All You Need To Know About Bats – Science Trek (Transcript)

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“Bats play an important role in our ecosystem. They help pollinate plants so we have food. They eat insects so bugs do not overwhelm us. But 25% of all bat species are threatened with extinction. Find out more about bats on this month’s Science Trek. Host Joan Cartan-Hansen and her guests, Rita Dixon and Jesse Barber, answer students’ questions about bats.”

Joan Cartan-Hansen

Bats are the only mammals that fly, and they play a very important role in our ecosystem. Find out more. We’re here to answer your questions about bats.

Join us for science trek.

Hi, I’m Joan Cartan-Hansen, and welcome to Science Trek, and welcome to Boise State University’s sensory ecology lab. We’re here to answer your questions about bats.

But, before we do, let’s learn a little bit more.

Bats are mammals. They have furry bodies. Their wings are really webbed hands with thin skin stretched from their long fingers to their back legs. Bats are the only mammals that fly. A few other mammals can glide, but bats are true flapping fliers. The fastest bat can fly at more than 30 miles per hour.

One of the biggest bats is the golden-capped fruit bat. It’s a fruit-eating bat with a wingspan of more than 5 feet. The smallest bat, and indeed, the world’s smallest mammal, is the hog-nosed or bumblebee bat. It weighs less than 2 grams and is the size of a bumblebee.

Worldwide, there are more than 1200 different kinds of bats. Bats sleep during the day and feed at night. Most bats find their food using echolocation. They make rapid high-frequency sounds. These sound waves bounce off their prey and travel back to the bats’ ears. The bats hear the echo and find their dinner.

Some bats eat things like fruit or frogs or small birds, but most bats eat insects. Little brown bats can catch 250 mosquito-size insects in 15 minutes. A bat eats about half its own weight in insects each night. If you weighed 100 pounds, that would be like eating 50 one-pound pizzas every day.

Many bats live in colonies. Their homes are called roosts. Just like you and me, bats need shelter from the weather, protection from enemies, and a place to rest. Some live in caves or trees, but others live under bridges or inside old buildings. Pups, or baby bats, are born in the summer. In the winter, some bats migrate to warmer climates. Others hibernate.

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Scientists study bats because a lot of these small flying mammals are threatened. Many bats are in trouble because people disturb them while they’re roosting or remove them from their homes. So, if you find a bat, it’s important to leave it alone.

Bats are also in trouble from a new disease called white-nose syndrome. So, if you go into a cave, change your clothes and clean your shoes and gear so you don’t spread disease from one cave to another.

Little girl: But bats can be scary.

Joan Cartan-Hansen: Ell, movies and TV shows haven’t been very nice to bats. But in china, bats are symbols of good luck. Bats are a really important part of our ecosystem. They eat lots of insects and help pollinate crops and spread seeds. Humans need bats, and sadly, about 25% of the world’s bats are threatened with extinction, so we need to do more to protect these amazing animals.

Question-and-answer Session

And joining me now to answer your questions about bats are Rita Dixon, State Wildlife Action Plan Coordinator for the Idaho Department of Fish and Game, and Jesse Barber, Assistant Professor of Biology here at Boise State University. Thank you both for joining us.

Rita Dixon: Thank you.

Jesse Barber: It’s a pleasure.

Joan Cartan-Hansen: All right. Let’s go to your questions.

Katherine: Hi. My name is Katherine. I go to Pioneer Elementary School of The Arts, and my question is, what do bats eat?

Rita Dixon: Well, bats eat a lot of different things, including blood. Some bats actually eat fish. Some eat frogs. Even some bats eat birds. But most bats eat either fruit or some kind of plant material, nectar, for example, or insects. In Idaho, all of our bats are what we call insectivorous, which means they eat insects. And some eat insects on the wing, and some eat insects that are feeding, foraging on plants or on the ground.

April: Hi. My name is April, and I go to Dalton Elementary, and my question is, why do bats hang upside down?

Jesse Barber: Well, bats hang upside down because being up high is safe from predators, and it’s a really good place for bats to be able to take off from. Bats don’t have very strong feet like birds, so hanging from the ceiling allows them to take flight really easily.

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Katelyn: Hi. My name is Katelyn. I go to Prospect Elementary, and my question is, how do bats fly?

Rita Dixon: Well, bats fly because their wings are especially developed for flight. Their wing membranes have two layers and they are tight, and so bats’ flight comes from what we call lift, thrust and drag. So, the bat wing creates something we call an airfoil which allows the bats to go up and then maintain their flight through air circulating around their wings.

Joan Cartan-Hansen: Cooper would like to know, how many fingers do bats have?

Jesse Barber: Bats have five fingers. And, in fact, the scientific name for bats, chiroptera means hand wing.

Joey: Hi. My name is Joey, and I go to Dalton Elementary School, and my question is, how many species of bats are there?

Rita Dixon: There over 1200 species of bats, and we keep discovering new species of bats, so the number continues to grow.

Dominic: Hi. My name is Dominic, and I go to Dalton Elementary School, and my question is, where do bats live?

Jesse Barber: Many bats live in caves in large numbers, but there are lots of bats that live in trees. They can live under the bark in small groups or underneath giant leaves in the tropics that they modify to make tents. And some even live all by themselves at the very top of trees hanging by one foot, and they wrap their tail around themselves to look like a pine-cone.

Rita Dixon: And I’ll add to that in terms of around the world where bats live. Bats occur everywhere except the most extreme arctic regions of the world. So, bats go as far as Alaska to the north and Argentina in the south.

Ashley: Hi. My name is Ashley. I go to Lewis and Clark, and my question is, what is echolocation?

Jesse Barber: Echolocation is how bats see in the dark. They scream out and then listen for the returning echoes from the world around them.

Rita Dixon: And to add to that, interestingly, with bats, they’re producing the sound from their larynx just like we do, but the sounds they’re putting out, unlike what we’re putting out, is what we call ultrasonic high frequency that typically we can’t hear with the human ear.

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Kenzie: Hi. My name is Kenzie, and I go to Cole Valley Christian School, and my question is, why do bats like the dark?

Rita Dixon: Bats were developed – they’re pretty much the ecological equivalent of birds except they switch shifts. And so bats have vision and they can see, but their vision is adapted more toward dim light instead of bright light. And because they use echolocation in the dark, that’s why they’re active at night.

Aurora: Hello. My name is Aurora from Dalton Elementary, and my question is, do bats have night vision?

Rita Dixon: Bats can see to some extent in the dark, and bats’ eyes are developed to illuminate things, so they’re a little different from our eyes. Our eyes are equipped more to have higher resolution, but bats’ eyes are equipped to have higher illumination in the night.

Jesse Barber: And remember that there are 1200 species of bats that make their living in all kinds of different ways. So, those that use echolocation to hunt as their dominant sense often have very tiny eyes and don’t use them very much. And other bats, that might not use echolocation to localize the insects but instead use the footstep sounds that these bugs make, also use their eyes for hunting.

Dorin: My name is Dorin, and I go to Dalton Elementary in Dalton Gardens, Idaho. My question is, what are mega and microbats?

Rita Dixon: Mega and microbats – so, when we think about bats, Jesse talked about the order of bats, which is called chiroptera or hand wing. And that’s divided into two, what we call, suborders: megabats and microbats. Megabats means large. So, the megabats are much larger bats, often with a 6-foot wingspan, whereas the microbats are much smaller, and their eyes are very different, too.

The megabats use their vision for getting around foraging and typically don’t echolocate, whereas the microbats depend almost exclusively on echolocation.


Joan Cartan-Hansen: Blind as a bat? That’s not true. Bats have good eyesight, and some bats see better than humans in the dark, and not every bat uses echolocation to find food. Megabats find fruit with their strong sense of smell.

Ashley: Hi. My name is Ashley. I go to Dalton Elementary. My question is, why do bats live in large groups?