The sight of bats crossing the nighttime sky, their scalloped wings silhouetted against the moon, used to send people scurrying into their homes. These odd-looking animals were both feared and disliked in most parts of the world. However, many people now welcome bats, knowing that they eat insects and other pests and do not normally pose a threat to humans.
Although for centuries bats were among the least-studied animals on the earth, interest in bats has been growing since the 1970s. Scientists have studied bat physiology and the behavior of different species. New instruments enable people to study bats in the wild, as well as in captivity, and to keep track of their movements, feeding habits, reproductive patterns, and life spans. Researchers have found more ways to locate these creatures who are nocturnal -- that is, active after dark. As a result, we have learned much about bats and their vital contributions to the balance of nature and to the economy.
There are more than 925 different kinds of bats, and they are found all over the world except at the North and South Poles. Bats can survive in cold climates, damp climates, and dry climates, although the largest bat colonies are found in temperate regions. They live on every continent except Antarctica, and on oceanic islands and archipelagoes.
Because bats are mainly tropical animals, species are most numerous around the equator. They are most diverse in South and Central America, where there are about twice as many species of bats as in parts of Africa, Asia, and Australia, which share similar climates.
Of all mammalian species, an astonishingly high proportion -- about 25 percent -- are bats, and in the tropics, bats make up about 50 percent of the mammalian species. On some islands, they are the only native mammals. Worldwide, bats have the second highest number of species, after rodents, the order of animals that includes mice, rats, squirrels, chipmunks, and rabbits.
Bat populations have declined greatly since the 1950s. Numerous species of bats are endangered or threatened, and more than a dozen species may already be extinct. According to the U.S. Fish and Wildlife Service, around 40 to 50 percent of bats in the United States are considered endangered. Six of the forty-five species that live in the continental United States are on the federal list of endangered species. Three more species that live in the state of Hawaii and in U.S. territories are also endangered. Twenty other species are considered at risk.
Indiana bats are one example of an endangered species. Despite their name, these bats live in several different states. They were among the first bats to be placed on the U.S. Fish and Wildlife Service's list of endangered species. At one time millions of Indiana bats inhabited North America. According to an endangered species specialist for the service, they numbered about 800,000 in 1973, but by 1998 the estimated population had declined to some 350,000.
The main threat to bats is the loss of their habitats and food sources due to a growing human population. This results in increased environmental pollution as well as deforestation -- that is, the cutting down of trees -- not only to use as fuel and building materials but also to clear the land for urban, industrial, or agricultural development.
Other human activities, such as pest control programs, cave exploration, and the destruction of old mines result in many bat deaths each year. In some cases, people deliberately kill large groups of bats. They regard these bats as dangerous carriers of disease or as threats to their crops or livestock. Large colonies of bats in caves have been viciously destroyed by vandals armed with sticks, stones, or guns. Bats also die when exposed to unfamiliar predators, which happens, for example, when their habitats are destroyed and they are forced to relocate to new areas.
Around the world, governments, organizations, and individuals are working to save more bat species from extinction. The number of bat conservationists has grown dramatically since the 1970s. People are working in numerous ways to protect bats and their habitats and roosting places. They educate the public about bats and their important roles as pest eaters and propagators of key plants and trees. Conservation organizations help people to safely remove bats from homes and other places where they are not wanted. They promote wooden bat-house kits and urge people to construct these artificial roosting sites to attract bats to their property.
The media are also describing bats in more positive ways. Articles, books, and programs about bats appear regularly. Photographers have captured images that show bats clinging to smiling humans, looking timid, gentle, and likable. Photos taken before the 1980s usually showed bats baring their teeth and appearing to threaten the person behind the camera.
Young people are also much more informed about bats. Nonfiction books and articles give them facts about these fascinating mammals and show them the important roles bats play in the environment. Likewise, some fiction books feature appealing bat characters. An illustrated children's book called Stellaluna, by Janell Cannon, attracted fans of all ages when it was published in 1993. It is a fictitious account of the adventures of a young fruit bat. To go with the book, there is a stuffed bat with wings that velcro together so that Stellaluna can hang upside down. Other toy bats and bat model kits are also being sold for young people.
Through protective laws, public education, and rescue programs. conservationists are making an impact, but many bats are still critically endangered. As people try to save them, they look for ways to balance the needs and wants of growing human populations with the desire to preserve bats and their habitats.
Source: Endangered Animals & Habitats: Bats, Lucent Overview Series. Lucent Books. 2001.