Chiropterans

Tiamo and Michael H

The mammalian order of //Chiroptera//, (from Greek roots, literally; // cheir //, meaning “hand", and //pteron,// meaning "wing") is more commonly know in the Western world as bats. The members of this order have forearms that form webbed wings, giving the members of this order to capability of flight. However, they do not move their entire forearm in flight, as members of the //Aves//, or birds, must do. They are the only members of the mammalian species capable of flight. Members of the //Chiroptera// species represent about twenty percent of the globes classified mammal species, with 1,240 bat species split into two suborders: Megabats and Microbats.

The Megabat suborder, properly called //Megachiroptera,// largely comprised of frugivores, or fruit eaters. Members of this order are often less specialized for the echolocation that bats are famous for, but have a more advanced sense of smell. The members of this suborder, sometimes contrary to their name, are smaller than the other half of the order. Most fruit bats have large eyes, allowing them to orient themselves visually in the darkness of night and inside dim caves and forests. //Megachiroptera// species are heavily adapted to bite through the skins of fruits, and this mainly is their source of food. These bats aid with the distribution of plants, by spitting or eliminating the seeds from the fruit they consume away from the concentrations of the source. Tests have been conducted to test and see whether these bats are reservoirs, or carriers, of dangerous diseases. Some species of //Megachiroptera// have been tested for the presence of deadly diseases, including Ebola, and finding them present in several species, while the subjects did not exhibit any symptoms or other indicators of infection. For a visual example, see Figure II.

The Microbats constitute the suborder //Microchiroptera// within the order of //Chiroptera//, which’s members mainly feed upon insects, although some of the larger species hunt birds, lizards, frogs or occasionally, on fish. Several other species, however, feed on the blood of large mammals, these hematophagic vampire bats exist in Central America. All members of the species are more advanced means of finding food and navigation than their compatriots in the //Megachiropteran// branch. Members of the Microbats suborder generate an ultrasound frequency from their larynx and emit the sound through the nose or the open mouth. The frequency travels through the organism's environment and bounces around, off of objects and obstacles. Microbats use this as their primary means of navigation, as a sort of primitive radar. these calls range in frequency from 14,000 to over 100,000 Hertz, well beyond the range of the human ear, typically considered to be from 20 Hertz to 20,000 Hertz. The emitted vocalizations form a broad beam of sound that is used to probe the environment. Microbats are mainly insectivorous, meaning they feed upon insects. However, there are some that feed on the blood of large mammals, these hematophagic vampire bats exist in Central America. For a visual example, see Figure III.

The wings of bats are much thinner than those of birds, allowing bats to maneuver more quickly over short distances and with more control than members of the //Aves//. Bats wings are connected to the fingers of the animal, and the wings themselves are fleshy webbing. Thin and nearly see through, one can easily see the bones that make up the support structure of the appendage. The wings are delicate, and thin, ripping easily. However, the tissue of the bat's membrane is able to regrow, often small tears heal quickly. The surface of their wings is equipped with touch-sensitive receptors on small bumps called Merkel cells, which also found on human fingertips. 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, and to fly more efficiently by changing the shape of its wings in response. The ability of flight has given members of the species one of the greatest, if not the greatest, spanning a good majority of the world. See Figure IV for a visual example.

The method in which bats get water in a very time-consuming and inefficient. Their method of skimming the surface of a body of water, and lowering the jaw to drink a single drop of water. Before skimming again to get a second drop of water, and so on, until it’s needs are satisfied. The precision and control during this extremely low level flight is very high, almost never missing or crashing. Specific species, such as the flying fox or fruit bat, gently skim the water's surface, then land nearby to lick water from their chest. See Figure V for a visual example.

There are some much older bats though. Little fossil evidence is available to help map the evolution of bats, since the small, delicate skeletons do not fossilize very well. However, a tooth from South America, carbon-dated to the Late Cretaceous period, resembles that of an early //Microchiropteran// bat. Most of the oldest known, positively identified bat fossils were already very similar to modern microbats. These fossils, //Icaronycteris, Archaeonycteris, Palaeochiropteryx// and //Hassianycteris//, are from the early Eocene period, about 52.5 million years ago. //Archaeopteropus//, formerly classified as the earliest known //Megachiropteran//, is now classified as a //Microchiropteran.// For a visual example, see Figure VI

Bats' dung, or guano, is so rich in nutrients that it is mined from caves, bagged, and used by farmers to fertilize their crops. During the American Civil War, bat guano was used to make gunpowder for soldiers on both sides of the conflict. However, the handling of bat guano carries risk of rabies, a disease that bats sometimes harbor. because of health problems are related to their faecal droppings, bats should be excluded from inhabited parts of houses. The Centers for Disease Control and Prevention provided highly detailed information on all aspects of bat management, including capture, protocols for exposure, and how to humanely bat-proof. In certain countries, such as the United Kingdom, it is illegal to handle bats without a license.

In European cultures, bats have long been associated with witchcraft, black magic and darkness. The witches incorporate bat in their brew in Shakespeare's Macbeth. Because bats are mammals, yet can fly, this gives them status as liminal beings in many cultural traditions. Bats are also symbols of ghosts, death, and disease. Among some Native Americans, such as the Creek, Cherokee and Apache, the bat is a trickster spirit. 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, both villains, such as Dracula, (and pretty much the entire vampire group in general) And heroes, such as Batman. (The only good character in the entire DC universe) An old wives' tale has it that bats will entangle themselves in people's hair. One likely source of this belief is that insect-eating bats seeking prey may dive erratically toward people, who attract mosquitoes and gnats, leading the squeamish to believe the bats are trying to get in their hair.

(Figure I) The worldwide range of the various Chiroptera species (orange)

(Figure II) Spectacled flying fox, Pteropus conspicillatus, a megabat example

(Figure III) Townsend's Big-eared Bat, Corynorhinus townsendii, an example of a microbat

(Figure IV) The wings of bats

(Figure V) A low-level Chiropteran drinking run

(Figure VI) A greater mouse-eared bat, Myotis myotis, skeleton

(Figure VII) The most notable version of bats in fiction (voice of gravel not included)

References:
Bat. (2013, May 30). In // Wikipedia, The Free Encyclopedia //. Retrieved 16:05, May 31, 2013, from [].

// Bats //. (n.d.). Retrieved from http://animal.discovery.com/mammals/bats.htm