what do you think is confusing with this first article?
While the importance of bats cannot be overestimated in terms of the ecology of our planet, these nocturnal, flying mammals also perform a very important service to mankind. One recent estimate puts the economic value of bats at $1 billion worldwide, yet many humans continue to destroy these helpful creatures.
BAT BENEFITS
A study published in September 2015 suggests bats save farmers $1 billion annually, worldwide due to the quantity of insects they eat, notes BBC News. Researchers enclosed corn crops in netting approximately 60 feet high that kept bats out of a certain area of corn while allowing insects into the area. During the day, these nets opened to let birds and foragers in, but the nets closed at night to keep out bats, according to IFL Science.
After collecting data on an increase in the numbers of insects that eat corn crops when bats were excluded, most notably the corn earworm, scientists calculated corn growers acquire $1 billion annually in increased yields when bats are allowed to predate these insects naturally. Corn earworms eat other crops as well, including tomatoes and cotton. The $1 billion figure only takes corn yields into account, so that figure may increase when benefits to other crops care are calculated.
The National Science Foundation estimates bats also save farmers $22.9 billion in pesticides every year. Bats even increase fruit yields by pollinating fruit trees as they chase insects or hang out on trees awaiting a tasty meal.
In addition to being financially beneficial, bats eat many insects that spread diseases that can kill livestock and humans. These flying mammals can literally save human lives simply by following their natural insect-eating habits. Unfortunately, human activities threaten bats on a frequent basis.
THREATS TO BATS
Humans, and human activities, represent major threats to bats. People frequently start fires in caves that kill thousands of bats. White-nose syndrome has killed as many as 80 percent of bats in New England states in North America, and cavers can spread the fungus from cave to cave if they are not very careful, hastening the epidemic. Heat stress in Australia, exacerbated by global warming, recently killed more than 30,000 flying foxes, the world's largest bat species. Wind turbines cause bats to alter migration patterns if they realize they are there, while some of these animals also die when they collide with the blades, says Defenders of Wildlife.
There is hope, however, for a brighter, bat-filled future. As more people become aware of threats to bats, humans can take action. In North America, conservationists urge people to stay out of caves that harbor bats in the hope that white-nose syndrome can be contained. As the world tries seriously to lessen the effects of global warming, cooler temperatures and normal weather patterns can help bats survive and thrive in an increasingly harsh environment.
SCIENTISTS REMAIN HOPEFUL THAT A NEW TREATMENT FOR WHITE-NOSE SYNDROME CAN SAVE MORE BATS FROM THIS DEADLY DISEASE. SEE HOW A BACTERIUM, INTRODUCED INTO A CAVE IN MISSOURI, HAS BEGUN TO SAVE MANY BATS ON THE RAINFOREST SITE TODAY.
Bats provide a service worth an estimated US $1bn (£649m) globally by controlling pests on corn crops, a study has suggested.
Scientists carried out a series of experiments to assess the economic and ecological importance of the nocturnal insect-eating mammals to farmers.
Globally, bat populations are under pressure as a result of habitat loss and the spread of diseases.
The findings appear in the Proceedings of the National Academy of Sciences.
"The results of this study are a testament to the value of ecosystem services," said co-author Josiah Maine from Southern Illinois University.
In North America, many bat populations are under threat from a disease called White-Nose Syndrome. Since 2007, the disease has killed millions of bats and continues to spread.
The US National Wildlife Health Centre estimated that bat populations in the north-east of the country have declined by about 80% since the first reported cases of bat fatalities as a result of the disease.
It added: "The true ecological consequences of large-scale population reductions currently underway among hibernating bats are unknown. However, farmers might feel the impact."
Mr Maine told BBC News that he was interested in finding out how effective bats were in terms of providing a pest control service to farmers growing corn (maize).
The team constructed a number of exclosures (a controlled, open-air experimental area) measuring 20 metres by 20 metres and seven metres high, consisting of netting that was suspended by cables.
"This netting allowed the insects to move freely but prevented bats from foraging in those areas," He explained.
"We were only interested in excluding the bats so we constructed the exclosures so all the netting could be slid to one end so we could open them up during the day to allow birds to forage in the area."
Using the data gathered from the field study and combining with other previously published data, the team was able to extrapolate the findings to a global scale and estimate a monetary value for the ecological service provided by bats in terms of pest control in cornfields.
The team wrote: "We estimate that the suppression of herbivory by insectivorous bats is worth more than US$1bn globally on this crop alone."
Mr Maine told BBC News: "Bear in mind that this figure does not take into account for the impacts of bats on the fungal diseases we found in the corn, or the micro-toxins produced by those fungal species.
"It also does not account for the reduced amount of pesticides used in fields, as bats could be providing an additional valuable service to agriculture by suppressing pest populations below the threshold where pesticides are necessary."
Farmers' friend
According to the IUCN's Bat Specialist Group (BSG), bat species account for one fifth of all terrestrial mammals.
As well as being an important predator of insects, bats are also considered to be key seed dispersers and pollinators for many plants.
Yet, the BSG observed: "They are among the most endangered of the world's creatures, primarily because much of their habitat has been eliminated by human development or because they are persecuted.
"Their loss has serious consequences for the ecosystems to which they belong."
An earlier study, publish in Science in April 2011, warned that the loss of bat species in North America could lead to agricultural losses in the region of US$3.7bn each year.
The authors observed: "Urgent efforts are needed to educate the public and policymakers about the ecological and economic importance of insectivorous bats and to provide practical conservation solutions."
Mr Maine echoed this view: "Bats are maligned in the media and there is a public fear, so if we can demonstrate a valuable, positive impact of bats then it is good for the species and it is good for society.
"What it suggests is that conservation is necessary not just from an ethical stance but from an economic standpoint as well."
For some they’re the thing of nightmares, but for farmers they provide a crucial service in helping keep crops pest-free. Now, researchers have been able to calculate just how valuable bats are, and worked out the monetary benefit that bats provide by snapping up the insects that feast on fields of corn.
“Bats are voracious predators of insects, including many crop pest species,” says Josiah Maine, who coauthored the paper published in the Proceedings of the National Academy of Science. “My hope was that it would give us a much better idea of the ecological and economic impact of bats in agriculture.” Indeed, they’ve estimated that bats contribute a whopping $1 billion globally to the corn industry alone though pest control services.
In order to examine their impact on growing corn, researchers built netted enclosures around the crops, which were 390 square meters (4,200 square feet), to keep the flying mammals out of test plots. During the day, they were open for the birds and other pest-eating animals to forage, but at night the nets were drawn over to keep the bats out, which allowed insects such as the corn earworm to wreak havoc without the risk of predation. The results were then compared with control plots which were not netted, allowing them to assess the effect that the bats had on pest abundance and crop damage.
“The main pest in my system was the corn earworm, a moth whose larvae cause billions of dollars' worth of damage to corn, cotton, tomatoes, and many other crops,” explained Maine. “The larvae feed on corn ears, causing direct damage to yield, but they also can introduce an avenue for infection of the corn ear by fungi, which produce compounds that are toxic to humans and livestock.”
The results showed an incredible 60% more earworm larvae inside the netted enclosures, which led to over 50% more corn kernel damage. In addition to the reduction in insects, they also found another surprising benefit – the ears of corn also had fewer fungal infections. Overall, they were able to estimate that the bats increase the yield of corn by about 1.4%, which doesn’t sound like much until you realize it adds up to over $1 billion worldwide. And that is just looking at one pest affecting one crop. With the earworm also impacting cotton and soybean, bats are thought to provide an even greater service.
This study highlights the impressive and somewhat surprising impact that the often maligned animals provide to the agricultural industry, and makes the massive decline of insect-eating bats across the eastern United States even more worrying. It’s been estimated that bat populations have declined by about 80% in the northeastern U.S. due to the emergence of white-nose syndrome in 2006. Caused by a fungus, the disease can wipe out entire roosts of hibernating bats, and to the concern of many, has rapidly been spreading west.
Scientists carried out a series of experiments to assess the economic and ecological importance of the nocturnal insect-eating mammals to farmers.
Globally, bat populations are under pressure as a result of habitat loss and the spread of diseases.
The findings appear in the Proceedings of the National Academy of Sciences.
"The results of this study are a testament to the value of ecosystem services," said co-author Josiah Maine from Southern Illinois University.
In North America, many bat populations are under threat from a disease called White-Nose Syndrome. Since 2007, the disease has killed millions of bats and continues to spread.
The US National Wildlife Health Centre estimated that bat populations in the north-east of the country have declined by about 80% since the first reported cases of bat fatalities as a result of the disease.
It added: "The true ecological consequences of large-scale population reductions currently underway among hibernating bats are unknown. However, farmers might feel the impact."
Mr Maine told BBC News that he was interested in finding out how effective bats were in terms of providing a pest control service to farmers growing corn (maize).
The team constructed a number of exclosures (a controlled, open-air experimental area) measuring 20 metres by 20 metres and seven metres high, consisting of netting that was suspended by cables.
"This netting allowed the insects to move freely but prevented bats from foraging in those areas," He explained.
"We were only interested in excluding the bats so we constructed the exclosures so all the netting could be slid to one end so we could open them up during the day to allow birds to forage in the area."
Using the data gathered from the field study and combining with other previously published data, the team was able to extrapolate the findings to a global scale and estimate a monetary value for the ecological service provided by bats in terms of pest control in cornfields.
The team wrote: "We estimate that the suppression of herbivory by insectivorous bats is worth more than US$1bn globally on this crop alone."
Mr Maine told BBC News: "Bear in mind that this figure does not take into account for the impacts of bats on the fungal diseases we found in the corn, or the micro-toxins produced by those fungal species.
"It also does not account for the reduced amount of pesticides used in fields, as bats could be providing an additional valuable service to agriculture by suppressing pest populations below the threshold where pesticides are necessary."
Farmers' friend
According to the IUCN's Bat Specialist Group (BSG), bat species account for one fifth of all terrestrial mammals.
As well as being an important predator of insects, bats are also considered to be key seed dispersers and pollinators for many plants.
Yet, the BSG observed: "They are among the most endangered of the world's creatures, primarily because much of their habitat has been eliminated by human development or because they are persecuted.
"Their loss has serious consequences for the ecosystems to which they belong."
An earlier study, publish in Science in April 2011, warned that the loss of bat species in North America could lead to agricultural losses in the region of US$3.7bn each year.
The authors observed: "Urgent efforts are needed to educate the public and policymakers about the ecological and economic importance of insectivorous bats and to provide practical conservation solutions."
Mr Maine echoed this view: "Bats are maligned in the media and there is a public fear, so if we can demonstrate a valuable, positive impact of bats then it is good for the species and it is good for society.
"What it suggests is that conservation is necessary not just from an ethical stance but from an economic standpoint as well."
For some they’re the thing of nightmares, but for farmers they provide a crucial service in helping keep crops pest-free. Now, researchers have been able to calculate just how valuable bats are, and worked out the monetary benefit that bats provide by snapping up the insects that feast on fields of corn.
“Bats are voracious predators of insects, including many crop pest species,” says Josiah Maine, who coauthored the paper published in the Proceedings of the National Academy of Science. “My hope was that it would give us a much better idea of the ecological and economic impact of bats in agriculture.” Indeed, they’ve estimated that bats contribute a whopping $1 billion globally to the corn industry alone though pest control services.
In order to examine their impact on growing corn, researchers built netted enclosures around the crops, which were 390 square meters (4,200 square feet), to keep the flying mammals out of test plots. During the day, they were open for the birds and other pest-eating animals to forage, but at night the nets were drawn over to keep the bats out, which allowed insects such as the corn earworm to wreak havoc without the risk of predation. The results were then compared with control plots which were not netted, allowing them to assess the effect that the bats had on pest abundance and crop damage.
“The main pest in my system was the corn earworm, a moth whose larvae cause billions of dollars' worth of damage to corn, cotton, tomatoes, and many other crops,” explained Maine. “The larvae feed on corn ears, causing direct damage to yield, but they also can introduce an avenue for infection of the corn ear by fungi, which produce compounds that are toxic to humans and livestock.”
The results showed an incredible 60% more earworm larvae inside the netted enclosures, which led to over 50% more corn kernel damage. In addition to the reduction in insects, they also found another surprising benefit – the ears of corn also had fewer fungal infections. Overall, they were able to estimate that the bats increase the yield of corn by about 1.4%, which doesn’t sound like much until you realize it adds up to over $1 billion worldwide. And that is just looking at one pest affecting one crop. With the earworm also impacting cotton and soybean, bats are thought to provide an even greater service.
This study highlights the impressive and somewhat surprising impact that the often maligned animals provide to the agricultural industry, and makes the massive decline of insect-eating bats across the eastern United States even more worrying. It’s been estimated that bat populations have declined by about 80% in the northeastern U.S. due to the emergence of white-nose syndrome in 2006. Caused by a fungus, the disease can wipe out entire roosts of hibernating bats, and to the concern of many, has rapidly been spreading west.
bats in a cave in Trinidad. Credit: Gerry Carter
- ecology.com / bats not just for halloween
- The Night Life: Why We Need Bats All the Time--Not Just on Halloween
A vampire bat. Only three of the more than 1,100 species of bats are vampire bats. Contrary to popular belief, vampire bats are not true vampires because they do not suck blood. Rather, they cut a tiny slit in their prey's skin with their razor-sharp front teeth and lick up the resulting blood. Chemicals in the bat's saliva prevent clotting in order to keep the blood flowing until that bat has consumed its fill, which is generally less than an ounce. These anti-clotting chemicals are currently being researched for possible use as anticoagulants for people who are at high risk for blood clots, such as people who have recently suffered strokes. Credit: Brock Fenton
The sight of bats hanging upside down in creepy caves or fleeing in fluttery flocks from their subterranean haunts at dusk like “bats out of hell” may spook even the most rational, otherwise unflappable observer.
Nevertheless, on every day (and night) but Halloween, these much maligned creatures of the night should be loved, not feared. Why? Because, contrary to popular belief, bats do not attack people; bats do not tangle in people’s hair; and even vampire bats are not true vampires. (Vampire bats lick blood but do not suck blood.)
What’s more, unbeknownst to most people, bats make important contributions to ecology, the economy and even to the search for new technologies.
Important Ecological Roles of Bats
The buds of this flower--a Pseudobombax ellipticum--open explosively at night and are primarily pollinated by bats. Credit: Brock Fenten
Bats, which live on all continents except Antarctica, are essential members of many types of ecosystems, ranging from rain forests to deserts. By fulfilling their ecological roles, bats promote biodiversity and support the health of their ecosystems.
The ecological roles of bats include pollinating and dispersing the seeds of hundreds of species of plants. For example, bats serve as major pollinators of many types of cacti that open their flowers only at night, when bats are active. In addition, bats eat copious quantities of insects and other arthropods. On a typical night, a bat consumes the equivalent of its own body weight in these creatures.
Bats, which live on all continents except Antarctica, are essential members of many types of ecosystems, ranging from rain forests to deserts. By fulfilling their ecological roles, bats promote biodiversity and support the health of their ecosystems.
The ecological roles of bats include pollinating and dispersing the seeds of hundreds of species of plants. For example, bats serve as major pollinators of many types of cacti that open their flowers only at night, when bats are active. In addition, bats eat copious quantities of insects and other arthropods. On a typical night, a bat consumes the equivalent of its own body weight in these creatures.
Economic Value of Bats
As bats fulfill their ecological roles, they provide many economically important services. For example, bats serve as essential pollinators for various types of commercially-valuable crops, including bananas, mangos and guavas. In addition, bats consume many crop-eating insects and thereby reduce farmers’ need for pesticides.
All told, according to a 2011 study published in Science, insect consumption by bats reduces the pesticide bill of the agriculture industry in the United States by roughly $22.9 billion per year on average. Another study, partially funded by the National Science Foundation (NSF), calculated the average annual value of Brazilian free-tailed bats as pest control for cotton production in eight counties of south-central Texas at about $741,000.
Inspiration for High-Tech Innovations
Bats offer much to the field of biomimetics, which is the science of modeling cutting-edge technologies based on natural forms. After all, the development of sonar for ships and ultrasound was partly inspired by bat echolocation. Echolocation is the navigation system used by most bats to find and follow their quick-moving insect prey at night, sometimes via daring aerial dogfights and speedy chases–all without crashing into trees, buildings or other obstructions.
A leaf-nosed bat from the New World. The purpose of the leaf structure on the bat's face is not known for sure, but it may be important for echolocation. Credit: Brock Fenton
Here’s how bat echolocation works: A bat emits a structured high frequency sound, usually beyond the range of human hearing, which bounces off surrounding objects and then returns echoes to the bat. By comparing the delay and structure of the echoes to those of the original sound, a bat can calculate its own distance from the objects and determine size and shape of those objects and thereby construct a three-dimensional map of its environment.
Even though a bat’s brain is only peanut-sized, bat echolocation is so sensitive that a bat flying 25 miles per hour in complete darkness would recognize differences in echo delays of less than a microsecond, allowing the bat to distinguish even a junebug from an underlying leaf, according to Universal Sense: How Hearing Shapes the Mind, which was authored by neuroscientist Seth S. Horowitz, whose earlier work was funded by NSF.
How do bats stay focused on sonar echoes from their target prey without being overwhelmed by the cacophony of echoes from other objects? That question is answered by an NSF video about recent research on bat echolocation.
Another bat trait that provides potential grist for future application is the flying ability of bats, which are the only mammals that can fly on their own power. The aerodynamic repertoire of bats, which includes changing flight direction by turning 180 degrees within just three wing beats while flying at full tilt, would be the envy of any fighter pilot, said Horowitz.
Bats are such nimble flyers because of the dexterity of their wings, which–unlike insect and bird wings–are structured to fold during flight, similar to the way that a human hand folds. Also, their wings are draped by stretchy skin and are powered by special muscles. Ongoing research about the structure of bat wings and the mechanics of bat flight may ultimately lead to the development of technologies that improve the maneuverability of airplanes.
See the wonders of bat flight in a Science Nation video that describes an NSF-funded project.
A New, Fast-Spreading Bat Epidemic
A little brown bat is released by a University of California, Santa Cruz graduate student. There are more than 1,000 bat species with varied wing spans, weights and facial features. Bats account for about 20 percent of all mammalian species. Credit: Kate Langwig
The multi-faceted importance of bats only compounds the tragic dimensions of a new fatal epidemic in bats known as white-nose syndrome. The disease, which is named for a fungal growth around the muzzles, wings and other body parts of hibernating bats, was first discovered in the United States during the winter of 2006-2007 in a popular tourist cave in upstate New York.
Since then, the continually spreading disease, which has reached the central United States and Canada, has killed more than five million bats, including up to 95 percent of some bat species in some locations. Scientists believe that white-nose syndrome–which is currently incurable, untreatable and unstoppable–will inevitably drive some bat species to extinction. The disease is similar to a fungal epidemic that is ravaging frog populations in the United States.
The white-nose fungus causes skin lesions on the wings of hibernating bats, which may damage the animals’ hydration, electrolyte balance, circulation and temperature regulation, ultimately causing death by starvation and dehydration. Behavioral changes in infected bats include a failure to wake normally in response to disturbances and premature emergence from hibernation.
The white-nose fungus is known to have existed in bats in Europe before its arrival in the United States. But, as far as scientists know, the fungus does not kill European bats, possibly because European bats species are genetically protected from the disease. Because the presence of the disease-causing fungus in Europe predates its arrival in the United States, and because the fungus was first found in the United States in a tourist cave, scientists suspect that the disease was imported to the United States from Europe, perhaps on the clothing or equipment of traveling cavers.
Differences in Susceptibility
White-nose syndrome is currently known to affect six North American bat species–two of which are less susceptible to the disease than the four others. With NSF funding, Marm Kilpatrick of the University of California at Santa Cruz, Kate Langwig of the University of California, Santa Cruz and Boston University and their colleagues are currently working to identify the reasons for these differences in susceptibility.
So far, a recent study led by Langwig showed that social behavior may influence mortality rates. Specifically, the study indicates that as the size of infected colonies shrinks because of deaths from white-nose fungus, death rates within colonies of species that hibernate singly tend to stabilize. By contrast, death rates within colonies of species that hibernate in tightly packed groups do not.
Hanging out: Hibernating little brown bats that have white-nose syndrome in a mine in New York. Credit: Kate Langwig
Amazingly, the research also has shown that the little brown bat, a species common in the northeast of North America and widely affected by white-nose syndrome, has been–for unknown reasons–becoming less gregarious, going from a species that tended to hibernate in dense clusters to one that now tends to hibernate singly. By changing their behavior, these bats may be reducing disease transmission within their colonies and thereby saving themselves from extinction. By contrast, the Indiana bat, a gregarious species that is listed as an endangered species, is continuing to hibernate in dense clusters and will therefore probably go extinct.
“Our research gives us an indication of which species face the highest likelihood of extinction, so we can focus management efforts and resources on protecting those species,” said Langwig. For example, the U.S. Fish and Wildlife Service is incorporating Langwig’s study results about little brown bats into ongoing deliberations about whether to classify the species as endangered.
Kilpatrick and Langwig are currently researching other factors, in addition to social behavior, that may influence disease susceptibility. One possibility, Kilpatrick says, is that some bat species are less susceptible to white-nose syndrome because their skin hosts bacterial communities that have anti-fungal properties and so protect them from the white-nose fungus.
In addition, Kilpatrick is currently investigating whether and how particular microclimates in caves and mines used by hibernating bats may be affecting the spread of white-nose syndrome. “Some bat species or some individual bats may prefer to hibernate in caves or mines that are relatively hot or cold, or wet or dry,” Kilpatrick said. “We want to know whether such environmental conditions impact susceptibility to white-nose syndrome.”
Amazingly, the research also has shown that the little brown bat, a species common in the northeast of North America and widely affected by white-nose syndrome, has been–for unknown reasons–becoming less gregarious, going from a species that tended to hibernate in dense clusters to one that now tends to hibernate singly. By changing their behavior, these bats may be reducing disease transmission within their colonies and thereby saving themselves from extinction. By contrast, the Indiana bat, a gregarious species that is listed as an endangered species, is continuing to hibernate in dense clusters and will therefore probably go extinct.
“Our research gives us an indication of which species face the highest likelihood of extinction, so we can focus management efforts and resources on protecting those species,” said Langwig. For example, the U.S. Fish and Wildlife Service is incorporating Langwig’s study results about little brown bats into ongoing deliberations about whether to classify the species as endangered.
Kilpatrick and Langwig are currently researching other factors, in addition to social behavior, that may influence disease susceptibility. One possibility, Kilpatrick says, is that some bat species are less susceptible to white-nose syndrome because their skin hosts bacterial communities that have anti-fungal properties and so protect them from the white-nose fungus.
In addition, Kilpatrick is currently investigating whether and how particular microclimates in caves and mines used by hibernating bats may be affecting the spread of white-nose syndrome. “Some bat species or some individual bats may prefer to hibernate in caves or mines that are relatively hot or cold, or wet or dry,” Kilpatrick said. “We want to know whether such environmental conditions impact susceptibility to white-nose syndrome.”
Impacts of Bat Losses
This bat has a long tongue for nectar feeding. The ears of bats are shaped to maximize detection of sound waves for echolocation. Bats emit sounds for echolocation through their mouths or noses, depending on the species. Credit: Brock Fenton
Other topics that are ripe for research involve the responses of ecosystems to plummeting bat populations. “Insect populations are very variable,” said Langwig. “So in order to identify the impacts of bat declines on insect populations, we would need many years of data on insect populations before the arrival of white-nose syndrome as well as many years of data after its arrival for comparison.” But because white-nose syndrome is so new and has spread so fast, scientists do not yet have enough data to determine how the absence of bats will impact their ecosystems, he said.
Other Threats to Bat Survival Besides White-Nose Syndrome
Other threats to bat survival include the use of pesticides and insecticides, habitat loss and the hunting of bats for bushmeat in some regions. In addition, for reasons that are not fully understood, migrating bats are apparently attracted to wind turbines; large numbers of bats have been killed on wind farms in recent years.
Source: National Science Foundation
The greatest threat to bats is people. Habitat destruction and fear are a lethal combination for bats. In some areas, people have even been known to set fires in caves, killing thousands of roosting bats. Bats are also killed by harmful development projects such as wind turbines that are placed along migratory routes. In addition, an emerging disease called white nose syndrome is killing large numbers of hibernating bats in North America.
Climate change could impact bats as well. Over the past 15 years, 30,000 flying foxes in Australia – the largest bats in the world – have succumbed to heat stress during heat waves that push daytime temperatures above 100 degrees Fahrenheit. For bats that depend on nectar or fruits, changes in plant flowering timing could put them out of sync with their food sources. And it remains an open question as to whether the devastation of white nose syndrome is somehow linked to stress from a changing climate.
Reasons for Hope
Renewable energy, such as wind and solar power, is crucial to the future of our planet. However, ensuring that renewable energy sources, such as wind turbines, cause as little environmental harm as possible is just as important. Some wind farms have proven deadly to bats, which suffer fatalities both from collisions and also from simply passing too close to the blades, where sharp changes in air pressure cause a lung injury called “barotrauma.” For reasons that are unclear to scientists, facilities placed on Appalachian ridge tops have caused particularly high fatality rates, but multiple bat deaths have been reported at other facilities as well.
Defenders and other conservation organizations are working with federal and state agencies to look for places where wind turbines can be set up in safely by avoiding birds and bats.
More on Bats: What Defenders Is Doing to Help Bats »
Size: Bats are divided into two suborders: Megachiroptera, meaning large bat, and Microchiroptera, meaning small bat. The largest bats have a 6 foot wingspan. The bodies of the smallest bats are no more than an inch long.
Lifespan: Most bats live longer than most mammals of their size. The longest known lifespan of a bat in the wild is 30 years for a little brown bat.
Other topics that are ripe for research involve the responses of ecosystems to plummeting bat populations. “Insect populations are very variable,” said Langwig. “So in order to identify the impacts of bat declines on insect populations, we would need many years of data on insect populations before the arrival of white-nose syndrome as well as many years of data after its arrival for comparison.” But because white-nose syndrome is so new and has spread so fast, scientists do not yet have enough data to determine how the absence of bats will impact their ecosystems, he said.
Other Threats to Bat Survival Besides White-Nose Syndrome
Other threats to bat survival include the use of pesticides and insecticides, habitat loss and the hunting of bats for bushmeat in some regions. In addition, for reasons that are not fully understood, migrating bats are apparently attracted to wind turbines; large numbers of bats have been killed on wind farms in recent years.
Source: National Science Foundation
Climate change could impact bats as well. Over the past 15 years, 30,000 flying foxes in Australia – the largest bats in the world – have succumbed to heat stress during heat waves that push daytime temperatures above 100 degrees Fahrenheit. For bats that depend on nectar or fruits, changes in plant flowering timing could put them out of sync with their food sources. And it remains an open question as to whether the devastation of white nose syndrome is somehow linked to stress from a changing climate.
Reasons for Hope
Renewable energy, such as wind and solar power, is crucial to the future of our planet. However, ensuring that renewable energy sources, such as wind turbines, cause as little environmental harm as possible is just as important. Some wind farms have proven deadly to bats, which suffer fatalities both from collisions and also from simply passing too close to the blades, where sharp changes in air pressure cause a lung injury called “barotrauma.” For reasons that are unclear to scientists, facilities placed on Appalachian ridge tops have caused particularly high fatality rates, but multiple bat deaths have been reported at other facilities as well.
Defenders and other conservation organizations are working with federal and state agencies to look for places where wind turbines can be set up in safely by avoiding birds and bats.
More on Bats: What Defenders Is Doing to Help Bats »
Size: Bats are divided into two suborders: Megachiroptera, meaning large bat, and Microchiroptera, meaning small bat. The largest bats have a 6 foot wingspan. The bodies of the smallest bats are no more than an inch long.
Lifespan: Most bats live longer than most mammals of their size. The longest known lifespan of a bat in the wild is 30 years for a little brown bat.
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