Recovery: Bats with Your Tequila

The first bat to be delisted by the Endangered Species Act also performs a vital ecosystem service: helping with a vital ingredient in your margarita.

With the alien fungal disease white-nose syndrome devastating North American bats it’s time for some good news about the order. So consider the U.S. Fish and Wildlife Service’s January 5th proposal to delist the endangered lesser long-nosed bat.

“In 1988 there were thought to be fewer than 1,000 bats at the 14 known roosts range wide,” stated the Service. “There are now an estimated 200,000 bats at 75 roosts.”

That phrasing is a bit misleading. The reason there were thought to be fewer than 1,000 bats in 1988 was because most roosts hadn’t been discovered. Still, the recovery work has been inspiring, the resultant population surge remarkable. As the Service’s Arizona field supervisor, Steve Spangle, puts it: “This has been an international team effort involving citizen scientists in Pima County, tequila producers in Mexico, biologists in both the U.S. and Mexico, non-governmental organizations and federal and state agencies, all pulling together under the organizing banner of the Endangered Species Act.”

The Service has a year to consider public comments and render a decision, but it’s clear that delisting is a done deal. “In my business you’re surprised if you don’t get comments against what you’re doing,” Spangle told me. “I’ve heard none.” This will be the first bat taken off the Endangered Species List.

The Chupacabra Scare

The lesser long-nosed bat is a night-flying nectar feeder, evolved to collect pollen on its hairy, elongated muzzle and distribute it to hundreds of plant species which concurrently evolved to feed this bat and other pollinators.

Lesser long-nosed bat with pollen-covered muzzle. Photo © Marco Tschapka
Lesser long-nosed bat with pollen-covered muzzle. Photo © Marco Tschapka

Lesser long-nosed bats don’t get white-nose syndrome because instead of spending winters in dank hibernacula they migrate between the American Southwest and the tropics of Mexico, pollinating plants and preserving ecosystems along the whole route.

Three factors contributed to the bat’s demise — in order of importance: anti-bat superstitions; clumsy, nonselective vampire-bat control; and habitat destruction.

The Lesser long-nosed bat is an important pollinator of plants in Mexico and the American Southwest. Photo by Bruce D. Taubert, Courtesy of Bat Conservation International
The Lesser long-nosed bat is an important pollinator of plants in Mexico and the American Southwest. Photo by Bruce D. Taubert, Courtesy of Bat Conservation International

“Bat persecution got worse in the early 1990s with the chupacabra scare,” recalled ecologist Dr. Theodore Fleming who wrote the recovery plan for the lesser long-nosed bat.

If you haven’t seen a chupacabra (derived from the Spanish “chupar,” meaning “to suck”), there’s a good reason. A chupacabra is a half-man, half-bat critter said to emerge from dark places (only during times of economic hardship) to exsanguinate goats and sheep. Fleming and his colleagues would find burning tires in caves, a popular prescription because when the smoke cleared the caves were invariably chupacabra-free. Another benefit in the eyes of the public was the elimination of whatever bat species happened to be roosting.

And this from Dr. Merlin Tuttle, founder of Bat Conservation International: “When we did our research at Kino Bay we’d ask people where these bats roosted. They’d tell us: ‘Whatever you do don’t go in there. They urinate, and if it gets in your eyes, you’ll go blind.’ We tried to tell them different …”

A Tequila Toast to Bats

Most lesser long-nosed bats spend their lives in Mexico. There’s even a non-migratory population. Mexico was able to delist the species in 2015 thanks to the heroic efforts of Dr. Rodrigo Medellín and his students at the National Autonomous University of Mexico.

Rodrigo Medellín holding a bat. Photo © Marina Rivero
Rodrigo Medellín holding a bat. Photo © Marina Rivero

“I’ve been working to fix the bad reputation of bats,” he declared. “In ten minutes I turn people around, and they come from enemies of bats to defenders. I tell them how lesser long-nosed bats pollinate plants all over our country, including 180 species of agave.”

Tequila is made from Agave tequilana (blue agave). For up to 14 years a plant will store sugar in order to produce one enormous flower spike; then it dies. So to get maximum sugar, farmers traditionally harvested all their blue agave before it bloomed. The plant reproduces not only from seeds but by sending out shoots that produce exact duplicates of the parent. That’s how fields get repopulated.

“More than 20 years ago I went to the growers and told them they owed this wonderful tequila to the bats because of pollination and the least they could do was give a little back by letting a few agaves flower,” Medellín continued. “They sent me packing, not even a thank you. Then ten years ago I went back and gave them this paper that showed 160 million agaves are clones of only two plants. ‘You are playing with fire,’ I said. ‘Genetic diversity is essentially zero. All it takes is for one disease to hit one plant and all are sick.’

Blue agave farm. Photo © David Suro
Blue agave farm. Photo © David Suro

“‘Very interesting Dr. Medellín. Very nice paper. But don’t call us; we’ll call you.’ So six years ago the disease shows up and hits the agave fields hard. I swear that I did not put it in. Then they came to me, very interested, and said: ‘What was that thing about the bats and disease?’ I made a plan: ‘All you need to do is allow just five percent of your agaves to flower, and in one hectare you will be feeding 90 bats per night.’”

I asked Medellín about the claim of some bat biologists that undiscovered, unvisited roosts at the time of listing rendered endangered status unnecessary.

Photo © David Suro
Photo © David Suro

“I don’t believe that,” he replied. “I was part of those early expeditions with the U.S. Fish and Wildlife Service. We went through the habitat in Mexico looking at historical roosts. And where we were supposed to find thousands of bats we found 100 here, 150 there and so on. And some of the caves were empty. All our monitoring is showing stability and growth. Five years ago my students went to two caves, and came back with reports of lesser long-nosed bats. ‘Hit the books,’ I told them. ‘I’m sorry; you are wrong. There have never been lesser long-nosed bats in those caves.’ So they brought me there; and we had 4,000 in one and 5,000 in another.”

In 2014 Medellín, his university and the nonprofit Tequila Interchange Project (an alliance of bartenders, tequila producers and scientists) introduced “bat-friendly tequila.” Public demand for it is another motivator for growers. On November 30, 2016, 300,000 bottles in five brands hit U.S. and Mexican markets: Tequila Ocho, Tapatio, Siete Leguas, Tesoro de Don Felipe and Siembra Valles Ancestral.

Bats at the Hummingbird Feeder

In the U.S. most lesser long-nosed bat habitat is managed by the Bureau of Land Management, Forest Service, National Park Service and the U.S. Army. Roosts in caves and abandoned mines have been protected from human disturbance with site closures and bat-accessible gates. Habitat restoration in Organ Pipe Cactus National Monument and Coronado National Memorial has included agave and saguaro plantings.

Lesser long-nosed bat at a hummingbird feeder in Tucson. Photos © Dr. Theodore Fleming
Lesser long-nosed bat at a hummingbird feeder in Tucson. Photos © Dr. Theodore Fleming

Citizen science has been instrumental in identifying roosts and monitoring populations. In 2007, following widespread agave failure, people in the Tucson area started noticing lesser long-nosed bats at their hummingbird feeders.

The Town of Marana helped coordinate a project where homeowners could register their hummingbird feeders and fill out data sheets, and it set up a website to download data and share information. The project also allowed managers to identify roosts by capturing bats with mist nets and gluing small transmitters to their backs.

Nectar-feeding lesser long-nosed bats are attracted to a hummingbird feeder during a citizen science bat migration monitoring project in southern Arizona. Photo courtesy of Richard Spitzer
Nectar-feeding lesser long-nosed bats are attracted to a hummingbird feeder during a citizen science bat migration monitoring project in southern Arizona. Photo courtesy of Richard Spitzer

Twenty years ago, under Section 10 of the Endangered Species Act, Arizona’s Pima County signed up for a Habitat Conservation Plan by which, in exchange for protecting roosts and food plants, it was guaranteed immunity from prosecution should any activity result in unintentional “take” of lesser long-nosed bats.

When endangered or threatened protection is removed from a species there’s always the danger that it will be forgotten and face old and new dangers — among the latter, in this case, global warming and the slap-dash proliferation of bat-killing wind turbines in Mexico and the U.S.

I couldn’t find one environmental outfit that didn’t support delisting. But because the Fish and Wildlife Service hasn’t always followed through on post-delisting protocols, each group left me with the same cautionary message. Bat Conservation International’s Dr. Winifred Frick articulated it as well as anyone: “We want to have support for monitoring the species so we can make sure these trends toward recovery and stability will continue.”

Published on - Updated on

Join the Discussion

Join the Discussion

Please note that all comments are moderated and may take some time to appear.

33 comments

  1. Maria Jablonska says:

    We must learn about each specie, respect and coexistence with them so the natural balance on Earth will be restore.

  2. Alice Stack says:

    I forgot to add, that without bats, how would I get my delicious Margaritas. After all, what kind of world would it be without bats and Margaritas.

  3. Alice Stack says:

    This article was so informative and uplifting. I didn’t know bats were pollinators. Bats get a bad rap, but your article sheds important light on the value of bats not only to humans but to other species as well. They are also valuable for their very presence and should be appreciated for the wonderful creatures they are.

  4. Marion Wesoski says:

    Go bats! People really need to be educated about all the good things different species of bats do for our environment, including the ones who keep the mosquito population down.

  5. Richard Henderson says:

    Great article. However, I do have one question about the urine in the eyes comment. If urine can be a vector for histoplasmosis, then could blindness be possible.

    1. Lisa Feldkamp says:

      This from https://nei.nih.gov/health/histoplasmosis/histoplasmosis leads me to believe that while bat droppings are a potential vector for histoplasmosis, urine in the eyes would be unrelated –

      Histoplasmosis is a disease caused when airborne spores of the fungus Histoplasma capsulatum are inhaled into the lungs, the primary infection site. This microscopic fungus, which is found throughout the world in river valleys and soil where bird or bat droppings accumulate, is released into the air when soil is disturbed by plowing fields, sweeping chicken coops, or digging holes.

      Histoplasmosis is often so mild that it produces no apparent symptoms. Any symptoms that might occur are often similar to those from a common cold. In fact, if you had histoplasmosis symptoms, you might dismiss them as those from a cold or flu, since the body’s immune system normally overcomes the infection in a few days without treatment.

      However, histoplasmosis, even mild cases, can later cause a serious eye disease called ocular histoplasmosis syndrome (OHS), a leading cause of vision loss in Americans ages 20 to 40.

      Scientists believe that Histoplasma capsulatum (histo) spores spread from the lungs to the eye, lodging in the choroid, a layer of blood vessels that provides blood and nutrients to the retina. The retina is the light-sensitive layer of tissue that lines the back of the eye. Scientists have not yet been able to detect any trace of the histo fungus in the eyes of patients with ocular histoplasmosis syndrome. Nevertheless, there is good reason to suspect the histo organism as the cause of OHS.

  6. Randy Archambault says:

    Years ago my late husband made me a bat house which placed high up on the house under the eves. We were very disappointed because we watched for years, but never saw any bats. Hornets it took over and we had to take it down. I am still hoping to see bats in my yard at night.

  7. Ann Willette says:

    I love it. I love bats and tequila!!~!!

  8. Janet McCarthy says:

    What a positive, informative and uplifting piece! We love bats and we do enjoy tequila on occasion, but were unaware of the interconnection. Going forward, we will buy only bat-friendly tequila. Kudos and thanks to Professor Medellín for his patient but urgent persistence!

  9. Patricia says:

    I thank God that Bats are recognized as worthwhile creatures I love Bats .

  10. Perry Gaspar says:

    They burned tires in caves to chase away bats. How frigging stupid people can be! The chupacabra description is a new one to me. Cabra is a goat. The chupacabra is part man & goat, not bat.