Scientists estimate economic value, but they’re priceless
Brazilian free-tailed bats head out from their homes in Texas at sunset to catch insects. Photo by Paul Ryan/USGS
The best insect-control operation in the United States is worth nearly $4 billion a year to farmers, but costs nothing to run. It’s available all across the country, but you won’t find it in the Yellow Pages. It’s highly effective, yet uses no sprays, chemicals or machinery. And this service not only keeps the insect population stable; it also performs other invaluable services to farmers and the crops they tend.
We’re talking about bats.
Forget Count Dracula; bats are our friends. Every night, across the country and around the world, these aerobatic wonders emerge from within caves, under bridges, inside empty buildings to swoop through the skies, catching and eating insects by the millions and billions. A single little brown bat can eat up to 1,000 mosquito-sized insects in a single hour.
They’re a critical link in the balance of nature, ensuring that our food crops are not devastated by insect swarms.
Bats are also major crop pollinators – as important as bees. They’re essential to bananas, avocados, dates, figs, peaches, and many more plants. And just as a condition known as Colony Collapse Disorder is endangering bees, bats are also under serious threat. In their case, the problem is a condition known as white-nose syndrome (WNS) that was first noticed five years ago in northeastern states. WNS, which has now reached deep into western states, too, is a fungus that causes bats to wake up early from hibernation and use up fat reserves and water. Disoriented, they fly around and eventually starve, freeze or die of dehydration.
The little brown bat is most affected by white-nose syndrome
A new study, The Economic Importance of Bats, warns that loss of bats in North America would have catastrophic consequences, and that we all need to know how important they are and what we can do to protect them. Already in the Northeast, bats are down by 70 percent, and one species most affected by white-nose syndrome, the little brown bat, is set to disappear from the Northeast altogether within the next 20 years.
“People often ask why we should care about bats,” said Paul Cryan, a U.S. Geological Survey research scientist and one of the study’s authors. “This analysis suggests that bats are saving us big bucks by gobbling up insects that eat or damage our crops. It is obviously beneficial that insectivorous bats are patrolling the skies at night above our fields and forests – these bats deserve help.”
Another challenge for bats is the growing number of wind turbines. These may be an important new source of energy, but in 2007, Tom Kuntz, one of the authors of the new study, estimated that in the mountainous region of the Mid-Atlantic Highlands alone, up to 111,000 bats will soon be dying each year by flying into wind turbines or from the pressure changes bats experience when flying near the turbine blades as they turn.
A spotted bat in New Mexico. Photo by Paul Cryan/USGS
“We hope that our analysis gets people thinking more about the value of bats and why their conservation is important,” said Gary McCracken, a University of Tennessee professor and co-author of the analysis. “The bottom line is that the natural pest-control services provided by bats save farmers a lot of money.”
Another bottom line is that the demise of the bats will drive farmers to use far greater quantities of pesticides, with all the consequent ripple effects on the plants, on other animals, and on our own health.
So while the new study stresses the economic impact of the decline of bats, with its estimates of the value of their insect control services, the scientists acknowledge that they have taken this approach in order primarily to get the attention of policy makers and the general public.
The value of bats to the whole ecosystem is far greater than what can be given a dollar value. They’re dying off by the millions, yet there’s no way of projecting the true impact of their loss.
What do you say? Have you ever seen a swarm of bats? A bat cave? A bat who’s flown into your home? Are you scared of bats? Let us know with a comment below or on Facebook.
What you can do: Our favorite bat protection organization is Bat Conservation International. You can support their efforts and discover lots of good things to do for bats in your own neighborhood, like installing a bat house. And you can visit some amazing bat viewing sites – some of the best are in Texas.