April 2007, Volume 5, Issue 4

Bats in the News

The Value of Bats


The Economist, the venerable, London-based newspaper with a worldwide circulation, has made a strong pitch for ending the misguided persecution of bats. And it gave a special nod to the economic value of the Mexican free-tailed bats that eat countless insect pests in Texas.

 
“Most of the world’s 1,100 species of bats are benign – helpful, even – to humans and especially to farmers,” the newspaper said.
 
The Economist notes that a study, led by BCI Scientific Advisor Thomas Kunz of Boston University, is being conducted in Texas to quantify the value of those free-tailed bats for Texas farmers.
 
“Each spring, millions of free-tailed bats fly from Latin to Anglo America, [creating] ‘probably the largest aggregation of mammals known anywhere,’ ” Kunz told the newspaper.
 
And every one of those bats, The Economist said, “is worth money to Texas’ farmers. Free-tailed bats feast on masses of moths. Corn earworms (also known as cotton bollworms) are a particular scourge. Their larvae gobble up both crops with alacrity. No precise data are yet available for maize, but early results suggest that each bat near a cotton [field] saves about ten bolls (about two cents’ worth) a night in mid-June. Over many nights and millions of bats, this adds up to a lot of money.”
 
The newspaper cites the agricultural value of bats in other places, as well. Freetails help protect pecan growers in Georgia. Hoary bats feast on leafhoppers, which attack sugarcane in Hawaii. And pallid and big brown bats in California consume moths and beetles that threaten the state’s vineyards and other crops.
 
“Not surprisingly, farmers in all these places have started putting bat houses on their land, while in Texas bridge builders regularly add bat roosts, with properly sized crevices, to woo the creatures,” The Economist said.
 
But it also notes that despite the enormous values of bats, they are still persecuted. In Mexico, for example, indiscriminate efforts to control vampires often “lead to indiscriminate slaughter” of helpful bats.
 
“Perhaps,” the article concludes, “this would stop if another of bats’ benefits to mankind were more widely known. Not all bats are insectivores. Some feed at flowers, and thus act as pollinators. In particular, a Mexican plant called agave is often bat-pollinated. Agave is the principal ingredient of tequila. Without bats, then, Mexico’s national drink would be harder to make – and that would, indeed, be a tragedy.”

All articles in this issue: