superfamily Rhinolophoidea Rhinolophidae (Horseshoe bats) Nycteridae (Hollow-faced or Slit-faced bats) Megadermatidae (False vampires) Superfamily Vespertilionoidea Vespertilionidae (Vesper bats or Evening bats) Superfamily Molossoidea Molossidae (Free-tailed bats) Antrozoidae (Pallid bats) Superfamily Nataloidea Natalidae (Funnel-eared bats) Myzopodidae (Sucker-footed bats) Thyropteridae (Disk-winged bats) Furipteridae (Smoky bats) Superfamily Noctilionoidea Noctilionidae (Bulldog bats or Fisherman bats) Mystacinidae (New Zealand short-tailed bats) Mormoopidae (Ghost-faced or Moustached bats) Phyllostomidae (Leaf-nosed bats) This family contains (among others) the Vampire bats

Most microbats are active at night or at twilight. in one group (the tiger moths), the moths produce ultrasonic signals to warn the bats that the moths are chemically-protected (aposematism) (this was once thought to be a form of "radar jamming", but this theory has been disproved); in the other group (Noctuidae) the moths have a type of 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 maneuvers. Furthermore, there is some evidence that the fruit bat genus Pteralopex, which occurs in the Solomon Islands, and its close relative Mirimiri from Fiji, have evolved to fill some niches that were open because there are no nonvolant mammals in those islands.

While other mammals have one-way valves only in their veins to prevent the blood from flowing backwards, bats also have the same mechanism in their arteries.

The finger bones of a bat are much more flexible than those of other mammals.

Because their wings are much thinner than those of birds, bats can maneuver more quickly and more precisely than birds. But these sensitive areas are different in bats as each bump has a tiny hair in the center, making it even more sensitive, and allowing the bat to detect and collect information about the air flowing over its wings. The cells are concentrated in areas of the membrane where insects hit the wings when the bats capture them.

More about microbat vision

Reproduction

Mother bats usually have only one offspring per year. Bats often form nursery roosts, with many females giving birth in the same area, be it a cave, a tree hole, or a cavity in a building.

A single bat can live over 20 years, but the bat population growth is limited by the slow birth rate.

Habits and behaviour

Bats vary in social structure, with some bats leading a solitary life and others living in caves colonized by more than a million bats.

The fission-fusion social structure is seen among several species of bats. The fission part is the breaking apart and mixing of subgroups by switching roosts with bats, ending up with bats in different trees and often with different roostmates.

Studies also show that bats make all kinds of sounds to communicate with others. Scientists in the field have listened to bats and have been able to identify some sounds with some behavior bats will make right after the sounds are made.

Vectors for pathogens

Bats are natural reservoirs or vectors for a large number of zoonotic pathogens including rabies, SARS, Henipavirus (ie. Their high mobility, broad distribution, social behaviour (communal roosting, fission-fusion social structure) and close evolutionary relationship to humans make bats favourable hosts and disseminators of disease.

The following advice is only relevant to areas with endemic rabies.

Only 0.5% of bats carry rabies. 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. 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.

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.

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.

Where rabies is not endemic, as throughout most of western Europe, small bats can be considered harmless.

Cultural aspects

The bat is sacred in Tonga and West Africa 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.

In Western Culture, the bat is often a symbol of the night and its foreboding nature. A likely root to this myth is that insect-eating bats seeking prey may dive erratically toward people, who attract mosquitoes and gnats, leading the squeamish to believe that the bats are trying to get in their hair.

In the United Kingdom all bats are protected under the Wildlife and Countryside Acts, and even disturbing a bat or its roost can be punished with a heavy fine.

Austin, Texas is the summer home to North America's largest urban bat colony, an estimated 1,500,000 Mexican free-tailed bats, who eat an estimated 10,000 to 30,000 pounds of insects each night and attract 100,000 tourists each year.

In Sarawak, Malaysia bats are protected species under the Wildlife Protection Ordinance 1998 (see Malaysian Wildlife Law). The large Naked bat (see Mammals of Borneo) and Greater Nectar bat are consumed by the local communities.

Some people enjoy bat bathing; standing at an opening to a cave they wait until the bats leave, surrounding them in a 'sea' of bats.

Bat houses

Many people put up bat houses to attract bats just as many people put up bird houses.

Bat houses can be made from scratch, made from kits, or bought ready made. Plans for bat houses exist on many web sites, as well as guidelines for designing your own bat house.

A bat house constructed in 1991 at the University of Florida campus in Gainesville has a population of over 100,000 free-tailed bats.

Some conservation societies are giving away free bat houses to bat enthusiasts worldwide.