The contributions bats make to the quality of life on earth and to the welfare of humans are many. Bats affect our lives in more ways than we realize. Without bats, many of our favorite fruits, vegetables, and nuts might not be available in grocery stores; life preservers and tequila would likely be more costly; and mosquito and insect crop pests would be much more abundant, leading to increased use of pesticides. Bat guano produces some of the richest fertilizers available.
Even in places so hidden from humans that we are rarely aware of them, organisms that depend on bats for their survival are yielding treasures of great benefit to us. New species of bacteria discovered in North American bat caves are now being studied by major corporations for use in chemical waste detoxification, gasohol production, and improved detergents. Still others may soon be used in the production of new antibiotics.
When a colony of cave-dwelling bats is lost, the potential benefits of countless microorganisms and other animals perish with them. Loss of bats may seriously damage entire ecosystems upon which we depend with unpredictable and potentially disastrous consequences.
Bats are among the most intensely feared and relentlessly persecuted animals on earth. Through ignorance, many populations have been needlessly destroyed. Most people know little about bats, often believing popular myths.In North America, nearly 40 percent of all bat species are included on state or federal threatened, endangered, or sensitive species lists or are candidates for listing. Vandalism and repeated disturbance in roosting caves are primary causes for these declines.
Gray bats were among our most abundant bats in the early part of the twentieth century. Now they are endangered. Indiana bats declined by 55 percent in less than ten years and are also listed as endangered. In he early 1960’s, Eagle Creek Cave in Arizona housed the world’s largest known bat colony, approximately 30 million Mexican free-tailed bats. Yet they declined 99.9 percent in only six years. Imagine the local impact of more than a half a million pounds of additional insects left uneaten each summer night. Bats are virtually defenseless, and large colonies make easy targets. A single act of vandalism can kill millions at a time, having a significant impact on the survival of an entire species. Many bats must live in large colonies in order to successfully rear young. Yet most species produce only one young per year. These factors combine to make bats exceptionally vulnerable to extinction.
Bats and Economics
Many of the world’s most economically important plants rely on bats. Some crops from these plants are valued in the hundreds of millions of dollars each year and are crucial to the economies of cash-poor developing countries. Many of our cultivated crop plants still rely on bats for their survival in the wild. These include fruits such as bananas, plantain, breadfruit, avocados, dates, figs, peaches, and mangoes. Other bat-dependent products are cloves, cashers, carob, balsa wood, kapok filler for life preservers (PFDs), and tequila, which comes from agaves century plants). Though most of these plants are now commercially cultivated, wild ancestral stocks remain essential. They are the only source of genetic material for development of disease-resistant strains and for producing new, more productive plants in the future.
In the Sonoran Desert of the Southwestern United States and Mexico, long-nosed bats play a critical role in the lives of several species of agaves and giant cacti. The giant cacti provide food and shelter for countless other animals. The bats that pollinate their flowers and disperse their seeds were recently declared endangered. The relationships between plants and their animal pollinators and seed dispersers are the result of millions of years of evolutionary interplay. If the bat pollinators disappear, these majestic plants and the wildlife that rely on them could be seriously threatened. Loss of plant and animal diversity is one of the most serious long-term global problems we now face.