Pollinators icon 2To celebrate pollinator week guest writer and student D. Gasbarrini offers some points on bat pollination!                                        



Bats are interesting and unique animals in many respects, and they lend a helping wing in more ways than we tend to think, including their irreplaceable role as pollinators. Its likely that plant populations, which have both economic and ecological importance, would suffer if nectarivorous bat populations declined. It is incredibly important to protect our bats and their habitats, not only to preserve biodiversity but also to maintain the mutualistic relationships that these important mammals have with many of the plants in their environment.


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Geoffroy’s Tailless Bat (Anoura geoffroyi) covered in pollen
Photo: Michael & Patricia Fogden

So How Does Pollination Work?

Pollination is a process that involves the transfer of pollen between a male stamen and a female pistil within a plant, and is used by many plants to reproduce. The challenging part of this process is that plants are quite literally rooted into the ground. They cant move in order to distribute their pollen, so they have to rely on help from others to reproduce. This is where bats come in. Similar to hummingbirds and bees, bats play a vital role in the pollination of plants, many of which people rely on for their livelihood.


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Lesser long-nosed bat (Leptonycteris yerbabuenae)
Photo: Bruce D. Taubert

Everybody Wins

Of the many ways in which bats are unique to the mammal class, their ability to fly is surely at the top of anyones list. Like birds, bats require an energy-rich diet in order to satisfy their fast metabolism and maintain their ability to fly. Many bat species, including the greater long nosed bat (Leptonycteris nivalis), spear-nosed bat (Phyllostomus discolor), and Pallas’s long-tongued bat (Glossophaga soricina) are nectarivorous, which means they rely on nectar for nourishment. Nectar is a sugary substance produced by plants and is located very close to the pollen-containing stamen. When a bat approaches a plant to collect nectar, it inevitably makes contact with the stamen, and flies away with pollen on its body. This pollen is then transferred to the pistil of the next plant the bat visits as it continues its hunt for nectar This relationship is mutualistic, as bats benefit from the nutritional reward provided by plants in the form of nectar, and plants benefit by having their pollen distributed. Some plants, like four species of Venezuelan columnar cacti (Steno- cereus griseus, Pilosocereus moritzianus, Subpilocereus repandus, and Subpilocereus horrispinus) have evolved to become specialized in size and shape to accommodate bat pollinators, which are the only pollinators that aid in the reproduction of these cacti.


Far Flung Fliers

An added advantage for plants using bats as pollinators is their ability to fly much farther than insects typically can. The farther a pollinator can move, the greater chance it has of encountering another plant to deposit pollen into. As highly mobile mammals capable of flight, pollination across large distances is among the most important of the ecological services provided by bats. The Phyllostomid family of bats are able to transport pollen up to 800m between trees in their native Puerto Rico. Even more impressive, leaf nosed bats (Phyllostomus sp.) in Brazil can move pollen up to 18km between trees!


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Pallas long-tongued nectar bat (Glossophaga soricina)
Photo: Christian Ziegler

Popular Pollination

Bat species aid in the pollination of about 530 species of flowering plants worldwide, many of which are economically and/or ecologically important, especially in the southwestern United States, Mexico, and northern South America. Three bat species within the genus Leptonycteris are among the critical pollinators for blue agave plants (Agave tequilana) in tropical latitudes that are harvested to supply the multimillion dollar tequila industry in Mexico. In fact, the relationship between these bats and agave plants is so intertwined that the bat populations grow and shrink with the success of these plant populations. Other plants that rely on bats as pollinators include eucalyptus, wild and cultivated bananas, and balsa trees (which are used to produce the worlds lightest timber).


Written by D. Gasbarrini