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Start With the Low-Hanging Fruit—Protecting the World’s Endangered Bats

A Mexican long-tongued bat feeding on agave.
A Mexican long-tongued bat feeding on agave. ©USFWS

There are 1,400 species of bats in the world, and they have been around for more than 50 million years, according to nonprofit Bat Conservation International (BCI), an organization dedicated to the conservation and survival of the world’s bats and their habitats. Found across six continents—all except Antarctica—bats are incredibly diverse. They contribute to the health of the planet by eating insect pests, acting as pollinators, and helping with seed dispersal.


But more than 200 species are in trouble—23 species of bats are critically endangered, 85 are endangered, while 113 are vulnerable.


There are many reasons why bat populations are shrinking. Bats in North America—in 35 US states and seven Canadian provinces—have been affected by a fungal pathogen called white-nose syndrome, which has led to millions of mortalities.


Other dangers stem from human activity, such as the destruction of bats’ forest and cave habitats and the proliferation of wind turbines. On the African island of Mauritius, many people believe fruit bats are damaging fruit harvests, and the government has ordered that 10% of the nation’s 80,000 fruit bats be culled every year, even though the species is endangered.


These creatures are also affected by climate change through tropical storms and drought conditions, for example.



Mylea Bayless, chief of strategic partnerships at BCI, is fascinated by bats’ diversity. “Some of them eat insects, some of them eat fruit. There are bats with little suckers on their feet which allow them to hike up the side of leaves. There are bats that eat frogs and fish, and vampire bats are sanguivores, so they rely on blood. When you look at the diversity, they’re just incredibly amazing.”


According to BCI, they range from the bumblebee bat, the smallest bat in the world measuring up to 3 inches in length and weighing in at 0.071 ounces, to the giant golden-crowned flying fox bat, which has a wingspan of 6 feet.




Uniquely, most bat species only give birth to one pup per year on average, which makes them the slowest-reproducing mammal when their size is considered. 


Bayless also says: “Bats are just this anomaly in terms of how long they’re living—some bats might live 40 years, which is crazy for a mammal of 15 grams [0.5 ounces]. So, scientifically, we have a ton to learn from their unique systems. They can also survive when exposed to a variety of viruses.”


They often also use a single roost (where bats live), sometimes for decades or longer.


Environmental Benefit


“In some places, [bats] eat so many insects that it makes an economic difference for our agricultural crops.”


Bats are valuable for the environment, especially when it comes to insect predation. “In some places, they eat so many insects that it makes an economic difference for our agricultural crops,” Bayless explains.

Mexican long-nosed bat drinks nectar
Mexican long-nosed bat drinks nectar from blooming agave flower. ©Horizonline Pictures/Bat Conservation International

In addition, “the pollination services that bats provide in the tropics and the warmer regions of the world also become incredibly important for many of our agricultural varieties that are economically important,” she says.


They are also “re-foresters.” “One of the unique things about bats is that when they’re eating seeds and fruits, they’re able to fly across large open areas at night and deposit those seeds,” claims Bayless.

White-Nose Syndrome


The BCI carries out research into white nose syndrome … [that] threatens to wipe out two endangered species—the gray bat and the Indiana bat—as well as the northern long-eared bat, which is considered threatened.”


The BCI carries out research into white nose syndrome, a devastating disease that is prevalent across the US and Canada. It threatens to wipe out two endangered species—the gray bat and the Indiana bat—as well as the northern long-eared bat, which is considered threatened.

White nose syndrome on a cluster of little brown myotis in Canoe Creek Mine.
White nose syndrome on a cluster of little brown myotis in Canoe Creek Mine. ©Michael Schirmacher/Bat Conservation International

The disease attacks when bats are hibernating (or in torpor), as they shut down all non-essential functions to maintain a low metabolic rate to help them survive over the winter without feeding. While the bat’s immune system is suppressed, the fungus invades its skin tissues, resulting in tissue damage, increased metabolic rate, and water loss.


But there could be a solution. BCI is investigating whether it might be possible to create a “food buffet” as they enter hibernation “so that they can go into hibernation fatter,” states Bayless. “One of the things we’ve noticed is that […] bats that are really fat when they go into hibernation, have a higher rate of survival.”


Is it possible to create artificially or to augment the insect community outside the bats’ hibernacula before they go into hibernation, to promote a feeding frenzy? That is one of the questions being examined.

Wind Turbines


As green energy becomes popular, more and more wind farms are being developed. But they create problems for bats, particularly North America’s hoary bats.

During migration, they are attracted to the wind turbines and are struck by the spinning blades. Dr. Winifred Frick, BCI’s chief scientist, has claimed that without interventions, this species could decline by 50% by 2028. A paper on fatalities at wind turbines, to which Frick was a contributor, points to estimates that more than 500,000 bats could be killed by wind turbines every year across Canada and the US.

A bat killed by a wind turbine on Buffalo Mountain in Tennessee.
A bat killed by a wind turbine on Buffalo Mountain in Tennessee. ©Chris M. Morris/Flickr (CC BY 2.0 DEED)

The BCI is working with the wind industry and US and Canadian governments to establish whether minimization measures can protect bats. Bats are most active at lower wind speeds—once the wind speed increases, it’s more difficult for them to fly. This means that “feathering” the blades to prevent them from spinning at lower wind speeds, when not much electricity is being generated, might help. This method has the potential to prevent 50% to 75% of bat mortality. The strategy is already being used, but research continues. [For more information on the effect of wind turbines on birds, see the article “Offshore Wind Energy Faces Headwind—Concern for Effects on Marine Life,” in this issue.]


This means that “feathering” the [wind turbine] blades to prevent them from spinning at lower wind speeds … has the potential to prevent 50% to 75% percent of bat mortality.


Meanwhile, BCI is also involved in collaborative data collection and information sharing to inform decisions on the best way to protect bats—which includes the North American Bat Monitoring Program.



The organization has a number of projects focusing on restoring habitat and protecting endangered species. For example, it works with local people in Mexico to cultivate sugar-rich agave plants across the landscape, which are a critical nectar resource and a key component in the diet of the Mexican long-nosed bat and the lesser long-nosed bat. The bats are the main pollinators of desert plants in Mexico and the southwestern US. Investments are made in community greenhouses, where the agave is grown.

Agave planting.
Agave planting. ©Horizonline Pictures/Bat Conservation International

“We’re providing not only agaves for the bats, but creating a long-term partnership with these people to help us restore the landscape and also provide some economic benefit in terms of plants that they can sell or use for all their own purposes,” says Bayless. Agave is used in drinks and alcoholic beverages like tequila.


BCI is also involved in a partnership in Fiji with the National Trust of Fiji and NatureFiji-MareqetiViti to protect the “only known roosting site” of the endangered Fijian free-tailed bat, Nakanacagi Cave on the island of Vanua Levu. The cave has been disrupted and degraded through practices like tourism, mining, and logging. The program involves acquiring the land and putting in place conservation measures.

Fiji Nakanacagi Cave. ©Bat Conservation International

Fijian free-tailed bat. ©Winifred Frick (CC BY-NC 4.0 DEED)



BCI is a founding partner of Bat Week in the US, Canada, and Mexico, which takes place in the last week of October. A range of activities is organized to inform people about these animals and to encourage people to become involved in conservation.


Also aiming to inspire others to develop a love of bats, BCI has several education initiatives. The Bat Walks program, which involves trained volunteers leading nature walks, is popular. During the walks, bat species are identified and awareness is raised about the threats to their survival.


*Yasmin Prabhudas is a freelance journalist working mainly for non-profit organizations, labor unions, the education sector, and government agencies.


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