In our continuing series of articles about endangered species, we once again return to the theme of interdependence, ecosystems, and the harmful effects of species loss from human encroachment. Encroachment means going beyond the boundaries of what may be considered another species' habitat or domain. The domain in question can be that of humans as well as of animals (bears wandering into places established by humans for human enjoyment as well as environmental conservation is an example of this sort of dilemma) and it can also encompass cultural practices with regard to certain species that have persisted for hundreds or even thousands of years—practices which are no longer viable because the balance that maintained the dynamic between native human culture and species survival has been thrown off course.
In this article, we consider the social and environmental dynamics of a variety of members of the bat family, and of why the loss of bats would have serious consequences for human health and welfare and for the environment as a whole.
Bats are neither as terrifying as they have been portrayed in western culture (vampyrical "children of the night"), nor are they "cuddly" (little mouse-bears with wings)—so don't bother bats in their caves. At the very least, hundreds of panicky bats flying out of a cave would startle you! Another reason, of course, is that bats need to conserve their energy in order to survive—yes, a little like the legend about Dracula needing his daytime beauty sleep! If you frighten them, they might expend the energy they are saving up for their nighttime hunting expeditions on avoiding you!
And we need bats for seed dispersal, conservation of native vegetation among the trees they help to plant, and the maintenance of cave ecosystems. The entire region of the Southwest United States owes its characteristic cactus population—of vital importance to the continuation of its ecosystem—to pollination and seed dispersion by bats.
Insect-eating bats also provide vital insect control, of enormous importance to the survival of crops. Bananas, plantains, and papayas, staples in many parts of the world, are just some of the crops that could not reach commercial harvest without the help of insect-devouring bats. And it's not just tropical produce that is at risk: The beetles that would consume and destroy up to a billion dollars of cucumber crops each year, as well as potato, corn, cotton, and grain crops, are a favorite food of bats. Other favorite bat meals include the night-flying insects that endanger forests, and the millions of mosquitoes that pose health risks to human populations.
Aside from the loss of habitat as woodlands are cleared and streams are eroded, the pervasive use of pesticides kills off much of the bats' food supply—not enough to really eradicate the threat posed to crops by insects, but certainly enough to create serious reduction in the food supply of the bats. And here a cycle of contradiction begins: The bats consume up to a third of their body weight daily in insects that endanger agriculture. They are essential to the agricultural industry. Yet these very same bats are themselves endangered by the pesticides that they inadvertantly ingest—pesticides used by the agricultural industry.
Bats are poisoned in huge numbers by eating poisoned insects—insects that the bats are actually better able to control than the insecticides that are poisoning the bats and the ecosystem at large, which includes the food that humans ingest. Left to their own, a bat colony of 300,000 can consume up to a billion insects per night. This same colony can produce up to 10,000 tons of bat guano, or droppings, which is an important and highly efficient fertilizer. (Bat guano has been used throughout the centuries as an important ingredient not just of fertilizer but also of gunpowder, and thus played an enormous role in the outcomes of both the War of 1812 and the American Civil War; there was even a plan during World War II to deploy small bomb-carrying bats, but this plan was shelved when the bats flew off course and blew up an American military building.)
Bat lore and legend is almost universal—which is unsurprising if you consider the fact that bats constitute fully one quarter of the Earth's mammals. In China, the South Pacific, some American Indian tribes, parts of West Africa, and even Ancient Greece, the bat is seen as a symbol of good luck and wisdom, and has none of the dark associations found in western traditions, with their emphasis on blood-sucking and vampyrism largely originating in medieval superstitions and myths. One of the most fascinating aspects of bats is the way in which they are a fusion of two species, retaining distinctive aspects of each—it's both bird and mouse—and that makes it important to many ancient cultures as a symbol of balance and of unity, of oneness, against the duality (or "double" nature) of human existence, in which people strive to make themselves whole.
Now, a caveat, or gentle heads-up, about human-bat interaction: Although bats are not aggressive, and will respond to gentle touch much like any other mammal, some of the larger bats that are out there can indeed give you a nasty bite, although the danger of contracting rabies in this way is fairly remote (only .05% of bats carry rabies, but you must seek immediate medical attention if you suspect you have been bitten by a bat). Bats do not fly into people deliberately, but rather through miscalculation while hunting for an insect, though the bat is far more likely to get hurt in a human-bat collision than you are!
And be careful in damp caves, should you go bat viewing. Just as a damp basement in a house can have harmful or dangerous mold spores that humans can inhale, damp caves can also contain risky spores that can make you very sick at some point after exposure. Do not go into a cave on your own, but only in an environment where bat viewing is controlled by people who are familiar with the viewing status and fungal condition of the cave. Only a very few types of bats inhabit houses, but when they do, their guano can cause a type of dust that gets into crevices in floors, walls, and ceilings and can cause allergies or asthma in humans. Erecting bat houses can provide space for bats to make colonies, as they probably don't want to be in your attic any more than you want them there!
For more information on bats go to:
Loudon Wildlife Conservatory, "Building a Bat House":
www.loudounwildlife.org
Kidzone, "To the Bat Cave":
www.kidzone.wsm
Live Science, "Bat Caves Closed to Fight Deadly Fungus Foe":
www.livescience.com
Bat World NOVA:
www.batworld.org
