Trip to El Pinacate, May 2016

Last May, we visited the biggest maternity roost in The Great Desert of Altar and Pinacate Biosphere Reserve in the State of Sonora, Mexico. Our goal was to monitor the colony of bats that use this cave as a maternity roost and sample a few individuals to study their genetics. This year, our team was quite big as there are so many interesting projects that look at several aspects of the biology of the Tequila bat. We spent 15 days working all night long in the middle of the desert collecting tissue samples, parasites, fresh guano, pollen, taking measurements, and filming. 

A normal working day for us involves getting our equipment ready by 4:30pm, drive across the desert for one hour and hike 40min until we arrive to the cave. We then set up camp, hydrate and rest for a few minutes. Dr. Medellin prepares infrared lamps and video cameras to monitor the emergence of the bats from the cave; the emergence begins around 7:30pm and goes on for about 1.5hrs. Once the females have left the cave, Begoña Iñarritu, who is interested in studying the behaviour of newborns, enters the cave and sets up her filming equipment. In the meantime, the rest of us prepare our equipment and rest for a couple of hours before the females come back from feeding.

At about 1:30 am, females start returning to the cave. Luis Viquez and I are interested in different aspects of the migratory behaviour of the Tequila bats; we have been collecting samples for the last 2 years. We wait for the females to return to the cave as we want to make sure they fed and they are well hydrated. We set up mist nets and capture a few animals; this is when things start getting really busy! We need extra hands to process the samples as many bats get captured in the mist nets in a matter of seconds. 

We collect different samples, for example, I collect blood and tissue samples while Luis sets up individual 'restrooms' for the bats. He needs this fresh guano to study the microbiome of the bats. In the meantime, Abigail Martinez Serena, Ana Soler, and Nora Torres Knoop take parasites and vaginal swabs.

This year, we were lucky enough to have Jens Rydell as our official photographer. He came all the way from Sweden and documented this trip. Jens has perfected his technique to photograph bats in flight and combines it with acoustic recordings to identify species. He was a great team member and taught us a lot about photography and field work!  

Marco Tschapka was another official reporter of this trip. If something funny or embarrassing happened, we could rest assure that Marco was documenting that moment forever. We hope those photographs do not see the light of day anytime soon, or at least before we get our degrees! 

This trip was a success and we had yet another amazing time in the Sonoran desert! Thank you to the other team members who helped us collect samples: Estefania Ramirez, Omar Calva, Salvador Loza, and Anna Vogeler. And special thanks to my funders: The Rufford Foundation, Idea Wild, UNAM and Bristol University. 


A new generation of tequila bats

Baby tequila bats are one of the most adorable babies in the animal kingdom. They are born with very little hair and require nourishment during the first couple of months of their lives. Their loving mothers, give birth to one big pup after 5 months of gestation; newborns weight approximately 25% of their mother's weight!

Carrying such a big baby can become quite difficult, specially when the moms have to run errands. Pups are gather together in giant nurseries where they keep warm and cozy until their mothers return from searching food. 

Sometimes however, the best meal is not very close to the caves where the pups are safely hidden. Females are known to fly over 50km to find the juiciest and sweetest flowers that give them the energy to nourish their pup. 

Female bats have two nipples that produce a very rich milk. Babies grow at an exponential rate as they get ready to fly on their own and migrate for the first time.  They have their first outings attached firmly to their mom and eventually learn which flowers and fruit are safe to eat. 

Inside a baby nursery  

Two pups clinging to each other  

Two pups clinging to each other  

A female looking for her little one amongst hundreds 

A female looking for her little one amongst hundreds 

The importance of bats for pollination

The agaves have evolved two types of reproduction: sexual and asexual. They can sexually reproduce by seeds, and asexually propagate by aerial bulbils and ground-level basal shoots and rhizomes that are genetically identical to the original plant. Both processes may give rise to new individuals, however, it is only through sexual reproduction that the plants are able to exchange genes and increase their diversity to fight detrimental conditions. The fertilization process is achieved via pollination and the main organisms responsible for this are bats!

A lesser long-nosed   bat pollinating an agave flower Photo by Marco Tschapka

A lesser long-nosed bat pollinating an agave flower Photo by Marco Tschapka

Bats ensure the sexual reproduction of the agaves and depend on the nectar for food along their migration. The disruption of this balance has already payed its effects. As agave production has moved to an industrial scale, diseases and pests, particularly by fungi and bacteria have hit the crops causing TMA (tristeza y muerte de agave, "wilting and death of agave"). If bats were allowed to pollinate a small percentage of flowers, this would ensure that key areas for their migration acted as stepping stones while promoting gene flow within the agaves. Having a natural library of genes would allow these plants to defend themselves against diseases and pests.

Efforts to achieve this might be underway with more people interested in consuming a sustainable and 'bat friendly' tequila and mezcal. Together with the Tequila Interchange Project, we are pushing for new reforms that benefit the bats, the plants and the producers. A win - win - win situation!

These drinks are part of our identity that are worth preserving. However, this cannot be done without the conservation of the agaves' main pollinators: the bats! So, next time you have a shot (or better sip it slowly and enjoy!) thank the bats and think what you can do to promote their conservation. And remember: "Para todo mal, Mezcal, y para todo bien, también". "For all evil drink mezcal. And for all good, drink it too".