Increasing Our Understanding of Bats and Their Impact

Bats comprise 20 percent of Earth’s mammal population. As the second most populous species of mammals in the world, they have a profound impact on ecosystems across the globe—including the humans that are a part of them. Yet despite their prevalence, there is still much left to uncover about these fascinating winged little creatures.

By tracking them through an innovative system on the International Space Station (ISS) to small heartbeat monitors, one Southeastern professor is collecting valuable data that will help increase our understanding of the movements of these amazing animals—and their communications, social structures, and physiology. These efforts may contribute to a momentous impact on not only them and their environments, but humans as well.

nature-leaf-wildlife-mammal-fauna-vertebrate-268323-pxhere.comDr. Teague O’Mara, an assistant professor of biological sciences in the College of Science and Technology since the fall of 2019, specializes in integrative biology. Over the past few years, a large part of his research has focused on bat migratory patterns and behavior.

Part of this research has been conducted as part of an ongoing partnership since 2013 with the Max Planck Society, a renowned public German research organization that operates 84 research institutes, primarily in Germany but also across the globe. The Max Planck Society investigates a wide variety of topics, from plasma physics and optics to rust and plant genometrics. Sponsored by the German government and with a guiding principle of “insight before application,” the organization exists to make initial discoveries about the world.

O’Mara works directly with the Max Planck Institute of Animal Behavior—and currently in conjunction with an out-of-this-world research project that will help provide invaluable data on animal movements on Earth.

Icarus, an international collaborative effort led by the Max Plank Institute of Animal Behavior and in conjunction with the Russian space agency Roskosmos and the German Aerospace Center, utilizes an on-board computer and antenna on the outside of the ISS. It was installed during a spacewalk lasting nearly 7 hours and 46 minutes on August 15, 2018, by two Russian cosmonauts. Because of the extensive amount of power required by this type of system, it utilizes all of the ISS’s solar panels. After time spent working out technical issues and testing, Icarus is now fully functioning. Bats, and other animals, are tagged with monitors that keep track of the system on the ISS and transmit signals, allowing O’Mara and his fellow researchers to gain insight into their movements.

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Russian cosmonaut Sergey Prokopyev lays cable for the installation of Icarus on the Zvezda service module of the International Space Station during a 2018 spacewalk. Image by NASA.

O’Mara has been continually tagging bats. He visited Zambia in late November of 2019 to catch and release more with different types of trackers. “Within the next year we’ll start getting really great data about them,” O’Mara said. “We already have some information about these animals, but especially with this new technology should have great data on how these animals are moving over a year or more. It’ll be really nice.”

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To catch fruit bats for tagging, Teague O’Mara (left) and fellow team members shoot a rope over trees to hang a canopy net in tree gaps. Photo by Blair Costelloe.

While bats are at the heart of O’Mara’s interests and research, the knowledge that Icarus will provide extends to other animals. The project works really well for big species, such as elephants, lions, antelopes, and impalas, since larger animals allow for larger tracking devices. But it will also be used to investigate undiscovered migration patterns for smaller species, such as cuckoos that migrate from Europe to Africa and various types of birds that migrate across North America into Central and South America. “We don’t really know where they go,” said O’Mara.

“But one of the great things about this system is it gives us really cheap and detailed individual-level data about animals,” O’Mara continued. “We see flashes of birds when they’re coming in to migrate, for example, but we don’t know much about their individual stories. This will hopefully give us individual-level stories about how animals deal with life as they need to go from one place to the next.”

These individual-level stories are intriguing in their own right, but they can also lead to a greater understanding of their impact on humans and the world around us.

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A GPS tagged straw-colored fruit bat is ready for release at Kasanka National Park, Zambia. 

“If we know what one animal does, we can start scaling it to populations and can actually start understanding what impacts animals have as they move, especially across their migratory patterns,” O’Mara explained.

These impacts can be profound. As bats—which are the only mammal capable of true and sustained flight—move from place to place, they help spread seeds. This is essential for the replenishment of forests, and it also directly brings about a great benefit to humans.

In addition to wild landscapes, bats make important contributions to the urban areas they visit. “They’re spreading lots of seeds,” said O’Mara. “They’re bringing lots of trees up in to the area, which can be cut down for houses, provide lots of food, and even protect the water—they do a lot.”

Ann Froschauer, USFWSSince they feed on insects, bats also provide a great benefit to humans by providing a natural source of pest control. According to O’Mara, Brazilian free-tailed bats, for example, provide $20 million to $40 million worth of pest control for just the cotton and corn crops in the southern United States each year.

Unfortunately, the movement of some bats has been changing.

“What we’re starting to see is that the migration of these animals in a lot of places is starting to go away,” said O’Mara. “As climates change and temperatures start to even out, more places become profitable winter habitats. These bats only eat insects, and we’re beginning to see in some of the caves in Texas, for example, that they just don’t go anywhere because there’s lots of insects for them to eat there. So why would they move on?”

The collapse of such migrations can lead to a lack of forest revitalization and decreased pest control. “Corn crops get destroyed, and insects like mosquitos can go back up,” O’Mara said. “There are lots of things that can happen just from one animal not moving to another spot. It can also mean that forests don’t get regenerated as fast as they might have in the past.”

The data collected through Icarus and the tagging of these little animals will help increase our understanding of what bat colonies do for any given area.

Although Icarus and O’Mara’s research are concerned with obtaining the raw data, the information that is gathered will be immensely valuable for conservation initiatives. “We can hand the data over to someone else and give them ideas of what solutions might actually be there,” said O’Mara.

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Teague O’Mara prepares mist nets to capture bats in a field in Germany. Photo by Christian Ziegler. 

O’Mara is regularly asked for and provides data, which can be used to create actionable plans and educate the public, often by conservation agencies. “We try to give as much data out as possible,” O’Mara stated. “I get asked for information about environmental impact assessments a lot, especially for places where we’ve tracked animals—because all of the movement data we collect tells us how animals use the landscape.”

Some of the organizations that he works with through the Max Planck Society include Bat Conservation International in Texas, Bats Without Borders in Malawi, and Bat Conservation Africa.

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Small solar-powered GPS tags collect the position of bats and then send this information through mobile phone networks to the data repository Movebank.

In addition to O’Mara’s work with Icarus, and the powerful impact that it may be a part of in the coming months and years, there are additional intriguing aspects about these little creatures—the most diverse group of mammals on the planet—that the Southeastern professor studies.

One of these fascinating areas of study regarding bats is the complex relationships and communications that the animals develop with each other, to which their long lifespans contribute. Only 19 species of mammals on Earth live longer than humans for their body size, and 18 of those are bats.

In one location that O’Mara has studied, groups of unrelated females, each with its own dialect of calls, will regularly meet in the same spot at the same time over their 20-year lifespans, migrating from different locations. Not only are they communicating in the dark across huge distances, but their extended lifespans cause them to form sophisticated relationships.

“Humans have a lot of social and cultural support that keeps our lives going for a long time, and bats seem to show similar things too,” commented O’Mara.

nature-3095615In fact, the function of these social relationships in very large colonies is one area in particular that O’Mara would next like to investigate. There are roughly 2 million bats that live in Bracken Cave in Texas and 10 million where he works in Zambia, for example, “and all of these bats live for a long time and come back to the same places over and over—they have to have buddies there,” he said. “There are probably some small social groups that work within these areas, but we don’t actually know what they do. And it’s probably that these social groups are one of the keys to their really long health spans. They almost never get sick. They just keep going forever, and then they disappear. It’s really intriguing to me that we don’t know something so important about them, but it’s probably one of their key aspects.”

An interest in the social structures is also what initially led O’Mara to begin studying bats. His earlier research and Ph.D. focused on primates, particularly lemurs in Madagascar. As he was considering in what direction he should next take his research, he realized that many of the social questions he was interested in with primates also translated well to bats. He then transitioned into working in a bat lab in Panama. “And once I started working on bats I got hooked,” he said.

305349246_c92d90248e_oIt was also in Panama that O’Mara once tracked a group of large bats that somehow found an island of flowering trees, which they would regularly visit on a 20-mile journey from their own island, crossing ocean. “How do you find this? How do you manage to do this?”, O’Mara asked amazed. “That island is in the middle of an industrial banana field—there is nothing good in that place. It’s full of nasty pesticides, there’s no other food for them in there, and they just had to fly across an ocean (which has nothing for them) and this ocean of bananas (which has nothing for them) to find this little flowering island. And they would go there for an hour and then go back home to their cave.

“Every time you do a study like this it’s totally surprising,” he continued. “Somehow there must be some type of cultural transmission. Without tracking these animals we never would have found such unusual behavior.”

But as interesting as this is, O’Mara said that his favorite study has been monitoring a bat’s heartbeat as it went about its night. “I study a lot about physiology, and I use heartbeats to tell me a lot about the way animals use energy and what they are doing. But the coolest thing I’ve ever done is chasing a small bat around in the forests of Panama listening to its heartbeat,” he said. “We attach a lot of emotion to our own hearts and heartbeats. Our heartbeats speed up when we get excited, slow down when we become calm—you can hear that in an animal too.”

O’Mara tagged bats with a small device that recorded and transmitted the sounds of their heartbeats as beeps. Through this he was able to gain insight into the nightly activities of individual bats, from following along with their speeding heartbeats as they felt fear or flew through the night sky to listening to their slowed beeps as they settled down.

This not only created an awe-inspiring feeling from the personal connection, but also led to increased knowledge about the unique mechanisms that these bats use for conserving energy. The lowering of heart rates at regular intervals in order to save energy during the day is one such adaptation.

“Bats have different kinds of social structures and physiology to make sure that they can run their life at the speed of a Ferrari, but then slow it down as well. They can go between these two effortlessly,” said O’Mara. “To me that’s kind of amazing.”

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Teague O’Mara displays the wing of a common noctule bat in Switzerland. Photo by Kamran Safi. 

Uncovering and interpreting such information—from their movements and communications to their social structures and physiology—not only contributes to a greater scientific understanding of bats, but it can also provide a different lens through which we see these amazing animals. We are able to glimpse in them something of our own selves, forging connections between us and these little mammals.

This association, along with the information gathered on the impact that they and their movements have, can help disband ingrained fears and increase our compassion and concern for them—and for the world around us. As the data currently being collected by O’Mara and his colleagues is applied and the resulting conservation efforts embraced, ecosystems, bats, and humans will all benefit.

Bat_cave_in_El_Maviri_Sinaloa_-_MexicoStudents at Southeastern also now have a direct opportunity to relate to and gain a greater understanding of not only bats, but all of the animals in their local natural environment while additionally acquiring hands-on experience. “With the mammalogy class I taught last semester we had a big camera trapping project in North Oak Park, which was super cool because it actually gave us a much better understanding of what mammals are around Southeastern’s campus,” he said.

The diversity rate they found was much higher than had been previously thought. Red foxes, possums, armadillos, bobcats, grey foxes, and coyotes were among the animals his students were able to identify and monitor roaming through the area.

Interestingly, Louisiana as a whole is also actually one of the most diverse states for bats, hosting many as they migrate from the North. Many of these, including the common free-tailed bat, roost in trees or barns and are most easily seen over ponds and lakes, where they can feed on insects and have access to a water source.

P2660441O’Mara, who commented on how much he has enjoyed the enthusiasm and support from both his students and department during this academic year, his first not only at Southeastern but also in Louisiana, has plans to expand student research opportunities in the future. One of these upcoming initiatives will be a tracking project at Turtle Cove that will provide a great way for many students to gain research experience in the field, as well as serve as an interesting long-term study relating to a timely topic—our changing wetlands.

While teaching at Southeastern and engaging the next generation of possible scientists, O’Mara continues to pursue his intriguing research on bats and their relationships with each other and their environments, as well as remaining active with Icarus and collecting the far-reaching raw data that it will provide over the coming months.

By Sheri Gibson

Bonus Clip:
Click here to hang out with Teague O’Mara as he explains how fruit bats are restoring African woodlands in this short Max Planck Society video.

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