Night Bees: An Introduction to Bat Pollination

By Contributors
Written By Hannah Fuller

This article was written by a guest contributor, Xander Balwit. Read about Xander here.

As an early-riser and morning-lover, I am suspicious of things that go bump in the night. If we are speaking of bats, I am not the only one who feels this way. Whether for their nocturnal lifestyle, affinity for dank caves, erratic flying, or association with vampires, bats are one of the most maligned and misunderstood creatures on Earth. In addition to their creepy reputation, human antipathy towards bats has only been worsened by rampant misconceptions about rabies. While it is true that bats are responsible for the majority of human rabies infections, the numbers are staggeringly low, with only 1-2 people a year in North America dying due to bat-contracted rabies. This means that more people in the US die from falling coconuts and vending machine accidents annually than they do from bat bites, and yet it is bats and not pina coladas that remain unpopular. However, the poor public image of the world’s only flying mammal does nothing to deter the passion of Merlin Tuttle, the world’s foremost expert on bats,  Tuttle studies the enormous role bats play in the overall health of ecosystems, helping to disperse seeds, fertilize soil, control pests, and even pollinate plants, including economically and culturally important crops such as agave and bananas. Tuttle shares that “fortunately, the truth about bats is extremely powerful.” He believes that once people understand all that bats do for the environment and for our food systems, they will become ardent advocates and lovers of bats. 

While the majority of the world’s over 1,300 bat species are insectivorous, over 500 species feed off of the nectar from plants and serve as their pollinators — a process known as chiropterophily. Without the work of these odd little mammals with elongated snouts and tongues up to a third of the length of their bodies, we could not easily enjoy delicacies like tequila, coffee, chocolate, and bananas. Even the plants that bats do not pollinate directly are reliant on bats as a means of pest control. Tuttle says that it is estimated that bats provide 23 billion dollars worth of pest control in the US each year. To satiate the high-caloric needs of their endothermic metabolisms, bats can consume up to 1,200 mosquito-sized insects every night, including insects like potato beetles and corn earworms that are known to wreak havoc on crops. The next time we see bats flying over our gardens, instead of high-tailing it for the house, we should rest assured knowing that they are helping us to keep our cruciferous vegetables pest-free. 

Chiropterophily from Bananas to Tequila

Chiropterophily begins when the flowers on banana plants unfurl at night and lure bats toward their pale centers with an odiferous cocktail both musky and sweet. Bats alight around these blooms and extend their long tongues into the flower’s center to draw out nectar, knocking pollen onto their hairy bodies which they then carry off to other plants, pollinating them in the process. The Cavendish bananas we see in supermarkets today are propagated through cloning, but even these bananas can trace their origins back to their wild, bat-pollinated ancestors in the Old World Tropics. Although cloned Cavendish bananas make up 40% of banana production worldwide, there are still extant species of banana that depend on bat pollination. Before bananas were genetically modified and monocultured to increase their commercial success, there was astounding genetic variability across the species as a result of 50 million years of coevolution between bats and bananas. Today, because Cavendish bananas lack their ancestral heterogeneity, they are especially susceptible to blight because any disease that afflicts them will be reproduced across the entire species. This has led to widespread recognition that the Cavendish is on the brink of extinction. So while further genetic modification is one option that might save the Cavendish, the kind of genetic diversity that is encouraged by chiropterophily might do more to stave off future problems related to monocultural cultivation. To improve our chances of maintaining a future with bananas, it is worth exploring the viability of other banana species, many of which are still reliant on bats. For this to happen, bananas and bats require protection and additional research. 

Patron Saints of Tequila

The lesser-long-nosed bat (Genus Leptonycteris) vies with the infamous “Tequila” worm for the honor of being the coolest animal associated with tequila. Yes, blue agave, the plant responsible for mezcal and tequila is a chiropterophilous plant, and the lesser long-nosed bat helps in the pollination of this species. Tequila is not just culturally significant in Latin America but economically important as well, as it is responsible for profits of up to ~7000 million US dollars each year. The significance of the tequila industry suggests that it is in everyone’s best interest to keep the blue agave and its pollinators happy and protected. However, just like bananas, many major tequila manufacturers rely on the consistency and low cost of cloning to reproduce the agave plants, lopping off the agave flowers, and harvesting the plant before bats can reach them. Like the Cavendish, this method leaves the agave plants vulnerable to disease, insofar as genetic diversity can help buffet plants against blight. It also leaves the bats, who depend on the agave nectar for sustenance, without the food source on which they have traditionally depended. 

Fortunately, there are many people who recognize the importance of protecting traditional practices and pollinators when it comes to the manufacture of agave-derived beverages. There is an effort called the Tequila Interchange Project, whose mission is to advocate for bat-safe and sustainable approaches to cultivating agave and mezcal and tequila distillation. Their website urges farmers in the agave industry to adopt sustainable and bat-friendly methods, writing that “The Bat Friendly Tequila and Mezcal™  Project invites producers to allow a few agave plants to flower. Fields conserving 5% of agaves and allowing them to flower will produce tequila and mezcal that will be labeled bat-friendly.” The Tequila Interchange Project aims to not only educate farmers and producers of agave beverages, but also restaurateurs, bartenders, and the general public so that people can make more sustainable choices when it comes to sourcing their spirits. 

Coffee and Cocoa

Coffee and cocoa are two other heavy-hitting food crops whose cultivation would suffer without bats. While bats do not pollinate these plants directly, they participate in seed dispersal and pest control, which produces numerous benefits including everything from enhancing flavor to keeping the price for these commodities at a reasonable level. When it comes to coffee, researchers have found that bats disperse valuable shade-tree species that allow for the kind of microclimatic stability that coffee plants thrive in. In addition to this, there is evidence that shade-grown coffee has higher sugar and lipid contents which make for a tastier and less acidic roast. Additionally, Cocoa is benefited by bats that feed on the pests that would otherwise attack the plump berries or sensitive leaves of the cocoa tree. Other sumptuous spices, such as vanilla and cardamom, also benefit from the presence of these shade trees. 

Takeaways

In terms of human pleasures, then, the world is a more flavorful place because of bats. These bizarre and unique little creatures with belly buttons and bad reputations, promote healthy ecosystems and pollinate plants that provide some of the world’s most cherished foods and beverages. Like many other pollinators, bats are threatened by habitat loss and climate change, especially as the tropics are disproportionately ravaged by deforestation and environmental change. By educating ourselves and others about bats and the critical role they play in our ecosystems, we can bring attention to efforts surrounding their conservation, research, and protection. We also do ourselves a service when we correct misconceptions about the natural world, such as the fear of bats, which has led to indiscriminate campaigns to kill whole colonies, habitat destruction, and enormous expenditures on needless rabies inoculations. Yet the greatest triumph would be if we could learn to value bats, and all creatures, beyond their utility but as marvels in themselves. 

Sources:

Hannah Fuller
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