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Bat

Bat


Antrozoidae
Craseonycteridae
Emballonuridae
Furipteridae
Megadermatidae
Molossidae
Mormoopidae
Mystacinidae
Myzopodidae
Natalidae
Noctilionidae
Nycteridae
Phyllostomidae
Pteropodidae
Rhinolophidae
Rhinopomatidae
Thyropteridae
Vespertilionidae
Bats are flying mammals in the Chiroptera order with forelimbs developed as wings. Other mammals, such as flying squirrels or gliding phalangers, can glide limited distances, but only bats are capable of true flight. The name Chiroptera can be translated from the Greek term for Hand Wing, as the structure of the open wing is very similar to an outspread human hand, with a membrane between the fingers that also stretches between hand and body. Though the vast majority of bats are insectivorous, a significant number from both suborders, Megachiroptera and Microchiroptera (see below), feed on fruits and their juices. Few bats drink blood but some prey on vertebrates. These bats include the Leaf-nosed bats (Phyllostomidae) of Central and South America, and the allied family Noctilionidae (Bulldog bats) that feed on fish.The Ghost Bat of Australia is one example of a carnivorous bat that even feeds on other bats. Some of the smaller species are important pollinators of some tropical flowers. Indeed, many tropical plants are now found to be totally dependent on them, not just as pollinators, but eating the resulting fruits and so spreading their seeds. This role explains environmental concerns when an exotic bat is introduced in a new setting. Tenerife provides a recent and particularly interesting example here, given the island's unique flora and fauna (much of it vestiges of the ancient continent of Gondwana). In this case, the exotic bat threatening native species is the Egyptian Bat (Roussettus aegyptiacus) [http://www.atan.org/en/animales/loroparque/murcielago.htm 1].

Classification

Though sometimes called "flying rodents" or "flying mice," these terms are erroneous, as bats are neither mice nor rodents. There are two suborders of bats: # Megachiroptera (megabats or fruit bats) # Microchiroptera (microbats, echolocating bats or insectivorous bats) Megabats eat fruit, nectar or pollen while microbats eat insectss, blood (small quantities of blood of animals), small mammals, and fish, relying on echolocation for navigation and finding prey. There is controversial but well-supported 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. Some genetic evidence, however, has pointed to the common ancestry of Megachiroptera and at least some Microchiroptera. Other genetic evidence points to Chiroptera diphyly microbat polyphyly. Most studies of eutherian relationships have attempted to avoid this issue by assuming monophyly of Chiroptera. 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 usually grouped with the tree shrews (Scandentia), colugos (Dermoptera), and the primates in superorder Archonta because of the similarities between Megachiroptera and these mammals.
- ORDER CHIROPTERA
  - 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, so the eyes of most species of microbats are poorly developed. Their senses of smell and hearing, however, are excellent. 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. The teeth of microbats resemble those of the insectivores. They are very sharp in order to bite through the chitin armour of insects or the skin of fruits. 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 much more elastic and can stretch much more than what is usually seen among mammals. Because their wings are much thinner than those of of birds, bats can maneuver more quickly and more precisely than birds.

Reproduction

arteries] 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. Two mammary glands are situated between the chest and the shoulders. 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.

Habits and Behavior

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 each other. 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.

Enemies

Small bats are sometimes preyed upon by owls and falcons. Generally there are few animals able to hunt a bat. In Asia there is a bird, the bat hawk, which specializes in hunting bats. The domestic cat is a regular predator in urban areas; they may catch bats as they enter or leave a roost, or on the ground. Bats will land on the ground for feeding, in bad weather, or due to accidents while learning to fly. 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 fly. In their caves the bats hang close together, so it is easy for the parasites to infect new hosts. The most destructive enemy of bats is probably humans, who fear the harmless animal either because of superstition or fear of rabies. Destruction of bat habitat and elimination of their food source (primarily insects) negatively affects the species.

Vector for rabies

insects 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 [http://www.cdc.gov/ncidod/dvrd/rabies/Bats_&_Rabies/bats&.htm 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 as harmless. Larger bats can give a nasty bite. Treat them with the respect due to any wild animal.

References


- Greenhall, Arthur H. 1961. Bats in Agriculture. A Ministry of Agriculture Publication. Trinidad and Tobago.
- Nowak, Ronald M. 1994. " Walker's BATS of the World". The John Hopikins University Press, Baltimore and London.

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 forboding 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 Oppell, 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.

References


- [http://www.uq.edu.au/nuq/jack/consensus.htm John D. Pettigrew's summary on Flying Primate Hypothesis]

See also


- European Bat Night
- Bat bomb
- Batman
- Bat World Sanctuary
- Fictional bats

External links


- [http://www.batworld.org/local_rescue/local_rescue.html United States Bat Rescue]
- [http://www.batcon.org Bat Conservation International website]
- [http://www.batworld.org Bat World Sanctuary]
- [http://www.tpwd.state.tx.us/nature/wild/vertebrate/mammals/bats/ Texas Parks and Wildlife Bat Page]
- [http://animaldiversity.ummz.umich.edu/chordata/mammalia/chiroptera.html University of Michigan Museum of Zoology]
- [http://tolweb.org/tree?group=Chiroptera&contgroup=Eutheria Tree of Life]
- [http://flyingfur.typepad.com/ Flying Fur]
- [http://seekmybowl.com/bat.php Seek My Bowl on bat as symbol.]
- [http://news.bbc.co.uk/2/hi/science/nature/4213495.stm Bats make up 20% of mammals]
- [http://www.bats.org.uk The Bat Conservation Trust]
- [http://www.batworld.org/adopt_a_bat/adopt_a_bat.html Adopt-a-Bat]
- [http://www.batconservation.org Organization for Bat Conservation]
- [http://www.uni-tuebingen.de/tierphys/Kontakt/mitarbeiter_seiten/dietz.htm Illustrated Identification key to the (micro)bats of Europe] (see "Recent publications") ko:박쥐 ja:コウモリ simple:Bat

Emballonuridae


Balantiopteryx
Centronycteris
Coleura
Cormura
Cyttarops
Diclidurus
Emballonura
Mosia
Peropteryx
Rhynchonycteris
Saccolaimus
Saccopteryx
Taphozous The sac-winged or sheath-tailed bats constitute a family, Emballonuridae, of 47 species of bats. They can be found in tropical and sub-tropical regions all over the world. Emballonurids are small, and generally brown or grey; however, the ghost bats (genus Diclidurus) are white. Category:Bats

Furipteridae


Furipteridae, also known as Smoky Bats or Thumbless Bats, is a small group of bats from Central and South America, closely related to Natalidae and Thyropteridae bat families. They can be recognized by their reduced thumb, enclosed by the wing membranes. There are only two genera in the group, each with a single species. They are insectivorous and can live in many different kinds of environments.

Taxonomy


- Genus Amorprochilus
  - Amorphochilus schnablii, Smoky Bat
- Genus Furipterus
  - Furipterus horrens, Thumbless Bat Category:Bats

Mormoopidae


Mustached bats are a small group of bats of the family Mormoopidae. They are found in Central and South America, from Southern Mexico to Southeastern Brazil. It`s a small family, consisting of a single genus with three species. There are two genera and around 13 species in this family. They roost in caves and tunnels and feed on insects while they are flying.

Taxonomy


- Genus Mormoops
- Genus Pteronotus Category:Bats

Bulldog bat



The Noctilionidae family of bats, commonly known as Bulldog bats, are represented by two species, the Greater Bulldog Bat and the Lesser Bulldog Bat. The Naked Bulldog Bat, Cheiromeles torquatus is not of this family and belongs to the family Molossidae, the free-tailed bats. Category:Bats

Nycteridae

Nycteridae is the family of slit-faced or hollow-faced bats. They are grouped in a single genus, Nycteris. The bats are found in East Malaysia, Indonesia and many parts of Africa.

Classification

Most sources report 13 species. However 16 have been described. Those of indeterminate status are marked with "?" in the list below. Familia Nycteridae Van der Hoeven , 1855
- Nycteris G. Cuvier & E. Geoffroy Saint-Hilaire, 1795
- Nycteris arge Thomas , 1903
- Nycteris aurita K. Andersen , (1912)
- Nycteris gambiensis Andersen , (1912)
- Nycteris grandis Peters , 1865
- Nycteris hispida Schreber , (1775)
  - Nycteris hispida hispida
  - Nycteris hispida pallida
- Nycteris intermedia Aellen ,1959
- Nycteris javanica E. Geoffroy Saint-Hilaire ,1813
- Nycteris macrotis Dobson ,1876
  - Nycteris macrotis aethiopica
  - Nycteris macrotis macrotis Dobson ,1876
  - Nycteris macrotis luteola
- Nycteris vinsoni Dalquest ,1965?
- Nycteris madagascariensis Grandidier ,1937?
- Nycteris major Andersen ,(1912)
  - Nycteris major avakubia
  - Nycteris major major
- Nycteris nana Andersen ,(1912)
  - Nycteris nana nana
  - Nycteris nana tristis
- Nycteris thebaica E. Geoffroy Saint-Hilaire ,1818
  - Nycteris thebaica adana
  - Nycteris thebaica albiventer
  - Nycteris thebaica capensis
  - Nycteris thebaica damarensis
  - Nycteris thebaica najdiya Kock & Nader ,1983
  - Nycteris thebaica thebaica
- Nycteris tragata Andersen ,(1912)
  - Nycteris parisii De Beaux ,1924?
  - Nycteris woodi Andersen ,1914

References


- http://www.funet.fi/pub/sci/bio/life/mammalia/chiroptera/nycteridae/nycteris/ Data from funet.ni] Category:Bats

Leaf-nosed bat


Ametrida
Anoura
Ardops
Ariteus
Artibeus
Brachyphylla
Carollia
Centurio
Chiroderma
Choeroniscus
Choeronycteris
Chrotopterus
Desmodus
Diaemus
Diphylla
Ectophylla
Erophylla
Glossophaga
Hylonycteris
Leptonycteris
Lichonycteris
Lionycteris
Lonchophylla
Lonchorhina
Macrophyllum
Macrotus
Micronycteris
Mimon
Monophyllus
Musonycteris
Phylloderma
Phyllonycteris
Phyllops
Phyllostomus
Platalina
Pygoderma
Rhinophylla
Scleronycteris
Sphaeronycteris
Stenoderma
Sturnira
Tonatia
Trachops
Uroderma
Vampyressa
Vampyrodes
Vampyrops
Vampyrum The Leaf-nosed bats, family Phyllostomidae are by far the most varied and diverse within the whole order Chiroptera and count within their number true predatory species that take vertebrate prey including small Dove -sized birds in the case of the False Vampire, Vampyrum spectrum, the largest bat in the Americas. Within the group, species have evolved to utilize food groups such as fruit, nectar, pollen, insects, frogs, other bats and small vertebrates, and closely allied families that feed on fish Noctilionidae and the three highly specialised species that feed on blood. The family gets its name from the often large, lance shaped nose projection used to direct their sonar, though some of the nectar/pollen feeders have greatly reduced it. There are 148 species within 48 genera which are listed below. The representative genera:
- Ametrida
- Anoura (Geoffroy's Long-nosed Bats)
- Ardops (Tree Bat)
- Ariteus (Jamaican Fig-eating Bat)
- Artibeus (Neotropical Fruit Bats)
- Brachyphylla
- Carollia (Short-tailed Leaf-nosed Bats)
- Centurio (Wrinkle-faced Bat, Or Lattice-winged Bat)
- Chiroderma (Big-eyed Bats, Or White-lined Bats)
- Choeroniscus
- Choeronycteris (Mexican Long-nosed Bat, Or Hog-nosed Bat)
- Chrotopterus (Peters's Woolly False Vampire Bat)
- Desmodus (Common Vampire Bat)
- Diaemus (White-winged Vampire Bat)
- Diphylla (Hairy-legged Vampire Bat)
- Ectophylla (White Bat)
- Erophylla (Brown Flower Bats)
- Glossophaga
- Hylonycteris (Underwood's Long-tongued Bat)
- Leptonycteris (Saussure's Long-nosed Bats)
- Lichonycteris
- Lionycteris
- Lonchophylla
- Lonchorhina (Sword-nosed Bats)
- Macrophyllum (Long-legged Bat)
- Macrotus (Big-eared Bats)
- Micronycteris (Little Big-eared Bats)
- Mimon (Gray's Spear-nosed Bats)
- Monophyllus
- Musonycteris (Banana Bat, Or Colima Long-nosed Bat)
- Phylloderma (Peters's Spear-nosed Bat)
- Phyllonycteris
- Phyllops (Falcate-winged Bats)
- Phyllostomus (Spear-nosed Bats)
- Platalina
- Pygoderma (Ipanema Bat)
- Rhinophylla
- Scleronycteris
- Sphaeronycteris
- Stenoderma (Red Fruit Bat)
- Sturnira (Yellow-shouldered Bats, Or American Epauleted Bats)
- Tonatia (Round-eared Bats)
- Trachops (Frog-eating Bat)
- Uroderma (Tent-building Bats)
- Vampyressa (Yellow-eared Bats)
- Vampyrodes (Great Stripe-faced Bat)
- Vampyrops (White-lined Bats)
- Vampyrum (Linnaeus's False Vampire Bat, Or Spectral Vampire) Category:Bats

Horseshoe bat


Horseshoe bats (family Rhinolophidae) are a large family of bats including approximately 130 species grouped in 10 genera. They belong to the suborder Microchiroptera (microbats). The Rhinolophidae family is sometimes divided into two families, the Rhinolophidae (horse-shoe bats) and Hipposideridae (Old World leaf-nosed bats). There is little question that these two groups of bats are closely related, but current practise is to classify them as subfamilies (Hipposiderinae and Rhinolophinae) in a single family. Many species are extremely difficult to distinguish. All rhinolophids have leaf-like protuberances on their noses. In rhinolophines species, these take the shape of a horseshoe; in hipposiderine, they are leaf- or spear-like. They emit echolocation calls through these structures, which may serve to focus the sound. Most rhinolophids are dull brown or reddish brown in color. They vary in size from small to moderately large. Rhinolophids inhabit temperate and tropical regions of southern Europe, Africa, and Asia south to northern and eastern Australia, including many Pacific islands. All species are insectivorous, capturing insects in flight. Their roost habits are diverse; some species are found in large colonies in caves, some prefer hollow trees, and others sleep in the open, among the branches of trees. Members of northern populations may hibernate during the winter; at least one species is migratory. Like many Vespertilionidae bats, females of some rhinolophid species mate during the fall and store the sperm over the winter, conceiving and gestating young beginning in the spring.
- Subfamily Rhinolophinae
  - Genus Rhinolophus (horseshoe bats)
- Subfamily Hipposiderinae
  - Genus Anthops (flower-faced bat)
  - Genus Asellia (trident leaf-nosed bats)
  - Genus Aselliscus (Tate's trident-nosed bats)
  - Genus Cloeotis (Percival's trident bat)
  - Genus Coelops (tailless leaf-nosed bats)
  - Genus Hipposideros (round leaf bats)
  - Genus Paracoelops (Vietnam leaf-nosed bat)
  - Genus Rhinonicteris (orange leaf-nosed bat)
  - Genus Triaenops (triple leaf-nosed bats) Category:Bats

Thyropteridae


Disc-winged bats are a small group of bats of the family Thyropteridae. They are found in Central and South America, usually in moist tropical rain forests. It`s a very small family, consisting of a single genus with three species. The name comes from the suction cups found at the base of the thumb and under the heel of these animals, similar to those found in Myzopodidae bats. These structures help them to cling smooth surfaces, and to remain, for example, inside of young coiled banana and heliconia leaves, where they roost. They can be recognized by their reduced thumb, enclosed by the wing membranes. There are only two genera in the group, each with a single species. They are insectivorous and can live in many different kinds of environments.

Taxonomy


- Genus Thyroptera
  - Thyroptera discifera
  - Thyroptera tricolor
  - Thyroptera lavali Category:Bats

Flying

Flight is the process of flying: either movement through the air by aerodynamically generating lift or aerostatically using buoyancy, or movement beyond earth's atmosphere by spacecraft.

Animal flight

spacecraft The most successful groups of living things that fly are insects, birds, and bats. Each of these groups' wings evolved separately from different structures. Pterosaurs were a group of flying vertebrates contemporaneous with the dinosaurs. Bats are the only mammals capable of true flight. However, there are several gliding mammals which are able to glide from tree to tree using fleshy membranes between their limbs; some can travel hundreds of metres in this way with very little loss of height. Flying tree frogs use greatly enlarged webbed feet for a similar purpose, and there are flying lizards which employ their unusually wide, flattened rib-cages to the same end. Certain snakes also use a flattened rib-cage to fly, with a back and forth motion much the same as they use on the ground. Flying fish can glide using enlarged wing-like fins, and have been observed soaring for hundreds of metres using the updraft on the leading edges of waves. It is thought that they evolved this ability to help them escape from underwater predators. Most birds fly (see bird flight), with some exceptions. The largest birds, the ostrich and the emu, are earthbound, as were the now-extinct dodos, while the non-flying penguins have adapted their wings for use under water. Most small flightless birds are native to small islands, and lead a lifestyle where flight would confer little advantage. The Peregrine Falcon is the fastest animal in the world; its terminal velocity exceeds 320 km/h (199 mph) while diving down on its prey. Among living animals that fly, the wandering albatross has the greatest wingspan, up to 3.5 metres (11.5 feet), and the trumpeter swan perhaps the greatest weight, at 17 kilograms (38 pounds). Among the many species of insects, some fly and others do not (See insect flight).

In fiction


- Dumbo, the Disney-created elephant, employs his comically oversized ears as wings for flight.
- Many dragons are depicted with wings capable of flight.
- Superman is a well known superhero in comic books, cartoons, and films; unaided flight is among the various super powers he is portrayed to obtain from the yellow rays of earth's sun. Most flight-capable fictional comic book superheroes are said to fly by sheer will rather than by telekinetically levitating themselves. Jean Grey of the X-men is an exception who uses telekinesis to levitate slightly above ground. telekinesis

Mechanical flight

Flying machines are aircraft, including aeroplanes, helicopters, airships and balloons, and spacecraft. In the case of an aeroplane flight involves
- Taxiing
- Take off
- Climb
- Cruise
- Descent
- Landing See aviation history for the history of mechanical flight.

See also


- Amelia Earhart
- Alberto Santos-Dumont
- Armen Firman
- Aviation
- Aircraft
- Charles Lindbergh
- Instrument Flight Rules
- Levitation
- Model aircraft
- Ornithopter
- Public transport service numbering
- Visual flight
- Visual Flight Rules
- Wright Brothers Category:Aerodynamics

Mammal



- Subclass Multituberculata (extinct)
  - Plagiaulacida
  - Cimolodonta
- Subclass Palaeoryctoides (extinct)
- Subclass Triconodonta (extinct)
- Subclass Eutheria (includes extinct ancestors)/Placentalia (excludes extinct ancestors)
  - Afrosoricida
  - Artiodactyla
  - Carnivora
  - Cetacea
  - Chiroptera
  - Cimolesta (extinct)
  - Creodonta (extinct)
  - Condylarthra (extinct)
  - Dermoptera
  - Desmostylia (extinct)
  - Embrithopoda (extinct)
  - Hyracoidea
  - Insectivora
  - Lagomorpha
  - Litopterna (extinct)
  - Macroscelidea
  - Mesonychia (extinct)
  - Notoungulata (extinct)
  - Perissodactyla
  - Pholidota
  - Plesiadapiformes (extinct)
  - Primates
  - Proboscidea
  - Rodentia
  - Scandentia
  - Sirenia
  - Taeniodonta (extinct)
  - Tillodontia (extinct)
  - Tubulidentata
  - Xenarthra
- Subclass Marsupialia
  - Dasyuromorphia
  - Didelphimorphia
  - Diprotodontia
  - Microbiotheria
  - Notoryctemorphia
  - Paucituberculata
  - Peramelemorphia
- Subclass Monotremata
  - Monotremata The mammals are the class of vertebrate animals characterized by the presence of mammary glands, which in females produce milk for the nourishment of young; the presence of hair or fur; and which have endothermic or "warm-blooded" bodies. The brain regulates endothermic and circulatory systems, including a four-chambered heart. Mammals encompass some 5500 species, distributed in about 1200 genera, 152 families and up to 46 orders, though this varies depending on the classification scheme adopted. Phylogenetically, Mammalia is defined as all of the descendants of the last common ancestor of monotremes (e.g., echidnas) and therian mammals (placentals and marsupials).

Characteristics

While most mammals give birth to live young, there are a few mammals (the monotremes) that lay eggs. Live birth also occurs in a variety of non-mammalian species, such as guppies and hammerhead sharks; thus it is not a distinguishing characteristic of mammals. Although all mammals are endothermic, so are birds and so this is also not a main defining feature. While monotremes do not have nipples, they do have mammary glands, meaning that they meet all conditions for inclusion in the class Mammalia. It should be noted that the current trend in taxonomy is to emphasize common ancestry; the diagnostic characteristics are useful for identifying this ancestry, but if, for example, a cetacean were found that had no hair at all, it would still be classified as a mammal. Mammals have three bones in each ear and one (the dentary) on each side of the lower jaw; all other vertebrates with ears have one bone (the stapes) in the ear and at least three on each side of the jaw. A group of therapsids called cynodonts had three bones in the jaw, but the main jaw joint was the dentary and the other bones conducted sound. The extra jaw bones of other vertebrates are thought to be homologous with the malleus and incus of the mammal ear. All mammalian brains possess a neocortex. This brain region is unique to mammals. Mammals have integumentary systems made up of three layers: the outermost epidermis, the dermis, and the hypodermis. The epidermis is typically ten to thirty cells thick, its main function being to provide a waterproof layer. Its outermost cells are constantly lost; its bottommost cells are constantly dividing and pushing upward. The middle layer, the dermis, is fifteen to forty times thicker than the epidermis. The dermis is made up of many components such as bony structures and blood vessels. The hypodermis is made up of adipose tissue. Its job is to store lipids, and to provide cushioning and insulation. The thickness of this layer varies widely from species to species. Most mammals are terrestrial, but a number are aquatic, including sirenia (manatees and dugongs) and the cetaceans (dolphins and whales). Whales are the largest of all animals. There are semi-aquatic species such as seals which come to land to breed but spend the majority of the time in water. True flight has evolved only once in mammals, the bats; mammals such as flying squirrels and flying lemurs are actually gliding animals. No mammals have hair naturally blue or green in colour. Some cetaceans, along with the mandrills appear to have shades of blue skin. Many mammals are indicated as having blue hair or fur, but in all cases, it will be found to be a shade of grey. The two-toed sloth can seem to have green fur, however, this colour is caused by algae growths.

Origins

Mammals belong among the amniotes, and in particular to a group called the synapsids, distinguished by the shape of their skulls, in particular the presence of a single hole where jaw muscles attach, called temporal fenestra. In comparison, dinosaurs, birds, and most reptiles are diapsids, with two temporal fenestrae; and turtles, with no temporal fenestra, are anapsids. From synapsids came the first mammal precursors, therapsids, and more specifically the eucynodonts, 220 million years ago (mya) during the Triassic period. Pre-mammalian ears began evolving in the late Permian to early Triassic to their current state, as three tiny bones (incus, malleus, and stapes) inside the skull; accompanied by the transformation of the lower jaw into a single bone. Other animals, including reptiles and pre-mammalian synapsids and therapsids, have several bones in the lower jaw, some of which are used for hearing; and a single ear-bone in the skull, the stapes. This transition is evidence of mammalian evolution from reptilian beginnings: from a single ear bone, and several lower jaw bones (for example the sailback pelycosaur, Dimetrodon) to progressively smaller "hearing jaw bones" (for example the cynodont, Probainognathus), and finally (possibly with Morganucodon, but definitely with Hadrocodium), true mammals with three ear bones in the skull and a single lower jaw bone. Hence pelycosaurs and cynodonts are sometimes called "mammal-like reptiles", though this is strictly incorrect since in modern parlance these two are not reptiles, but rather synapsids. During the Mesozoic Period mammals diversified into four main groups: multituberculates, monotremes, marsupials, and placentals. Multituberculates went extinct during the Oligocene, about 30 million years ago, but the three other mammal groups are all represented today. Most early mammals remained small and shrew-like throughout the Mesozoic, but rapidly developed into larger more diverse forms following the Cretaceous-Tertiary extinction event 65 mya. The names "Prototheria", "Metatheria" and "Eutheria" expressed the theory that Placentalia were descendants of Marsupialia, which were in turn descendants of Monotremata, but this theory has been refuted. However, Eutheria and Metatheria are often used in paleontology, especially with regards to mammals of the Mesozoic. Mammal evolutionary progression is below:
- Jawless fish: Cambrian period to mid Ordovician periods
- Bony fish: mid-Ordovician period to late Devonian period
- Amphibians: late Devonian period to early Carboniferous period
- Reptiles: late Carboniferous period
- Pelycosaurs (synapsids, or "mammal-like reptiles"): late Carboniferous period to very early Triassic period
- Cynodonts: Permian-Triassic
- Mammals: mid-Triassic period to today

In the Mesozoic

Most early mammals were small shrew-like animals that fed on insects. However, in January 2005, the discovery was reported of two fossils of Repenomamus around 130 million years old, one more than a meter in length, the other having remains of a baby dinosaur in its stomach (Nature, Jan. 15, 2005 [http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v433/n7022/full/433116b_fs.html].) The earliest mammals include:
- Eozostrodon: Triassic and Jurassic
- Deltatheridium: Cretaceous
- Jeholodens: mid-Cretaceous
- Megazostrodon: late Triassic and early Jurassic
- Triconodont: Triassic to Cretaceous
- Zalambdalestes: late Cretaceous Although mammals existed alongside the dinosaurs, mammals only began to dominate after the mass extinction of the dinosaurs 65 mya, in the Cenozoic.

In the Paleocene

During the next 8 million years, the Paleocene period (64–58 mya), mammals exploded into the ecological niches left by the extinction of the dinosaurs. Small rodent-like mammals still dominated, but medium and larger-sized mammals evolved.
- Ptilodus: multituberculate
- Pucadelphys andinus: an opposum-like marsupial
- Purgatorius: a primate-like mammal, placental
- Ectoconus: an early hoofed mammal, placental

Classification

Main article: Mammal classification George Gaylord Simpson's classic "Principles of Classification and a Classification of Mammals" (AMNH Bulletin v. 85, 1945) was the original source for the taxonomy listed here. Simpson laid out a systematics of mammal origins and relationships that was universally taught until the end of the 20th century. Since Simpson's 1945 classification, the paleontological record has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of cladistics. Though field work gradually made Simpson's classification outdated, it remained the closest thing to an official classification of mammals.

Standardized textbook classification

A somewhat standardized classification system has been adopted by most current mammalogy classroom textbooks. The following taxonomy of extant and recently extinct mammals is taken from Vaughan et al. (2000). Class Mammalia
- Subclass Prototheria - monotremes: platypus and echidnas
- Subclass Theria - live-bearing mammals
  - Infraclass Metatheria - marsupials
  - Infraclass Eutheria - placentals

McKenna/Bell classification

In 1997, the mammals were comprehensively revised by Malcolm C. McKenna and Susan K. Bell, which has resulted in the "McKenna/Bell classification". McKenna and Bell, Classification of Mammals: Above the species level, (1997) is the most comprehensive work to date on the systematics, relationships, and occurrences of all mammal taxa, living and extinct, down through the rank of genus. The new McKenna/Bell classification was quickly accepted by paleontologists. The authors work together as paleontologists at the American Museum of Natural History, New York. McKenna inherited the project from Simpson and, with Bell, constructed a completely updated hierarchical system, covering living and extinct taxa that reflects the historical genealogy of Mammalia. The McKenna/Bell hierarchical listing of all of the terms used for mammal groups above the species includes extinct mammals as well as modern groups, and introduces some fine distinctions such as legions and sublegions (ranks which fall between classes and orders) that are likely to be glossed over by the layman. The published re-classification forms both a comprehensive and authoritative record of approved names and classifications and a list of invalid names. Click on the highlighted link for a [http://nasa.utep.edu/chih/chklist/mammals/keys/mammtab.htm table comparing the traditional and the new McKenna/Bell classifications of mammals] Extinct groups are represented by †. Class Mammalia
- Subclass Prototheria: monotremes: platypuses and echidnas
- Subclass Theriiformes: live-bearing mammals and their prehistoric relatives
  - Infraclass †Allotheria: multituberculates
  - Infraclass †Triconodonta: triconodonts
  - Infraclass Holotheria: modern live-bearing mammals and their prehistoric relatives
    - Supercohort Theria: live-bearing mammals
      - Cohort Marsupialia: marsupials
      -
- Magnorder Australidelphia: Australian marsupials and the monito-del-monte
      -
- Magnorder Ameridelphia: New World marsupials
      - Cohort Placentalia: placentals
      -
- Magnorder Xenarthra: xenarthrans
      -
- Magnorder Epitheria: epitheres
      -
  - Grandorder Anagalida: lagomorphs, rodents, and elephant shrews
      -
  - Grandorder Ferae: carnivorans, pangolins, creodonts, and relatives
      -
  - Grandorder Lipotyphla: insectivorans
      -
  - Grandorder Archonta: bats, primates, colugos, and tree shrews
      -
  - Grandorder Ungulata: ungulates
      -
    - Order Tubulidentata incertae sedis: aardvark
      -
    - Mirorder Eparctocyona: condylarths, whales, and artiodactyls
      -
    - Mirorder †Meridiungulata: South American ungulates
      -
    - Mirorder Altungulata: perissodactyls, elephants, manatees, and hyraxes

Molecular classification of mammals

Molecular studies based on DNA analysis have suggested new relationships among mammal families over the last few years. The most recent classification systems based on molecular studies have proposed four groups or lineages of placental mammals. Molecular clocks suggest that these clades diverged from early common ancestors in the Cretaceous, but fossils have not been found to corroborate this hypothesis. These molecular findings are consistent with mammal zoogeography: The first divergence was that of the Afrotheria 110–100 mya. The Afrotheria proceeded to evolve and diversify in the isolation of the African-Arabian continent. The Xenarthra, isolated in South America, diverged from the Boreoeutheria approximately 100–95 mya. The Boreoeutheria split into the Laurasiatheria and Euarchontoglires between 95 and 85 mya; both of these groups evolved on the northern continent of Laurasia. After tens of millions of years of relative isolation, Africa-Arabia collided with Eurasia, exchanging Afrotheria and Boreoeutheria. The formation of the Isthmus of Panama linked South America and North America, which facilitated the exchange of mammal species in the Great American Interchange. The traditional view that no placental mammals reached Australasia until about 5 million years ago when bats and murine rodents arrived has been challenged by recent evidence and may need to be reassessed. It should however be noted that these molecular results are still controversial because they are not reflected by morphological data and thus not accepted by many systematists.
- Group I: Afrotheria
  - Order Macroscelidea: elephant shrews (Africa).
  - Order Afrosoricida
  - Order Tubulidentata: aardvark (Africa south of the Sahara).
  - Clade Paenungulata
    - Order Hyracoidea: hyraxes, dassies (Africa, Arabia).
    - Order Proboscidea: elephants (Africa, Southeast Asia).
    - Order Sirenia
- Group II: Xenarthra
  - Order Xenarthra: sloths and anteaters (Neotropical) and armadillos (Neotropical and Nearctic)
- Clade Boreoeutheria
  - Group III Euarchontoglires
    - Superorder Euarchonta
      - Order Scandentia: tree shrews (Southeast Asia).
      - Order Dermoptera: flying lemurs or colugos (Southeast Asia).
      - Order Primates: lemurs, bushbabies, monkeys, apes (cosmopolitan).
    - Superorder Glires
      - Order Lagomorpha: pikas, rabbits, hares (Eurasia, Africa, Americas).
      - Order Rodentia: rodents (cosmopolitan)
  - Group IV: Laurasiatheria
    - Order Insectivora: eulipotyphlan insectivorans
    - Order Chiroptera: bats (cosmopolitan)
    - Order Cetartiodactyla: cosmopolitan; includes former orders Cetacea (whales, dolphins and porpoises) and Artiodactyla (even-toed ungulates, including pigs, hippopotamus, camels, giraffe, deer, antelope, cattle, sheep, goats).
    - Clade Zooamata
      - Order Perissodactyla: odd-toed ungulates
      - Clade Ferae
      -
- Order Pholidota: pangolins, scaly anteaters (Africa, South Asia).
      -
- Order Carnivora: carnivorans (cosmopolitan)

Classification system used in related articles

In light of all the options available, the following classification system has been adopted for use in related articles. Class Mammalia
- Subclass/Order Monotremata: egg-laying mammals
  - Order Monotremata: echidnas and platypus
- Subclass Marsupialia: marsupials
  - Order Didelphimorphia: New World opossums
  - Order Paucituberculata: shrew opossums
  - Order Microbiotheria: Monito del Monte
  - Order Dasyuromorphia: marsupial carnivores
  - Order Notoryctemorphia: marsupial mole
  - Superorder Syndactyla: syndactylous marsupials
    - Order Peramelemorphia: bandicoots and bilbies
    - Order Diprotodontia: koalas, wombats, kangaroos, possums, etc.
- Subclass Placentalia
  - Order Xenarthra: sloths, anteaters, armadillos
  - Order Pholidota: pangolins
  - Superorder Glires
    - Order Rodentia: rodents
    - Order Lagomorpha: rabbits, hares, and pikas
  - Order Macroscelidea: elephant shrews
  - Superorder Archonta:
    - Order Primates: primates
    - Order Scandentia: tree shrews
    - Order Chiroptera: bats
    - Order Dermoptera: colugos
  - Order Insectivora: shrews, tenrecs, moles, hedgehogs, etc.
  - Order Carnivora: dogs, cats, weasels, seals, etc.
  - Superorder Ungulata: ungulates
    - Order Tubulidentata: aardvark
    - Order Hyracoidea: hyraxes
    - Order Proboscidea: elephants
    - Order Sirenia: manatees, dugong
    - Order Perissodactyla: horses, tapirs, rhinoceroses
    - Order Artiodactyla: even-toed ungulates
    - Order Cetacea: whales

References


- McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8
- Nowak, Ronald M. 1999. Walker's Mammals of the World, 6th edition. Johns Hopkins University Press, 1936 pp. ISBN 0-801-85789-9
- Simpson, George Gaylord. 1945. "The principles of classification and a classification of mammals". Bulletin of the American Museum of Natural History, 85:1–350.
- Springer, Mark S., Michael J. Stanhope, Ole Madsen, and Wilfried W. de Jong. 2004. "Molecules consolidate the placental mammal tree". Trends in Ecology and Evolution, 19:430–438. ([http://www.zi.ku.dk/evolbiology/courses/ME04/7_9/springer200-phyl.pdf pdf version])
- Vaughan, Terry A., James M. Ryan, and Nicholas J. Capzaplewski. 2000. Mammalogy: Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0-030-25034-X (Brooks Cole, 1999)
- Wilson, Don E., and Deeann M. Reeder (eds). 1993. Mammal Species of the World. Smithsonian Institution Press, 1206 pp. ISBN 1-560-98217-9

See also


- List of mammals
- List of regional mammals lists
- List of prehistoric mammals
- Mammal classification

External links


- [http://www.nceas.ucsb.edu/~alroy/nafmsd.html North American Fossil Mammal Systematics Database.]
- [http://paleocene-mammals.de/ Paleocene Mammals], a site covering the rise of the mammals
- [http://www.enchantedlearning.com/subjects/mammals/Evolution.shtml Evolution of Mammals], a brief introduction to early mammals
- [http://home.arcor.de/ktdykes/mesomamm.htm The Evolution of Mesozoic Mammals, a Rough Sketch], an informal introduction
- [http://www.carnegiemnh.org/research/news.html Carnegie Museum of Natural History], some discoveries of early mammal fossils
- [http://www.geocities.com/mammal_taxonomy/index.html Mammal Taxonomy], database of mammals of the world, updated each month
- [http://nmnhgoph.si.edu/msw/ Mammal Species of the World], searchable online version of 2nd edition (1993) of Mammal Species of the World zh-min-nan:Chhī-leng tōng-bu̍t ko:포유류 ms:Mamalia ja:哺乳類 simple:Mammal th:สัตว์เลี้ยงลูกด้วยนม



Wing

:For some other uses of the word "wing" please see Wing (disambiguation). Wing (disambiguation).]] Wing (disambiguation) A wing is a surface used to produce an aerodynamic force normal to the direction of motion by travelling in air or another gaseous medium, facilitating flight. It is a specific form of airfoil. The first use of the word was for the foremost limbs of birds, but has been extended to include other animal limbs and man-made devices. A wing is an extremely efficient device for generating lift. Its aerodynamic quality, expressed as a Lift-to-drag ratio, can be up to 60 on some gliders and even more. This means that a significantly smaller thrust force can be applied to propel the wing through the air in order to obtain a specified lift.

Use

The most common use of wings is to fly by deflecting air downwards to produce lift, but upside-down wings are also commonly used as a way to produce downforce and hold objects to the ground (for example racing cars). A sailing boat moves by using its sails as wings to produce lift (in the horizontal plane) from the force of the wind.

Artificial wings

Terms used to describe aeroplane wings

Image:Aircraft wing flaps small dsc06830.jpg|Flaps partially deployed Image:Aircraft wing flaps full dsc06835.jpg|Full flaps Image:Aircraft wing flaps full airbrakes dsc06838.jpg|Full flaps, with airbrakes and spoilers deployed for ground braking
- Leading edge: the front edge of the wing
- Trailing edge: the back edge of the wing
- Span: distance from wing tip to wing tip
- Chord: distance from wing leading edge to wing trailing edge, usually measured parallel to the long axis of the fuselage
- Aspect ratio: ratio of span to standard mean chord
- Aerofoil (or Airfoil in US English): the shape of the top and bottom surfaces when viewed as cross sections cut from leading edge to trailing edge.
- Sweep angle: the angle between the perpendicular to the design centreline of the wing in the wing plane, and either the leading edge or 1/4 chord line.
- Twist: gradual change of the airfoil (aerodynamic twist) and/or angle of incidence of the wing cross-sections (geometrical twist) along the span.

Design features

Aeroplane wings may feature some of the following:
- A rounded (rarely sharp) leading edge cross-section
- A sharp trailing edge cross-section
- Leading-edge devices such as slats, slots, or extensions
- Trailing-edge devices such as flaps
- Ailerons (usually near the wingtips) to provide roll control
- Spoilers on the upper surface to disrupt lift and additional roll control
- Vortex generators to help prevent flow separation
- Wing fences to keep flow attached to the wing
- Dihedral, or a positive wing angle to the horizontal. This gives inherent stability in roll. Anhedral, or a negative wing angle to the horizontal, has a destabilising effect
- Folding wings allow more aircarft to be carried in the confined space of the hangar of an aircraft carrier.

Wing types


- Swept wings are wings that are bent back at some angle, instead of sticking straight out from the fuselage.
- Forward-swept wings are high performance wings that are bent forward, the reverse of a traditional swept wing. Forward swept wings are also used in some two seat gliders.
- Elliptical wings (technically wings with an elliptical lift distribution) are theoretically optimum for efficiency at subsonic speeds.
- Delta wings have reasonable performance at subsonic and supersonic speeds and are good at high angles of attack.
- Waveriders are efficient supersonic wings that take advantage of shock waves.
- Rogallo wings are two hollow half-cones of fabric, one of the simplest wings to construct.
- Swing-wings (or variable geometry wings) are able to move in flight to give the benefits of dihedral and delta wing. Although they were originally proposed by German aerodynamicists during the 1940s, they are currently only found on some military aircraft such as the Grumman F-14, Panavia Tornado, General Dynamics F-111, B-1 Lancer, Tupolev Tu-160, MiG-23 and Sukhoi Su-24.
- Ring wings are optimally loaded closed lifting surfaces with higher aerodynamic efficiency than planar wings having the same aspect-ratios. Other non planar wing systems display an aerodynamic efficiency intermediate between ring wings and planar wings. Ring wing

Science of wings

The science behind how wings work can be complex and is one of the principal applications of the science of aerodynamics. However at the simplest level, both the upper and lower surfaces of a wing produces lift by deflecting air downward, which propels the flying body upward with an equal and opposite force (see Newton's Third Law). The air is deflected downwards because of Bernoulli's principle. This relates the pressure of air to its local velocity. If the velocity of the air changes as it flows around an object, such as a wing, the pressure of the air also changes. The shape and the angle of attack of the wing causes the air to flow faster above the wing than below, and so the pressure above the wing is less than below the wing. This pressure difference causes a force, called lift that acts at right angles to the air-flow. The science of wings applies in other areas beyond conventional fixed-wing aircraft, including:
- Helicopters which use a rotating wing with a variable pitch or angle to provide a directional force
- The space shuttle which uses its wings only for lift during its descent
- Formula One cars which use upside-down wings to give cars greater adhesion at high speeds
- Sailing boats which use sails as vertical wings with variable fullness and direction to move across water. Structures with the same purpose as wings, but designed to operate in liquid media, are generally called fins or hydroplanes, with hydrodynamics as the governing science. Applications arise in craft such as hydrofoils and submarines. Interestingly sailing boats use both fins and wings.

Evolution of wings in animals

Biologists believe that animal wings evolved at least four separate times, an example of convergent evolution. Insect wings are believed to have evolved about 300 million years ago, pterosaur wings about 225 million years ago, bird wings about 150 million years ago, and bat wings about 55 million years ago. Wings in these groups are analogous structures because they evolved independently rather than being passed from a common ancestor. See also flight.

External links


- [http://www.av8n.com/how/ An Excellent treatment of why and how wings generate lift]
- [http://www.npr.org/templates/story/story.php?storyId=3875411 Demystifying the Science of Flight] - Audio segment on NPR's Talk of the Nation Science Friday
- [http://www.grc.nasa.gov/WWW/K-12/airplane/short.html NASA's explanations and simulations]
- [http://aerodyn.org/Wings/ Advanced Topics in Aerodynamics] Wings for all speeds
- [http://www.nurseminerva.co.uk/adapt/evolutio.htm Evolution of flight] in animals
- [http://jef.raskincenter.org/published/coanda_effect.html Explanation invoking Coanda Effect] Category:Aerospace engineering Category:Aerodynamics Category:Aircraft components ja:翼

Flying squirrel


Fossil Range: Early Oligocene - Recent See Genera. The Petauristinae (also called Pteromyinae) is a subfamily of squirrel (family Sciuridae). They are usually called flying squirrels. There are 36 species in this subfamily, the largest of which is the Woolly Flying Squirrel (Eupetaurus cinereus). The 2 species of the genus Glaucomys (Glaucomys sabrinus and Glaucomys volans) are native to North America, and it is these that are commonly meant when the name "flying squirrel" is used in English, although the term is frequently also used by Europeans to refer to the Siberian flying squirrel (Pteromys volans). Flying squirrels do not fly in the same sense as birds or bats - they do not employ powered flight. Rather, they glide: once they have launched themselves into the air, they have no means of forward propulsion. They are true gliders: that is, unlike a human-made sailplane, they do not use upcurrents in the air to soar, so they will lose height during a glide. However, they can steer themselves very adroitly while in a glide. They do not steer with their tails, as is commonly but erroneously reported. Steering is accomplished by adjusting tautness of the patagium and positioning of the forelegs. The tail acts as a stabilizer in flight, much like the tail of a kite, and as an adjunct aerofoil when "braking" prior to landing on a tree trunk. The flying squirrel has been kept as a domestic pet since the American colonial era. Noted for their tight bond with their owner, the flying squirrel is a very small, low-maintenance creature. Though their lifespan is only about five years in the wild, flying squirrels often live between 10 and 15 years in captivity. This difference in lifespan is due to the natural calcium deficiency of the flying squirrel. In the wild, the animal does not naturally supplement its diet with calcium and thus develops rickets and dies fairly young. In captivity, a small amount of calcium supplement can be added to their diet, prolonging their life by a factor of between two and three.

Genera

Genera
- Aeretes, 1 species, the Groove-toothed Flying Squirrel, northeast China.
- Aeromys, 2 species, Thailand to Borneo.
- Belomys, 1 species, the Hairy-footed Flying Squirrel, southeast Asia.
- Eupetaurus, 1 species, the Woolly Flying Squirrel, Kashmir; rare.
- Glaucomys (American flying squirrels), 2 species, the Northern Flying Squirrel and the Southern Flying Squirrel, North America.
- Hylopetes, 7 species, southeast Asia.
- Iomys, 1 species, Horsfield's Flying Squirrel, Malaysia and Indonesia.
- Petaurillus (pygmy flying squirrels), 3 species, Borneo and Malaya.
- Petaurista (giant flying squirrels), 5 species, southeast Asia (including the (Japanese Giant Flying Squirrel).
- Petinomys, 9 species, southeast Asia.
- Pteromys, 2 species, Finland to Japan (including the Japanese Dwarf Flying Squirrel).
- Pteromyscus, 1 species, the Smoky Flying Squirrel, southern Thailand to Borneo.
- Trogopterus, 1 species, the Complex-toothed Flying Squirrel, China.

Popular culture reference


- The Rocky and Bullwinkle Show
- Samurai Champloo

See also

The following are sometimes confused with flying squirrels:
- Colugo
- Petauridae
- Anomaluridae - scaly-tailed flying squirrels Similarities between them result from convergent evolution.

External links


- [http://www.glaucomys.org/pics.html Glaucomys.org], general info and pictures
- [http://animaldiversity.ummz.umich.edu/site/accounts/classification/Pteromyinae.html Animal Diversity Web: Pteromyinae], classification
- [http://www.isidore-of-seville.com/flyingsquirrel/ Flying Squirrel Central], a directory to over 150 sites Category:Squirrels ko:날다람쥐류

Phalanger


The Southern Common Cuscus (Phalanger intercastellanus) is also known as Grey Cuscus, Grey Phalanger, and To-ili. Category:Possums Category:Australian animals

Glide

Glide can mean:
- Glide API, a 3D graphics interface
- Glide language, a fictional language from the novel The Maze Game
- Glide, Oregon
- Glide is a musical synthesizer parameter, equivalent to portamento
- Glides are semivowels in linguistics and phonology
- Gliding

Membrane

A membrane is a thin, typically planar structure or material that separates two environments. Because it sits between environments or phases and has a finite volume, it can be referred to as an interphase rather than an interface. Membranes selectively control mass transport between the phases or environments. Biological membranes include:
- Cell membrane and intracellular membranes
- mucous membrane
- S-layer Artificial membranes are used in:
- Reverse osmosis
- Filtration (Microfiltration, Ultrafiltration)
- Pervaporation
- Dialysis
- Electrodialysis
- Emulsion liquid membranes
- Membrane-based solvent extraction
- Membrane reactors
- Gas permeation
- supported liquid membranes Theoretical membranes are used in:
- M-theory (simplified) simple:Membranes

Insectivorous

Any organism with a diet that consists chiefly of insects and similar small creatures is an insectivore. Although individually small, insects exist in enormous numbers and make up a very large part of the animal biomass in almost all non-marine environments. In Queensland pastures, for example, it is normal to have a greater total weight of scarab beetle larvae under the surface than of the beef cattle grazing above it. A great many creatures depend on insects as their primary diet, and many that do not (and are thus not technically insectivores) nevertheless use insects as a protein supplement, particularly when they are breeding. The biological order Insectivora includes a number of mammals which happen to be insectivores, but there is no necessary link. Just as many members of the order known as Carnivora are actually omnivores (and one, the Giant Panda, is a herbivore), several members of the Insectivora do not eat insects. Some examples of insectivores include nightingale, swallow, gambusia (also known as mosquitofish), carp, frog, lizard, bat, and spider. Insects also can be insectivores. Examples would be dragonflies, hornets, ladybugs, and praying mantises. Insectivorous plants also exist, including the Venus flytrap, several species of pitcher plants, butterworts, sundews and kin, bladderworts, the waterwheel plant, and brocchinia bromeliads. They are generally native to poor soils that lack nitrogen, which they obtain by trapping insects.

See also:


- Insectivora Category:Eating behaviors simple:Insectivore

Vertebrate


Conodonta
Hyperoartia
:Petromyzontidae (lampreys)
Pteraspidomorphi (early jawless fish)
Thelodonti
Anaspida
Cephalaspidomorphi (early jawless fish)
:Galeaspida
:Pituriaspida
:Osteostraci
Gnathostomata (jawed vertebrates)
:Placodermi
:Chondrichthyes (cartilaginous fish)
:Acanthodii
:Osteichthyes (bony fish)
::Actinopterygii (ray-finned fish)
::Sarcopterygii (lobe-finned fish)
:::Actinistia (coelacanths)
:::Dipnoi (lungfish)
:::Tetrapoda ::::Amphibia
::::Amniota
:::::Sauropsida/(Reptiles)
::::::Aves (Birds)
:::::Synapsida
::::::Mammalia Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. Vertebrates started to evolve about 530 million years ago during the Cambrian explosion, which is part of the Cambrian period (first known vertebrate is Myllokunmingia). The bones of the spinal column (or vertebral column) are called vertebrae. Vertebrata is the largest subphylum of chordates, and contains most animals with which people are generally familiar (except insects). Fish (including lampreys, but traditionally not hagfish, though this is now disputed), amphibians, reptiles, birds, and mammals (including humans) are vertebrates. Additional characteristics of the subphylum are a muscular system that mostly consists of paired masses, as well as a central nervous system which is partly located inside the backbone. The internal skeleton which defines vertebrates consists of cartilage or bone, or in some cases both. The skeleton provides support to the organism during the period of growth. For this reason vertebrates can achieve larger sizes than invertebrates, and on average vertebrates are in fact larger. The skeleton of most vertebrates, that is excluding the most primitive ones, consists of a skull, the vertebral column and two pairs of limbs. In some forms of vertebrates, one or both of these pairs of limbs may be absent, such as in snakes or whales. These limbs have been lost in the course of evolution. The skull is thought to have facilitated the development of intelligence as it protects vital organs such as the brain, the eyes and the ears. The protection of these organs is also thought to have positively influenced the development of high responsiveness to the environment often found in vertebrates. Both the vertebral column and the limbs support the body of the vertebrate overall. This support facilitates movement. Movement is normally achieved with muscles that are attached directly to the bones or cartilages. The contour of the body of a vertebrate is formed by the muscles. A skin covers the inner parts of a vertebrate's body. The skin sometimes acts as a structure for protective features, such as horny scales or fur. Feathers are also attached to the skin. The trunk of a vertebrate is hollow and houses the internal organs. The heart and the respiratory organs are protected in the trunk. The heart is located behind the gills, or where there are lungs, in between the lungs. The central nervous system of a vertebrate consists of the brain and the spinal cord. Both of these are characterized by being hollow. In lower vertebrates the brain mostly controls the functioning of the sense organs. In higher vertebrates the size of the brain relative to the size of the body is larger. This larger brain enables more intensive exchange of information between the different parts of the brain. The nerves from the spinal cord, which lies behind the brain, extend to the skin, the inner organs and the muscles. Some nerves are directly connected to the brain, linking the brain with the ears and lungs. Vertebrates have been traced back to the ostracoderms of the Silurian Period (444 million to 409 million years ago) and the conodonts, a group of eel-like vertebrates characterized by multiple pairs of bony toothplates. All vertebrates have: the ability to form bones; paired, specialised sensory organs and a brain.

External links


- [http://tolweb.org/tree?group=Amniota&contgroup=Terrestrial_vertebrates Tree of Life]
- [http://reference.allrefer.com/encyclopedia/categories/vertz.html Vertebrate Zoology] Category:Chordates ko:척추동물 ms:Vertebrata ja:脊椎動物 simple:Vertebrate th:สัตว์มีกระดูกสันหลัง

Central America

Commonly, Central America is the region of North America located between the southern border of Mexico and the northwest border of Colombia, in South America. Some geographers classify Central America as a large isthmus, and in this geographic sense it sometimes includes the portion of Mexico east of the Isthmus of Tehuantepec, namely the Mexican states of Chiapas, Tabasco, Campeche, Yucatán and Quintana Roo. However, Central America is much more commonly understood to correspond with the nations between Mexico and Colombia. The UN subregion of Central America includes all mainland states of North America south of the US, including Mexico. US

Countries

In one common definition, Central America consists of the following countries (located between the the northwest border of Colombia and the southern border of Mexico—roughly east to west):
- Panama
- Costa Rica
- Nicaragua
- Honduras
- El Salvador
- Guatemala
- Belize

Geography

Central America thus has an area of about 540,000 km² (208,500 mi²), and a width between the Pacific Ocean and the Caribbean Sea ranging from about 560 km to about 50 km (350 to 30 mi). Caribbean Sea.]] The geology of Central America is active, with volcanic eruptions and earthquakes occurring from time to time. In 1931 and 1972 earthquakes devastated Managua, the capital of Nicaragua. Fertile soils from weathered volcanic lavas have made it possible to sustain dense populations in the agriculturally productive highland areas. The <