Bats are from the order Chiroptera, which is Greek for "hand wing." There are close to 1,000 different species of bat and they are found all over the earth except in the deep deserts and the arctic poles. Bats make up almost a fourth of all mammal species. Only the order of rodents has more. Bats are broken into two main suborders. Smaller bats are found in suborder, Microchiroptera, larger bats in Megachiroptera. The Megachiroptera consists of just one family which includes flying foxes and other fruit/flower eating species. The Microchiroptera is more diverse and includes some 17 families in all.
Bats are nocturnal mammals. Although sometimes called "flying rats" they are far removed from rodents. A bat's diet varies, depending on its species, but the majority of bats are insectivores. The bat's nightlife gives it two advantages. First, vast quantities of insects fly at night, and there is not much competition for this food source. Second, there are few enemies (with the exception of certain owls and snakes) who have the agility and the nocturnal gifts to be able to pursue and catch a bat at night.
Bats are the only mammals that can truly fly. Other mammals may glide and give the appearance of flight, such as squirrels and lemurs, but only bats possess powered flight and can hover, flap and soar. The majority of a bat's wing is its hand. The finger bones are super-elongated and a double layer of skin stretches over them. The skin membrane extends across the hands and incorporates the arms, legs and tail. In many species, the skin that extends between the tail and the legs (the interfemoral membrane) is used as a basket or pouch to help catch and hold prey while the bat is in flight. Bats do not fly like birds. Their wing power is generated from their shoulders (as opposed to their chest) and, in slow motion, a bat appears to pull itself, or swim, threw the air. This type of flight gives the bat incredible agility. The bat's thumb is the only part of its hand not incorporated in the wing. The thumb is tipped with a strong claw, allowing the bat to climb and cling to things.
The term "blind as a bat," is incorrect. Bats have perfectly acceptable eyesight, but the majority use echolocation while in flight, and hunting. A bat will emit supersonic cries from its mouth or its nose (it’s hard to echolocate from your mouth when it is full of moths). Bats that use nasal echolocation have folds and flaps of skin on their face called "nose leaves." Scientists believe nose leaves help the bat direct its sound, but they aren't entirely sure. Regardless, the nose leaves tend to give the bat a weird, even fearsome, appearance. After the supersonic cry, a bat will listen with its large, extremely sensitive ears for the "echo," of sound reflecting back. The process of echolocation not only tells a bat there is an object out there, but its size, how far away it is, if it is moving and at what speed, and even the objects texture.
Most Flying Foxes and Megabats, (suborder megachiroptera) do not echolocate, they don't need to since their diet is primarily fruit. These bats live in tropical regions and look more like other mammals, particularly foxes and rodents. The largest bat, with a wingspan of 6 feet, is the Bismarck Flying Fox. The smallest bat, the Bumblebee Bat (suborder microchiroptera), is the size of a jellybean and weighs less than a penny. Perhaps the best known bat is the Vampire bat. The Vampire bat was named for the Medieval European legend, not the other way around. Vampire bats don't even live in Europe, but in Central and South America. They do live on the blood of other animals, primarily horses, cattle and deer, but the amount they consume is minimal. It is not the blood-letting that endangers the bat's "host," but the secondary infection and/or parasites that may contaminate the bite area when the bat has gone.
Bats spend their days hanging upside down by their feet, or roosting. They are fastidiously clean and spend a great deal of time grooming. Although some bats are solitary, most bat species are very social and will congregate in large numbers. The story about bats living in caves is true, but bats may also live in barns, attics, under bridges, and in abandoned mines. Some South American bats make their own shelters from palm leaves. Some bats, primarily in warm climates, live in the open, hanging from trees or crevices. Bats live in places that offer protection from weather fluctuations and safety from predators. They also want a secluded place to raise their young. Females generally give birth to just one pup a year. Infant mortality is high, (if a baby bat looses a grip on its mother or roost, it will fall and die) but bats that reach maturity can live 30 years or more.
Bats are extremely beneficial to humans. They eat millions of insects, pollinate produce and flowers, and scatter the seeds of plants. Their poop, or guano, is used as a nitrogen-rich fertilizer. Bat guano also acts as an ecosystem for multitudes of organisms that help detoxify our wastes and create antibiotics. The anti-coagulant properties of Vampire bat saliva are being studied for use in heart patients and stroke victims. For all their helpfulness, bats are still feared and hated by most humans. Although some species of bats thrive in their millions, there are other bat species that are threatened, even endangered. For their size, bats have the slowest reproductive rate of any mammal so their preservation needs to be a priority. To find ways we humans can help bats, visit the "Bat World Sanctuary" and "Bat Conservation International" websites listed below.
Fun Bat Facts
- The largest known colony of bats lives in Bracken Cave in Texas. Biologists estimate more than 20 million Mexican Free-Tail bats call this cave home.
- It seems only the Chinese give the bat the respect and praise it deserves. In China, bats are considered good fortune.
- Scientists have extensively studied how a bat is able to fly as well as echolocate. The government has been interested for military purposes. Other aspects of bat life and society have received little investigation.
- A single Brown Bat can eat 1,000 mosquitoes in one hour.
Defenders of Wildlife
Bats of San Diego County
Bat World Sanctuary
Bat Conservation International
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