Last updated: June 4, 2020
Article
The Bats of Pipestone National Monument
NPS/PISP
Why Are Bats Special?
Bats are mammals (like you and me). This means:
- They are vertebrates (they have backbones)
- They have four limbs
- They give birth to live young (called pups)
- They produce their own milk to feed their pups
- They are warm-blooded (or endothermic) - they produce their own body heat
- They are covered in fur
What makes bats special is that they are the only mammals truly capable of flight. While other “flying” mammals like flying squirrels or lemurs use methods of gliding that resemble flight, bats have specialized wings to power their own flight by flapping. This unique adaptation sets bats apart and allows bats to fill different ecological niches than other mammals.
What Bats Are Found in Pipestone?
We believe eight different species of bats live in Pipestone. They are the:
- Big Brown Bat (Eptesicus fuscus) - Confirmed
- Eastern Red Bat (Lasiurus borealis) - Confirmed
- Hoary Bat (Lasiurus cinereus) - Confirmed
- Little Brown Bat (Myotis lucifugus) - Suspected
- Northern Long-Eared Bat (Myotis septentrionalis) - Suspected
- Silver-Haired Bat (Lasionycteris noctivagans) - Suspected
- Evening Bat (Nycticeius humeralis) - Suspected
- Tricolored Bat (Perimyotis subflavus) - Suspected
Most of the bats that live in Pipestone spend their summers living amongst the trees, either hidden alongside leaves, tucked into hollows, or curled up underneath bark. During the winter, some of these bats will try to find more secure hibernation locations such as caves and mines, while others will migrate to areas of warmer temperatures for the season.
What Conservation Threats Do Bats Face?
Unfortunately, being a bat isn’t all about catching bugs and checking out cool caves. Many of our nation’s bat species are increasingly at risk of severe population loss due to a multitude of threats – many of which are human-caused.
Habitat Loss and Roost Destruction
Around the world, forests are disappearing at an alarming rate due to timber harvesting, agriculture, mining operations, and city development. This destroys important living spaces for many types of bats.
For bats that live in caves, human disturbances create major problems during hibernation. Miners or tourists who visit caves without keeping bat conservation in mind can awaken bats from their deep sleep, causing them to burn through important fat and energy stores that they will need to survive the winter. If the bat uses too much energy, it will wake up too early (before there is enough food to eat) and it will starve to death.
As if that weren’t bad enough, some people intentionally destroy places where bats live, sometimes setting fires to caves and killing entire colonies at a time. Many cultures fear and misjudge bats, and in some countries it is still common to capture or kill bats for meat or for trade.
Climate Change
Climate change is another global issue facing bats (among many other species). In Australia, large bats called flying foxes are experiencing severe stress as temperatures soar above 100°F (38°C) during heat waves. As a result, over 30,000 have died over the past 15 years. For bats that eat fruit or nectar, temperature changes impact the growth of their food sources, meaning bats may show up too early or too late to feed on the plants.
Here in the U.S., extended droughts and wildfires can deplete food sources and destroy bat habitat. Heavy rainfall can kill entire colonies by flooding caves and mines, while severe winter storms can block cave entrances with ice or drop temperatures to dangerous levels while bats hibernate, freezing them to death.
Wind Farms
Wind farms, which on the surface may seem like a good thing, actually present yet another hazard to bats. Although wind energy provides a valuable renewable energy source, we do not yet understand the impacts this technology has on wildlife. Both bats and birds suffer mortalities due to the movement of the turbines’ blades.
The bat species most affected by wind farms are migratory tree-roosting species, such as the hoary bat, the Eastern red bat, and the silver-haired bat. These three species, all local to Pipestone, make up 70-80% of the hundreds of thousands of bat mortalities attributed to wind farms each year. These deaths result not only from collisions with the turbines themselves, but also from changes in air pressure caused by the movement of the blades, which can rupture a bat’s blood vessels and cause lung trauma.
We do not fully understand why bats struggle to navigate around wind farms and avoid impacts with blades. Preliminary studies suggest that slightly increasing the minimum wind speed at which the blades begin to turn may reduce bat mortalities by 50-60%. Ongoing research will hopefully reveal other ways that we can explore sustainable energy without endangering bats and other wildlife.
White Nose Syndrome
Perhaps one of the most devastating threats to bats in America is a deadly disease called White Nose Syndrome (WNS). WNS is caused by a fungus that attacks hibernating bats and gets its name from the white growth that appears around a sleeping bat’s nose. This fungus causes the bats to wake up early and use up their fat reserves, leaving them to starve to death. It is incredibly deadly to species such as the little brown bat, big brown bat, tricolored bat, and Northern long-eared bat (again, all bats that are found in Pipestone). In fact, the Northern long-eared bat is now federally threatened as a result of the impacts of WNS, and scientists believe that by the year 2030, little brown bats, once common throughout the nation, will be reduced to only 1% of their former population. Let that sink in for a moment.
WNS is believed to mostly be spread by bat-to-bat contact and from bats touching areas in cold damp places where the fungus lives. It is likely that humans are also responsible for spreading the disease from cave to cave. The disease was first detected in the United States in New York in 2006, and it was first reported in Minnesota in 2015. Since first detected in Minnesota, some caves have seen population declines as great as 90%, and the fungus continues to spread westward across the country. Just last year (2018) WNS was documented for the first time in our neighboring state of South Dakota. To date, over 5.7 million bats have died nationwide.
Bats Help Us…
What many people do not realize is just how much bats actually help people. Do you like chewing gum? What about mangoes? Bananas? Anybody a fan of tequila? You can thank a bat! All of these foods would not be possible without the help of bats. The plants that produce gum, mangoes, bananas, and agave, as well as plants that provide figs, cashews, avocadoes, peaches – the list goes on! – they are all pollinated by bats!
Just like birds and bees pollinate flowers and help disperse their pollen and seeds, bats do the same. Many plants that bloom at night rely exclusively on bats for pollination. Bats not only help the plants reproduce, but they also increase the genetic diversity of the plants by carrying pollen and seeds long distances.
Bats that eat fruit often play a critical role in re-foresting areas that have been clear-cut. This is especially true in areas where rainforests have been wiped out for agriculture or logging, leaving behind wide, empty spaces. Birds tend to stay amongst trees to avoid predation, and usually drop their feces or poop (which contains seeds from their food sources) directly below their perches, limiting the range of their impact. Bats, on the other hand, do not mind flying across clear openings, and often travel long distances each night. As they fly, they poop, spreading seeds as they go. This has a major impact on initiating new growth in disturbed areas. Some people even call bats “the farmers of the tropics,” because in some areas, up to 95% of new plant growth begins from bat droppings.
Believe it or not, that is not the only benefit of bat poop. Have you ever heard of guano? Guano is another name for bat poop, and it is actually a highly valuable resource because it is a nutrient-rich fertilizer for crops. The next time you add some black pepper to season your meal, keep in mind that 75% of the world’s black pepper is grown in guano! Yum!
That’s all fine and dandy, but most bats here in the United States eat insects, not fruit and nectar, so what good are they? A lot, if you recall how many mosquitoes a single bat can eat in a night! Not only does that mean fewer pesky bug bites for you and me, but worldwide it means less spread of dangerous mosquito-borne diseases like malaria and West Nile Virus.
Even though mosquito control is the most popular reason mentioned in support of bats, it’s important to remember that mosquitos are just little snacks for bats. They would much rather eat a big juicy bug, given the opportunity. Because they fly at night, moths are common targets of bats, and many of these moths are major agricultural pests.
Here in Minnesota, we are smack-dab in the middle of corn country, and it just so happens that one of a local bat’s favorite meals is the corn earworm. This moth’s larvae is responsible for extensive damage to crops including corn, tomatoes, and cotton. A recent scientific study revealed that croplands protected from hungry bats had 60% MORE earworm larvae than croplands where bats were free to hunt. This means that, in the presence of bats, farmers can spend less money on pesticides while still protecting their crops.
Based on this research, scientists determined that bats are worth over $1 billion to the corn industry worldwide. When analyzed with other costs relating to crop damage and pest control, experts estimate that bats save farmers and ranchers across the globe about $23 billion each year! That’s a lot of cash, and those savings pass along to you, the consumer!
As we continue to learn more about bats, we will likely discover even more ways that bats benefit humans. Just over the past several years, scientists discovered that a certain protein found in the saliva of vampire bats acts as an effective anticoagulant, meaning it thins blood and prevents clotting. If you suffer from heart problems or strokes, or knows someone who has, it is possible that this anticoagulant could treat or prevent the problem. This enzyme makes it easier for blood to pump through clogged arteries, and it breaks down blood clots that can cause strokes.
Outside the medical field, bat adaptations also influence wartime technology. During the Civil War, the Confederate Army used bat guano as an ingredient in gunpowder, and prior to World War I and World War II, scientists studied echolocation to improve sonar technology. Even today, you may notice that the thin, flexible wings of some drones mimic bat wings. As we look forward into the future, who knows what new technologies we will model after bats!
What Can We Do To Help Them?
The troubles facing our bat populations seem daunting, but there are a lot of ways that each and every one of us can help make a difference.
Bat boxes are becoming more popular as a way to provide safe, sheltered places for bats to roost and raise their young within our own yards and neighborhoods. Be sure to do some research, though – location can be very important in determining the success or failure of a bat box. You can even tailor your bat box to attract certain species if you wish.
If you already have a bat box, be observant – consider watching the entrance of the bat box just after sunset and documenting the number of bats you see. Many states track bat populations and will likely be interested in your observations.
Other ways to provide bat-friendly habitat in your own backyard include planting native plants or pollinator gardens, and reducing habitat disturbances such as outdoor lighting and tree clearing. One important but commonly-overlooked approach is to keep your pet cats indoors. Cats are natural predators, and they can have devastating impacts not only on bats, but also on other wildlife in our communities, such as native birds and vulnerable amphibians.
When we travel, it is equally important to keep bat welfare in mind. If you plan to visit any caves, mines, or other underground areas that may provide bat habitat, it’s always a good idea to ask about closures and advisories before you go. Some places are protected bat habitats, and other areas do not allow visitors during hibernation months to avoid waking the sleeping bats.
Even if you are allowed to enter a mine or cave, it is important to make sure your shoes, clothes, and gear are safely decontaminated first so you won’t spread deadly diseases like WNS. Many national parks feature caves, including Wind Cave and Carlsbad Caverns, and rangers at those sites will be happy to provide more information on how to visit caves appropriately. Always remember to report dead or injured bats to a park ranger or other wildlife official.
Worldwide, it is crucial that we continue to study bats in order to better protect them. Here at Pipestone, we recently conducted acoustic surveys, which detect and record the echolocation calls of different types of bats. From this data, we are able to learn more about the bats that use our park, and this helps us determine how to best manage these species and their habitat needs in the future.
By changing and improving policies regarding renewable energy and pesticide use across the United States, maybe we can minimize the impacts these beneficial technologies have on our wild bat populations. Perhaps we can increase the wind speeds at which wind turbine blades begin to spin to help prevent bat collisions, or maybe we can use acoustic deterrents to help bats stay a safe distance away from wind farms. If we reduce the amount of pesticides we use for agriculture, not only will we save money and keep harmful chemicals out of our soil and water, but we will allow bats to do what they do best – eat bugs!
Bats are important members of our communities, and there are many groups that support and promote bat conservation around the world. Associations such as Bat Conservation International and the Organization for Bat Conservation are great agencies for finding educational bat resources and events in your area. Consider donating to local bat conservation groups to help show your support, or attend a bat celebration event such as the Indiana Bat Festival or Bat Fest in Austin, Texas.
You can also volunteer for a citizen scientist program that performs bat emergence counts, or you can use phone apps such as iNaturalist to record observations and submit photos of sightings. But the most important thing you can do to help bats? Teach others! If you learned something new about bats today, share that information with your friends and family! Do your part to save the bats.
Together, we will teach others about how significant our flying friends are, and why they deserve a human helping hand.