Katharine Galloway Garstka

Bats are not the favorite animals of many people, but they are among the most interesting of creatures. Bats are found in almost every country of the world, and San Diego County has its share. Eleven local bats, of eight genera, are on display at the Natural History Museum. They range in size from the California myotis (Myotis californicus) and the western pipistrelle (Pipistrellus hesperus) to the hoary bat (Lasiurus cinereus), but none of these represent extremes in the bat world. The very smallest bat weighs 1/20 of an ounce and has a six-inch wingspan, while the largest of the flying "foxes” (actually fruit bats) weighs two pounds and has a wingspan of four to five feet. 

Bats are members of the order Chiroptera, which is divided into 16 families comprised of nearly 900 species. They are second only to rodents in number and diversity among the mammals. Bats also have the distinction of being the only true flying mammals. "Flying" squirrels and similar air-borne mammals actually only glide. 

Bats have adapted to fill almost every possible niche and to eat an incredible variety of foods. There are species that exist primarily on fish, and others that eat only insects. Some have modified tongues with brush-like tips to obtain flower nectar and pollen and are, in fact, responsible for the pollination of some flowers. Carnivorous bats eat birds, rodents, lizards, frogs and even other bats. Vampire bats in Mexico, South and Central America lap blood from wounds inflicted on cattle, horses and native animals; humans are also sometimes bitten. Vampire bats are a major vector of rabies transmitted to humans and animals - other bats are much less likely to transmit the disease or to attack other animals. 

Bats have fascinated people for centuries, and many cultures have incorporated bats into their religions and legends. Not all the associations are bad ones; a Finnish people, the Votiaks, believed tat bats are the souls of sleeping men. In parts of China bats are even said to bring good luck. The Chinese word for bat is fu, which is also the name of the character meaning "happiness,” and thus the bat has become a symbol for luck, happiness or longevity. In Chinese art the bat is shown head down, as it hangs when at rest. 

A Mohammedan legend says that Christ created bats to fly at sunset so he would know when to break the fast of Ramadan. The Mayas of Central America even had a bat god, Zotz, a powerful being who controlled fire and was ruler of death and darkness. He is shown in art with a leaf-nose, very similar to a large fruit bat, Artibeus, which is common in that area. 

Bats have been used as totems in Australia, and they appear on coats of arms in Great Britain and other European countries. Bats also appear in American Indian stories, often simply as unique animals. 

Medieval Europeans, on the other hand, endowed them with all sorts of terrible characteristics and associated them with devils, witches and darkness. Even the Bible describes bats in less than complimentary terms. And of course everyone knows that bats are the boon companions of witches, and are a savory addition to any large cauldron of spell-casting liquid. Shakespeare’s witches, however, preferred only the "wool of bat" for their concoction. 

Early medicine, too, found a use for bat parts, including bat's blood, bat oil, bat heads, brains and dung. All have been used (with questionable success) to treat rheumatism, tumors, fevers, pains, and failing eyesight. Oddly enough, bats were thought to provide a cure for baldness, as well as being used as a depilatory. Versatile animals, bats. 

In recent years bats have found a place in medical research. Since they can easily be made to hibernate and can survive exposure to extreme temperatures, they make excellent subjects for disease resistance studies. They are also much more sensitive to DDT than most other mammals, and their wings display blood circulation well. In addition, the ability of some species to navigate by echolocation provides a basis for developing aids for blind people. 

Attempts by man to utilize bats have not always been successful. In the early 1900s, Dr. Charles A.R. Campbell of San Antonio, Texas, promoted a series of “municipal bat roosts" - wooden towers for bats to live in. He believed that large numbers of bats, primarily Brazilian free-tailed bats (Tadarida brasiliensis), could be induced to take up residence in the towers. The bats would provide a source of nitrogen-rich fertilizer, or guano, and would also eat mosquitoes, thus solving the local malaria problem. It has been estimated that an average colony of about 100 small insectivorous bats will eat over 25 pounds of insects during a summer. Unfortunately for Dr. Campbell, few bats were interested in living in the towers. As a final indignity, it has also become apparent that while Brazilian free-tailed bats are insectivorous, they eat very few mosquitoes.

Humans have even attempted to use bats to fight wars. During the Civil War, when supplies of all kinds were scarce in the South, bat guano was used as a source for nitrates to make gunpowder. More recently, during World War II, the U.S. armed forces experimented with a squadron of bomb-carrying bats, once more the common Brazilian free-tailed bat. The plan was to equip the bats with tiny incendiary bombs, and then to place them in containers to be dropped by parachute from airplanes. Before landing, the bats would be released from the containers, disperse, and thus cause many small fires. Like other human plans, these weren't perfect. During testing the system sometimes worked - and sometimes didn't.

Security was also a problem. Driving trucks of squealing animals through the Texas countryside did not help keep the secret weapons very secret. The bats themselves weren’t particularly cooperative, as several escaped wearing their bombs, and caused a minor panic. And then, finally, just at the advent of the atomic bomb, the bomber bat plan was abandoned.

Most bats are not generally considered to be endangered, since they rarely come into contact with humans. However, three U.S. bats, the Indiana myotis (Myotis sodalis), the gray myotis (Myotis grisescens), and the Hawaiian hoary bat (Lasiurus cinereus semotus), are endangered according to the latest U.S.D.I. listing. The Red Data Book lists nine endangered, rare or vulnerable species of bats.

The tendency of certain species to hibernate in large congregations makes them particularly vulnerable to destruction. Many bats migrate long distances, while others hibernate in cool caves, where any disturbance affects thousands or hundreds of thousands of bats. Collecting for research is a check on the population, and insecticides pose a danger to bats. Another problem is the extermination of bats in summer colonies in buildings also inhabited by people. These summer colonies are actually "nursery" colonies, consisting almost entirely of females and their babies. Since bats have a relatively long life span, up to twenty years, their reproductive rate is low - generally one infant per year. Thus, wiping out a group of mother and baby bats in an area can have a drastic effect on the total population.

While most humans don't want to live closely with bats, their extermination could result in a greater concentration of insects that eat crops and spread disease. Bats are an integral part of the ecological system, and anything that endangers them endangers all life.