Bats: an important resource

This post contributed by Terence Houston, ESA Science Policy Analyst This week, the Ecological Society of America is holding its 96th Annual Meeting in Austin, Texas.  As over 3,000 ecologists participate in the meeting’s numerous scientific sessions, a highlight in Austin that most meeting attendees will make every effort to see are the city’s famous bats. As seen in the video below, between March and November, every evening around dusk, onlookers near the Ann W. Richards Congress Ave. bridge in Austin are treated to the mass emergence of the Mexican free-tailed bat. According to Bat Conservation International, “it is estimated that more than 100,000 people visit the bridge to witness the bat flight, generating ten million dollars in tourism revenue annually.”  People gather on the bridge and on boats to witness the emergence of the bats each evening. Austin’s Congress Ave. bridge contains the largest urban population of bats in the world, around 1.5 million bats. However, in the wild, there are even larger ‘bat communities.’ The densest populations of the Mexican free-tailed bats are found in the Braken Cave of San Antonio, Texas where the bat population can number upwards of 20 million. It’s estimated that colonies that contain multiple millions of bats can consume 250 tons of insects per day. The Mexican free-tailed bat (as known as the Brazilian free-tailed bat) has a wide range from the western United States, through Mexico, Central America and extending through the northern part of South America. They prefer warm climates and migrate to Central America in the winter. The bats have an average lifespan of approximately 18 years. The bats feed primarily on insects, including those which can become crop pests for farmers. The ability of insect-eating bats to consume such mass quantities of pests has made them an invaluable component for both ecosystem and economic health in the areas they inhabit.  For example, researchers in an Ecological Society of America journal article estimated that Brazilian free-tailed bats saved roughly $740,000 in pesticide costs. During a June congressional hearing of the House Natural Resources Subcommittee on Fisheries, Subcommittee Chairman John Fleming (R-LA) quoted a Science magazine article placing the value of insect-eating bats to U.S. agriculture being between “$3.7 to 53 billion each year.” Chairman Fleming also noted that “as a doctor, I was interested in learning that some 80 different medicines come from plants that need bats to survive.” The focus of the Congressional hearing was on the impact white-nose syndrome on bat populations as well as the pivotal role insect-eating bats play for the agricultural industry through pollination and pest control. The fungus that causes the disease, Geomyces...

Read More

Protecting the elusive, cave-dwelling troglobites

“Who will speak for the imperiled troglobites? Charismatic megafauna, they are not. Troglobites—not to be confused with troglodytes (cavemen) or trilobites (extinct arthropods)—are neither warm-blooded nor fuzzy. Most are invertebrates, including insects and crustaceans, but there are also troglobitic fish and amphibians—and all are as weird as they are rare.”

Read More