Mexican Bats Find Cross-Border Benefactors
Monday, October 16, 2006
MEXICO CITY -- Shortly before sundown they make their first foray, cruising up to 5,000 feet aboveground in search of mosquitoes, moths and other tasty treats. A few hours later, they return home to rest and feed their young before heading out again around midnight.
By daybreak, when Mexican free-tailed bats finally return to their cave, named Cueva de la Boca, the colony will have traveled as far as 62 miles and gobbled some 12 tons of bugs out of the skies near the U.S. border. And in cornfields from Texas to Iowa, farmers are giving thanks.
Or at least they should be.
Sure, bats are creepy. They hang upside down, squeal at high decibels and turn up in movies as blood-sucking fiends. Some even spread rabies. But, it turns out, that in the global ecosystem, bats are humanity's allies.
Every night, all night, as humans sleep, the flying mammals work feverishly. They pollinate plants such as the agave, the source of Mexico's iconic tequila. Their excrement, called guano, is a valuable fertilizer. And bats eat up to one-quarter of their body weight in insects every night, making them one of the simplest, safest, most cost-effective forms of pest control available.
Somehow, that message has not reached most people. For decades, intentionally or otherwise, property owners, hikers and sightseers have trampled habitat, dumped garbage and set fires, decimating the bat populations in many parts of the world.
"We scientists missed a chance to give farmers the right information in the right way at the right time," said A. Nelly Correa, a bat expert at the Center for Environmental Quality at the Monterrey Institute of Technology in Mexico. "Most of us were too busy giving the information to our peers in journals and not to the people who could be our partners."
Bat Lovers Take Action
Now, in a unique cross-border alliance, bat lovers have embarked on a multiyear effort to quantify the damage and replenish the bat population of northern Mexico. The project, being spearheaded by the nonprofit Texas-based Bat Conservation International (BCI), includes detailed mapping of hundreds of present and former bat roosts, educational programs for farmers and even purchases of land to protect the most vulnerable colonies.
In late September, armed with BCI data, the Mexican environmental group Pronatura Noreste bought the Cueva de la Boca cave outside Monterrey for about $500,000. It is believed to be the first purchase of a bat cave by Mexican conservationists, said Magdalena Rovalo, a biologist and director of the organization. Access is now limited to researchers, and plans are underway to build an observation tower in the hopes of generating tourism revenue at the cave, which takes its name from the Spanish word for "mouth."
"If we had a healthy population of bats, we would have pest control and healthy crops at no cost to society and no bad effects on health," Correa said. "And it would be a plus for the economy as bats can become a tourist attraction."
Scientists have identified more than 1,000 species of bats worldwide, representing about one-fourth of all mammal types. Latin America is home to 290 species, 140 of them in Mexico, making the region one of the most diverse bat habitats on the globe. Of all those bats, just two species feed on wild bird blood and only one eats cattle blood, said Correa, who tries at every opportunity to disabuse the public of those blood-sucking stereotypes.
"They have given all bats a bad image very unfairly," Correa said. "Bats are really great guys!"