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Bat

2007 Schools Wikipedia Selection. Related subjects: Mammals

      iBats

                    Fossil range: Late Paleocene - Recent

   "Chiroptera" from Ernst Haeckel's Kunstformen der Natur, 1904
   "Chiroptera" from Ernst Haeckel's Kunstformen der Natur, 1904
                     Scientific classification

   Kingdom: Animalia
   Phylum:  Chordata
   Class:   Mammalia
   Order:   Chiroptera
            Blumenbach, 1779

                                  Suborders

   Megachiroptera
   Microchiroptera
   See text for families.

   Bats are mammals in the order Chiroptera. Their most distinguishing
   feature is that their forelimbs are developed as wings, making them the
   only mammal in the world naturally capable of flight; other mammals,
   such as flying squirrels and gliding phalangers, can glide for limited
   distances but are not capable of true sustainable flight. The word
   Chiroptera can be translated from the Greek words for "hand 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.

   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. Most of the remainder feed
   on fruits and their juices; three bat species sustain themselves with
   blood and some prey on vertebrates. 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. Indeed, many tropical plants are now found to be
   totally dependent on them, not just for pollination, but for spreading
   their seeds by eating the resulting fruits. This role explains
   environmental concerns when a bat is introduced in a new setting.
   Tenerife provides a recent example with the introduction of the
   Egyptian fruit bat.

Classification

   Townsends's Big-eared Bat, Corynorhinus townsendii
   Enlarge
   Townsends's Big-eared Bat, Corynorhinus townsendii
   Giant golden-crowned flying fox, Acerodon jubatus
   Enlarge
   Giant golden-crowned flying fox, Acerodon jubatus
   Parti-coloured bat, Vespertilio murinus
   Enlarge
   Parti-coloured bat, Vespertilio murinus
   Common Pipistrelle, Pipistrellus pipistrellus
   Enlarge
   Common Pipistrelle, Pipistrellus pipistrellus

   Bats are mammals. Though sometimes called "flying rodents", "flying
   mice," or even mistaken for bugs and birds, bats are neither mice nor
   rodents, and certainly not arthropods. There are two suborders of bats:
    1. Megachiroptera (megabats)
    2. Microchiroptera (microbats/echolocating bats)

   Despite the name, not all megabats are larger than microbats. The major
   distinction between the two suborders is based on other factors:
     * Microbats use echolocation, whereas megabats do not (except for
       Rousettus and relatives, which do).
     * Microbats lack the claw at the second toe of the forelimb.
     * The ears of microbats don't form a closed ring, but the edges are
       separated from each other at the base of the ear.
     * Microbats lack underfur; they have only guard hairs or are naked.

   Megabats eat fruit, nectar or pollen while microbats eat insects, blood
   (small quantities of blood of animals), small mammals, and fish,
   relying on echolocation for navigation and finding prey.

   Genetic evidence, however, indicates that some microbats
   ("Yinochiroptera") are more closely related to megabats than to the
   other microbats ("Yangochiroptera"). There is some morphological
   evidence that Megachiroptera evolved flight separately from
   Microchiroptera; if so, the Microchiroptera would have uncertain
   affinities. When adaptations to flight are discounted in a cladistic
   analysis, the Megachiroptera are allied to the primates by anatomical
   features that are not shared with Microchiroptera.

   Little is known about the evolution of bats, since their small,
   delicate skeletons do not fossilize well. However a late Cretaceous
   tooth from South America resembles that of an early Microchiropteran
   bat. 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. Archaeopteropus, formerly classified as
   the earliest known megachiropteran, is now classified as a
   microchiropteran.

   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. However,
   molecular studies have placed them as sister group to Ferungulata, a
   large grouping including carnivorans, pangolins, odd-toed ungulates,
   even-toed ungulates, and whales.
     * ORDER CHIROPTERA (Ky-rop`ter-a) (Gr. cheir, hand, + pteron, wing)
          + Suborder Megachiroptera ( megabats)
               o Pteropodidae
          + Suborder Microchiroptera ( microbats)
               o Superfamily Emballonuroidea
                    # Emballonuridae ( Sac-winged or Sheath-tailed bats)
               o Superfamily Rhinopomatoidea
                    # Rhinopomatidae ( Mouse-tailed bats)
                    # Craseonycteridae ( Bumblebee Bat or Kitti's
                      Hog-nosed Bat)
               o Superfamily Rhinolophoidea
                    # Rhinolophidae ( Horseshoe bats)
                    # Nycteridae ( Hollow-faced or Slit-faced bats)
                    # Megadermatidae ( False vampires)
               o Superfamily Vespertilionoidea
                    # Vespertilionidae ( Vesper bats or Evening bats)
               o Superfamily Molossoidea
                    # Molossidae ( Free-tailed bats)
                    # Antrozoidae ( Pallid bats)
               o Superfamily Nataloidea
                    # Natalidae ( Funnel-eared bats)
                    # Myzopodidae ( Sucker-footed bats)
                    # Thyropteridae ( Disk-winged bats)
                    # Furipteridae ( Smoky bats)
               o 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. By emitting
   high-pitched sounds and listening to the echoes, the microbats locate
   prey and other nearby objects. This is the process of echolocation, a
   skill they share with dolphins and whales. But although the eyes of
   most species of microbats are small and poorly developed, the sense of
   vision is typically very good, especially at long distances, beyond the
   range of echolocation. Their senses of smell and hearing, however, are
   excellent. A few moths have exploited the bat's senses; 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.

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

   Megabats are primarily fruit- or nectar-eating. They have, however,
   probably evolved for some time in New Guinea without microbat
   concurrention. This has resulted in some smaller megabats of the genus
   Nyctimene becoming (partly) insectivorous to fill the vacant microbat
   ecological niche. 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.
   Thermographic image of a bat using trapped air as insulation.
   Enlarge
   Thermographic image of a bat using trapped air as insulation.

   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. One reason is that the cartilage in their fingers lacks
   calcium and other minerals nearer the tips, increasing their ability to
   bend without splintering. The cross section of the finger bone is also
   flattened instead of circular as is the bone in a human finger, making
   it even more flexible. The skin on their wing membranes is a lot more
   elastic and can stretch much more than what is usually seen among
   mammals.

   Because their wings are much thinner than those of birds, bats can
   maneuver more quickly and more precisely than birds. The surface of
   their wings are also equipped with touch-sensitive receptors on small
   bumps called Merkel cells, found in most mammals, including humans. But
   these sensitive areas are different in bats as each bump has a tiny
   hair in the centre, making it even more sensitive, and allowing the bat
   to detect and collect information about the air flowing over its wings.
   An additional kind of receptor cell is found in the wing membrane of
   species that use their wings to catch prey. This receptor cell is
   sensitive to the stretching of the membrane. The cells are concentrated
   in areas of the membrane where insects hit the wings when the bats
   capture them.

   More about microbat vision

Reproduction

   Colony of Mouse-eared Bats, Myotis myotis
   Enlarge
   Colony of Mouse-eared Bats, Myotis myotis

   Mother bats usually have only one offspring per year. A baby bat is
   referred to as a pup. Pups are usually left in the roost when they are
   not nursing. However, a newborn bat can cling to the fur of the mother
   and be transported, although they soon grow too large for this. It
   would be difficult for an adult bat to carry more than one young, but
   normally only one young is born. 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. Mother bats are able to find their young in
   huge colonies of millions of other pups. Pups have even been seen to
   feed on other mothers' milk if their mother is dry. Only the mother
   cares for the young, and there is no continuous partnership with male
   bats.

   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.

   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 fusion part is all the individuals in a roosting area. 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 behaviour 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. Nipah virus and
   Hendra virus), West Nile virus and possibly ebola virus. 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. Many
   species also appear to have a high tolerance for harbouring pathogens
   and often do not develop disease while infected.
   A big brown bat (Eptesicus fuscus) approaches a wax moth (Galleria
   mellonella), which serves as the control species for the studies of the
   tiger moths. The moth is only "semi-tethered," allowing it to fly
   evasively.
   Enlarge
   A big brown bat (Eptesicus fuscus) approaches a wax moth (Galleria
   mellonella), which serves as the control species for the studies of the
   tiger moths. The moth is only "semi-tethered," allowing it to fly
   evasively.

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

   Only 0.5% of bats carry rabies. However, 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 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 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 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 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. In certain countries, such as the UK, it is
   illegal to handle bats without a license.

   Where rabies is not endemic, as throughout most of western Europe,
   small bats can be considered harmless. Larger bats can give a nasty
   bite. Treat them with the respect due to any wild animal.

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. 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 geographical
   Macedonia and among the Kwakiutl and Arabs.

   In Western Culture, the bat is often a symbol of the night and its
   foreboding nature. The bat is a primary animal associated with
   fictional characters of the night such as both villains like Dracula
   and heroes like Batman. The association of the fear of the night with
   the animal was treated as a literary challenge by Kenneth Oppel, who
   created a best selling series of novels, beginning with Silverwing,
   which feature bats as the central heroic figures much in a similar
   manner as the classic novel Watership Down did for rabbits. An old
   wives' tale has it that bats will entangle themselves in people's hair.
   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. Reasons for this vary, but mostly centre around the
   fact that bats are the primary nocturnal insectivores in most if not
   all ecologies.

   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.

   Retrieved from " http://en.wikipedia.org/wiki/Bat"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
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