Volume 12, Issue 4, Winter 1994

A Binational Partnership to Protect Mexican Free-tailed Bats

The conservation of species that migrate across international borders depends on both countries taking action . . .

The conservation of species that migrate across international borders depends on both countries taking action . . .

MENTION Mexican free-tails (Tadarida brasiliensis) to anyone fortunate enough to see an evening flight of these bats from the Congress Avenue Bridge in Austin or Bracken Cave in Central Texas, and they immediately think in terms of vast numbers of bats filling the night sky. When these colonies and others like them contain millions upon millions of bats, it is difficult for anyone to imagine that free-tails could be in trouble. Yet evidence appears to indicate just that. And while colonies in this country have suffered serious loss from disturbance at their roosts, they face potentially greater problems when they migrate south into Mexico each winter. There, ranchers attempting to solve livestock losses to vampire bats (Desmodus rotundus) routinely destroy any bat cave they can find, regardless of what kind of bats live in it. The result has been a dramatic loss of cave-dwelling bats, especially free-tails.

After BCI brought this alarming news to the attention of the U.S. State Department, Office of Terrestrial Ecology and Conservation, they invited Merlin Tuttle and free-tailed bat expert Gary McCracken to explain the plight, needs, and values of free-tailed bats to officials from key federal agencies [BATS, Fall 1994]. The State Department then requested that the U.S. Embassy in Mexico City facilitate a similar meeting for Mexican government leaders and other natural-resource professionals in Mexico.

This binational meeting was held in late October at the Centro de Ecologia on the campus of the Universidad Nacional Aut6noma de Mexico. Merlin Tuttle and Steve Walker of BCI, Gary McCracken of the University of Tennessee, and Mark Bloschock of the Texas Department of Transportation, attended on behalf of the United States. Mexico was well represented by government officials, biologists, environmental educators, and cave explorers. Rodrigo Medellin, a bat biologist from the Centro de Ecologia, served as the meeting facilitator.

Medellin opened the meeting by emphasizing that both countries must take positive action to protect all migratory bat species between the two countries, not just free-tailed bats. Merlin Tuttle went on to describe the values of these bats to people from both agricultural and economic viewpoints. Free-tails are known to be heavy consumers of agricultural pests. Gary McCracken documented the rapid drop in free-tail populations and pointed out that no real correlation has been found to substantiate claims that declines are primarily attributable to pesticides. His research indicates that destruction of roosting caves are more often responsible. Arnulfo Moreno, a bat biologist from Monterrey, Mexico, then presented a summary of his BCI-funded field study, which substantiate McCracken's findings. Of the 10 most important free-tail overwintering caves in Mexico, over half have lost 95 to 100 percent of their bats. Extensive burning of cave entrances was well documented, some of the caves so badly damaged that they may never be able to house bats again [BATS, Summer 1991].

SINCE THEN, local education initiatives in Mexico have been yielding positive results. Susana Pint, of the ZOTZ Speleological Club in Guadalajara, Jalisco, Mexico, shared highlights of their grassroots educational efforts near important roosting caves. In one instance, local villagers, who had closed the entrance to a cave to prevent bats from entering, were persuaded to reopen it. Using BCI educational materials, Pint convinced them that the bats that roosted there were not vampires and, in fact, were beneficial to local farmers' crops. Bats have since reestablished themselves in the cave. Arnulfo Moreno's own educational efforts in northern Mexico have reached thousands of people and have resulted in the protection of two important free-tailed bat caves [BATS, Winter 1993].

Another recent effort may offer some hope for creating new roost sites where traditional ones have been destroyed. Mark Bloschock, a bridge design engineer with the Texas Department of Transportation, described a cooperative research project with BCI, which is seeking to understand what makes certain Texas bridges so attractive to bats [see "Research Begins on Bat Friendly Bridge Designs," page 181. The research is showing how bridges can be designed to accommodate roosting bats. Gearing up in anticipation of increased transportation between Mexico and the United States as a result of the NAFTA agreement, highways are being widened and new bridges are being built. What we are learning about bridge roosts in Texas could also be applied to Mexico. Bloschock emphasized, however, that the initiative is aimed at supplementing roosting habitats and is not intended to replace cave protection efforts.

The meeting concluded with a discussion of what steps both countries needed to take to prevent further loss of free-tail bat populations. It was agreed that one of the first and most important steps was for education and that it is urgent that the public and governments of both countries be made aware of the issue. Humberto Berlanga, of the Mexican Department of Forestry and Wildlife, pointed out that the initiative fits well within the objectives of existing binational programs, most notably the North American Forestry Commission's Migratory Species Working Group. A specific action plan is being developed to present to U.S. government officials and newly elected Mexican government officials early in 1995.

BCI will continue to facilitate educational efforts by producing Spanish language materials and trying to help Latin American ranchers solve the problem of livestock loss to vampire bats. BCI's latest audiovisual instruction program, Controlling Vampire Bats and Bovine Rabies, is available in both Spanish and English and has received wide acclaim from veterinarians and conservationists throughout Mexico [BATS, Fall 1994]. Los Murcielagos de America Latina, a Spanish-language program that educates the general audience about the values of bats to ecosystems in Latin America, is also available.

This cooperative initiative holds great promise as a model for environmental efforts aimed at keeping ecologically and economically essential species abundant, while still being responsive to local economic and social needs. Its success could determine the future of our free-tailed bats.

Rodrigo Medellin addresses a binational meeting of biologists, educators, and government officials from the United States and Mexico. Participants gathered this October to discuss how to protect bat species that migrate between the two countries.

Even though sights like this can still be seen, Mexican free-tailed bat populations have shown alarming decline over the past 30 years. The binational partnership seeks to prevent further loss.

All articles in this issue:

Sorry, no PDF available.

Stay up to date with BCI

Sign up and receive timely bat updates

BCI relies on the support of our amazing members around the world.

Our mission is to conserve the world’s bats and their ecosystems to ensure a healthy planet.

Please join us or donate so our work can continue.