Media & Education
BATS Magazine

Volume 37, Issue 3, 2018

Of the Land

Agaves and bats of the Borderlands

By Katie Jepson


According to an Aztec legend, humans first learned about the edible properties of the agave from the animal world. And while we don’t know for sure who these altruistic critters may have been, it wouldn’t be a stretch to imagine bats playing a major role. You see, if you’re a lesser long-nosed bat, few things are more satisfying than an energy-rich meal of agave nectar. This is especially the case after a long spring migration up to the Borderlands region of the southwestern United States to give birth to your pup. Think of it as a well-deserved Tequila Sunrise.

BCI is focusing restoration efforts on two agave, Agave parryi and Agave palmeri (pictured).
Both are a good source to nectar-feeding bats. 
Copyright Bill Hatcher

And the agave benefits as well. As it turns out, the lesser long-nosed bat boasts poor table manners. The animal will carry bits of pollen from plant to plant, propagating and diversifying agave lineages, which allows the plants to adapt to pests and pathogens. A genetically healthy stand of agave is, of course, a boon to the humans who utilize the plant for food, drink, fuel and fiber. This complex relationship between plant, animal and human has shaped the landscape for thousands of years, giving the Borderlands its distinctive character and making the region ground zero for both bat and agave conservation.

 

Deep Roots

Prior to the introduction of European crops and livestock, the diet of pre-Columbian people of the American Southwest largely consisted of succulent plants like the agave.

Copyright Bill Hatcher

“There is a strong human connection to the agaves,” says Jesús Garcia, an Education Specialist at the Arizona-Sonora Desert Museum.

Garcia regularly gives demonstrations of how the agaves can be cooked and eaten, based on archeology, agricultural and historical evidence. “It’s an amazing way to revive a tradition. We can bring back to life and celebrate agaves in a way that hasn’t been done in a while.”

But agave was more than just a source of food, it also could be used to provide shelter or as a textile. In southern Arizona, the Hohokam people cultivated agaves, transporting plants from higher elevations to the desert valley floor. Rock piles were constructed to create microclimates around the base of the plants to foster better soil to grow the desert plants, remnants of which still dot the landscape today. In fact, over 550 pre-Columbian agave cultivation sites have been documented in Arizona alone. Prominent researchers, like Wendy Hodgson of Desert Botanical Garden, have discovered that some seemingly wild agave, like Agave parryi, exhibit genetic signatures of prehistoric cultivation, a signpost to the plant’s importance to the indigenous inhabitants of the region. This particular agave species is a favorite of bats and humans, and is used to provide agave-derived beverages like aguamiel, pulque and, of course, mescal.

 

Under Pressure

As resilient and emblematic of the Borderlands as the agave may be, the plant and its ecosystem face significant environmental pressures.

Copyright Bill Hatcher

“Early in the last century, episodic drought and large numbers of livestock undoubtedly reduced agave numbers across the landscape, as the young agave flower stalks are high in moisture and sugars,” explains Dan Taylor, BCI’s Director of Public Lands. “And while agave and range conditions recovered over the ensuing decades, more recent pressures due to development, invasive plants and changing climate have brought new challenges.”

In the United States, housing developments, roadways, construction and other impervious surfaces have replaced historical agave patches. In Mexico, agaves face a similar threat, along with the illegal harvesting of wild agave to produce mescal or similar products.

And this is not good for the lesser long-nosed bat; the Borderlands isn’t just a food stop for traveling bats, it’s the destination.

“While blooming agave and cacti exist across Central and Northern Mexico, a portion of the bat’s population likely became migratory to take advantage of the density of food resources in this region during a critical time of reproduction,” explains Taylor.

In short, less agave in the Borderlands means fewer bats and the decline of a unique ecosystem.

Grassroots Effort

Now, if you want to grow agave in the wild, best talk to Francesca Claverie, the Program and Nursery Manager with Native Plant Materials Program at the Borderlands Restoration Network.

“Something that is really interesting is that with growing agave from seed, we really depend on the bats for pollination,” she says. “Now, we can also take offsets or pups from the wild agave, which are clonal offshoots of the plant, but they don’t produce as many agaves for restoration as seed.”

Volunteers with the Borderlands Restoration Network prepare young agaves for planting. 
Image: Dan Taylor/BCI

The Borderlands Restoration Network grows agaves to be planted across the landscape, or sold as seed or container plants to public, government and private restoration groups. Claverie and her colleagues collect seeds from wild agave, while simultaneously gathering all sorts of vital information like soil type, elevation, GPS coordinates, etc. This is all in an effort to keep the genetic integrity and diversity of the wild populations intact. The high-quality agave seeds are then germinated and kept in a greenhouse until they reach a size that is ready for planting, a process that takes about four or five years.

However, once the agave is in the ground, the work doesn’t stop. All sorts of critters like to eat the young tender flowering shoots of the smaller agaves. The long shallow roots, while essential for erosion control, prove to be easy pickings for critters like the javelina.

“The problem is that they are super-tasty for the javelinas,” remarks Claverie. “They are sometimes the trickiest part.”

One solution is to construct small rock piles and fences around the young agave to deter opportunistic feeders, as well as illegal harvesting.

Last spring, Bat Conservation International set a bold goal of planting 100,000 native agaves where they are needed, utilizing a variety of factors to ensure these plants get to grow all big and tall. Members and supporters responded with the most successful Spring Fundraising Appeal in the organization’s history. Bat Conservation International is now actively working with partners like the Borderlands Restoration Network where volunteers, students and biologists alike participate in planting efforts. And it’s not just bats that rely on the agave. All sorts of pollinators use the agave for nectar sources, including hummingbirds, orioles, tanagers and various insects like bees, wasps and hawk moths. Currently, there are thousands of agave ready for planting this summer and next.

BCI hopes that bolstering wild agave populations in key areas near lesser long-nosed bat maternity roosts and migratory pathways will help ensure the long-term viability of both agave and bat populations. More agave means food for bats and more wild pollination of agave, which helps restore a fractured ecosystem.

 

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