Hello listeners. Before we start this episode with the usual introduction, I just want to say thank you so much for listening to this podcast. Thank you for following it on social media and thank you for all of your support. Especially during the COVID-19 pandemic, it really means a lot to me that you still support this podcast. When I was laid off from my job in March because of the pandemic, to fill my time, I started putting out weekly podcast episodes instead of every other week as it usually was. But now I’m back to work, so I will be returning the podcast to its normal schedule of releasing episodes every other week. This will just give you more time to think about the scientists in each episode, and to think of more questions that you’d like to ask a scientist. If you are missing your weekly dose of Ask a Scientist, we will be making fun posts on social media, including What’s It Wednesday, and Science Friday to fill the gaps in the off weeks. So keep an eye out for those. Thank you again so much for your support. And I look forward to your continued support in the future. As always, please rate and review the podcast on Apple podcasts, and don’t forget to tell your friends and family about it. And now here’s the next episode of ask a scientist.
Victoria:
Our guest this week is Dana Green. She is a wildlife biologist. She’s worked with all sorts of critters, like salamanders, armadillos, and howling mice. But her favorite group of animals are bats. She’s currently studying migratory bats in Canada, where some species of bat migrate to and from Canada to Mexico. She’s studying these bats because the more we know about bats, the better decisions we can make about them in the future.
This week’s questions were submitted by fourth grade students at Bromwell Elementary in Denver, Colorado.
Dana, thank you so much for being with us today.
Dana Green:
Happy to be here.
Victoria:
Do you have anything you want to add to the introduction?
Dana Green:
No. I just hope by the end of talking with you today, that everyone isn’t as scared as bats as they normally are, because that’s our awesome.
Victoria:
All right. Well, I think we’ve got a lot of great questions about that, that hopefully will achieve that goal.
Dana Green:
Yes.
Victoria:
(How many types of bats are there in the world?)
So we will start off with just a bunch of questions about bats in general. This first question is how many types of bats are there in the world?
Dana Green:
So the last time that I checked, there were over 1400 different species of bat.
Victoria:
Wow.
Dana Green:
And so that is second only to rodents, so mice or rats, which are the most diverse group of mammals. And bats are second, with 1400 different species.
Victoria:
(How tall are the tallest bats?)
(How much do the biggest bats grow? How big can bats get?)
(If there is a big type of bat, then what do they look like when they are full sized?)
(Can the biggest bat pick up a baby goat?)
That is super cool. So with that many species, there must be a lot of diversity in their shapes and sizes. And so we’ve got a whole bunch of questions that all go together about the size of bats. So I’m going to read about four questions that are kind of all, all in the same category. How tall are the tallest bats? How much do the biggest bats grow? How big can bats get? If there is a big type of bat, what do they look like when they’re full-sized? And can the biggest bat pick up a baby goat?
Dana Green:
I love that question. Right off the bat, pun intended.
So there is not a bat that is large enough to pick up a goat. But things like eagles could, because that is what they are for. But the bigger bats are most of the time actually going to be fruit bats.
And so they’re not going to be going after a goat. They’re going to be going after guavas, most likely.
So that’s coming all sorts of different shapes and sizes, like you said, and they are usually categorized into these two main groups, which are microbats and megabats. And I think you can kind of get an idea of which one’s going to be big. The microbats are usually smaller and eat insects. The megabats are the bigger ones. and they’re primarily going to be eating things like fruit.
And the biggest one of those is actually the name is quite descriptive. The largest bat in the world is called the large flying fox bat. And it’s yeah, it’s one of the, if not the largest bat species, it can weigh between one and a half to two and a half pounds. So even though it is quite large, it is still not the heaviest thing in the world. They’re actually quite lightweight. But they have a wingspan, that is over four feet. So like that’s pretty big for a bat. Yeah. So they’re going to have that wingspan, it can get up to almost five feet. So between four and five feet is usually their max wingspan.
And specifically, when someone has how tall the bat was, usually bats are going to be measured with that wingspan. But because I was intrigued, how tall are they at that point? So that’s tow to ahead. We are looking at, they were about a foot, just about a foot. So not that big.
And a common measurement that bat biologist uses is called the forearm length. So that is going to be right here, the forum’s going to be from the elbow to the wrist is the forearm. And that measures between about seven to eight inches, seven to eight, nine inches in length.
So yeah, so that, that is a type of flying fox. So people have, may have heard of flying fox a lot. They are definitely, extremely cute. They almost have like dog puppy like faces with big eyes, and then they have those really big wings. So that is the biggest bat.
Victoria:
(What is the smallest bat species in the world?)
(If there is a type of bat that is really small, then what does that type of bat look like when they’re a baby?)
Oh. We will include a picture of that one in the description of the episode. So click the link down below to see what it looks like.
All right, this next set of questions is on the opposite side of that size spectrum. These are about the smaller bats. What is the smallest bat species in the world? If there is a type of bat that’s really small, then what does that type of bat look like when they are a baby?
Dana Green:
I love these types of questions because it gets me looking up all of these amazing different types of bats. And I was, I have heard of this bat before, and then when I started looking into it, I was like, Oh my gosh, they really are so tiny. The smallest bat in the world is called the Kitti’s hog-nosed bat, but it is more commonly referred to as the bumblebee bats. It’s near threatened and it is only found from Western Thailand into Southeastern Myanmar, where it’s going to be found in things like limestone caves, and those types of habitats, that they’re going to be found where there’s a lot of limestone caves along rivers. And they are only one to one and a half inches.
Victoria:
That’s so tiny!
Dana Green:
That is, that is smaller than the size of your thumb, that is smaller than your thumb. So they are very, very tiny. It is the smallest species of bat, and it could potentially be depending on what people’s definition of sizes, they are also sometimes considered the world’s smallest mammal, very close to that of things like small shrews.
Yeah, so they’re going to be, there are cave roosters, so they really like areas with lots of limestone. So if you want to think of areas that have a lot of limestone in the United States, that’s going to be places like Missouri and Arkansas, where there’s also a lot of limestone and limestone caves, also lots of rivers. But again, these are only found in Asia. They, they like to hang out in pretty decent sized groups. You can find groups up to a hundred, to 500 different individuals. And they’re going to be roosting on the high walls, the domes of the cave, far apart from each other, but there’s still going to be lots of them. And they also undertake seasonal migration, similar to birds. So you have these tiny little bats making seasonal migrations from caves.
And when I did look up, I tried to find information on their offspring, on their young and their babies, but I couldn’t find anything. So this is one of those species that really needs more research done, because I don’t know how tiny their babies are, which is something I really want to know, because for a bat that is only about an inch and a half in length, could you imagine how tiny their babies are going to be? So for that one, I don’t know how small they are, and more, more research is needed. So hopefully we have some future bat biologists in the listening to the podcast.
Victoria:
Yeah, if the person who asked that question when they get older, if they want to become a bat biologist, they can figure that out and then let us know.
Dana Green:
Yeah.
Victoria:
(How long do bats live? What’s the lifespan for different bats?)
All right. Here’s another cool question about bats. How long do bats live? What is the lifespan for different bats?
Dana Green:
So this is an excellent question because I think this is something that people get really surprised about pretty often. Bats are extremely long lived. Usually they’re going to be living under 20 years, but in the wild they’re going to be living mostly between 15 to 20 years of age. But of course, that’s going to, with 1400 different species, it’s going to vary a lots. So usually between 15, 20, 15 and 20 years in the wild, however we have documented at least six species of bats that live more than 30 years. And I think around, like in the early two thousands, they recorded a bat that was 41 years old. So we’re talking like most of these bats are like really tiny, but they are extremely long lived.
Victoria:
(How do bats mate? Do they mate for life? Do mothers raise babies, and for how long?)
That’s cool. This next question. How do bats mate? Do they mate for life? Do the mothers raise babies, and for how long?
Dana Green:
Well, again, with, with, 1400 different species, you’re going to have about 1400 different ways that they’re going to be choosing their partner, their partner to have babies with. And so, there’s a bunch of different varieties.
For species that hibernate males and females will often meet for the first time that year at things called hibernacula, and hibernacula is oftentimes a cave where they are going to be spending the entire hibernation season. So a lot of the times they’re going to be meeting there in the fall, they will have kind of sporadic and spontaneous mating. And they will swarm. So bats swarm in huge numbers and they kind of chase each other, performing acrobatics. And it’s not exactly clear how exactly they’re choosing their mate, but during this massive swarm while they’re all flying around each other, they pick, they pick each other in that chaos and then they will copulate, they will breed, they will mate, and then they will hibernate for the rest of the season. And the female, the girl bat, is going to be not pregnant during that entire time. This is another one of those really amazing adaptations of bats is that they will actually delay pregnancy until the following spring. So even though they mate in the fall, they do not become pregnant until spring. So cool.
Other species, such as horseshoe bats, are a little bit more discreet in their courtship, and they do not form swarms. The females will actually visit males at their individual roosts and then select a mate.
And then there’s, there’s all sorts of different varieties. There are a few species that are monogamous and the families will actually stay together and roost together. But here in North America where that’s where usually going to be hibernating, we’re usually going to see that type of swarming behavior here in North America.
Victoria:
(How do bats use their echolocation?)
How interesting. That’s so cool.
All right, this is a really good question. How do bats use their echolocation?
Dana Green:
I always love getting this question because echolocation is one of those things that is so cool. And it’s one of the main things that has that biologists that we study how they are sensing their environments, because it is so unique.
So echolocation if you think about the word echo, and you think about the word location. It really is just those two things combined. So well, bats are vocalizing a lot of the vocalizations we cannot pick up, we cannot perceive, because the frequency is so much higher than our own hearing threshold. So human beings can usually hear frequencies up to about 20,000 Hertz, roughly, or 20 kilohertz. And whenever bats are vocalizing, they’re going to be vocalizing upwards to from like 35 upwards to a hundred. So they are very high up there. We are not going to be able to hear that, but when they’re doing it, they are screaming. They are screaming really, really loudly. And, because that vocalization is so powerful, it can travel across space and then it will hit a surface, let’s say a tree. And then that sound, sound acts like a wave, so if you think about the waves in a pool or when you drop a stone and you see that rippling, if there’s something in the way that ripple bounces back a little bit, the same thing is happening with sound. Sound is going to hit a tree, hit that tree or obstruction, and then it’s got to bounce back and the bats are able to detect that bounce back, and they are using the timing, the frequency, all of the characteristics of how that sound is hitting their ears. And you can add, they can actually build a picture in their head of what is going on around them. And so they’re doing this very loudly and very quickly as well. So they’re just flying around screaming their heads off, but they’re able to make a sound scape picture in their minds from it.
Victoria:
That is super cool. A question not from a student, but a question that I have. So I used to, before I moved to where I’m living now, I had a, I don’t know what the term is, a colony or a group of bats that was living in the wooden deck of my upstairs neighbors. And so when I would go outside, I would hear bats like kind of squeaking, like it sounded like really high pitch squeaking. So does that when they’re echo locating or are they just kind of like talking to each other?
Dana Green:
Yeah, that is like very warmly referred to as bat chatter. And that is not their echolocation calls. Those are going to be things them like just making a communication with each other. Mostly it’s them yelling at each other, like get out of my way, I need to get out of here, or those types of things. So that is, those are not the echolocation calls. It’s just a different variety of them, more of a communication. So the echolocation that is going to be for them, like maneuvering around their environments, whereas the back shatter is more of a communicative type of vocalization.
Victoria:
Okay. That makes sense.
Dana Green:
Yeah.
Victoria:
(Bats come out at sunset, but do they stay out until dawn?)
All right. Let’s see this next question. Bats come out at sunset, but do they stay out until dawn?
Dana Green:
Again, that always is going to be different between different species, but overall, they are going to be leaving at night and coming back at dawn. However, during the summertime, when they are, so when they’re not hibernating, during hibernation, they will very rarely go out if they are hibernating, because it takes a lot of energy to be able to drop that metabolic rate. And so if they get into a hibernating state, they’re most likely going to stay there for quite some time. But in the summer, when the bats are having their pups and having taken care of their babies, they will frequently go back and forth from the roost. That way they can take care of their pups. So yes, they will leave around sunsets or a little after, and they could potentially be gone the entire night. But if they have pops they need to take care of, or if they just need to rest for a little while, they will go back and forth from the roost, just depending.
Victoria:
(Are they strong?)
That makes sense. Okay. This next question is, are they strong?
Dana Green:
That’s incredibly strong. They need a lot of power to be able to lift, flight takes a lot of power and strength, and bats are the only mammal that have evolved flight. So they are incredibly powerful, and some bats are even capable of taking off straight from the ground. So there are some species of bats that do go on the ground, and they can actually just do one big powerful push with their wings and lift off. And that takes a lot of strength and power.
Victoria:
(How fast can they fly?)
Oh my gosh. Yeah.
A good follow-up question to that is how fast can they fly?
Dana Green:
That’s a really fun question. And the answer sometimes amazes me. But the Brazilian Free-tailed Bat, which does occur in North America, they are most abundant, further South in the United States and further South. They have been documented to reach speeds as they are flying out of their caves at night. And they are one of those species that have these massive, like back tornadoes as they’re streaming out of a cave, unbelievable sight to see. And when it was recorded, how fast they were flying out of that cave, they were reaching upwards of a hundred miles per hour.
Victoria:
Oh my gosh.
Dana Green:
So very, very fast.
Victoria:
(Is there a certain type of bat that normally walks on its feet?)
Wow. And, speaking of, of bats, moving around, this next question, is there a certain type of bat that normally walks on its feet?
Dana Green:
That’s a great question. And it’s not something that people think about very often because bats, you know, you think about bats, you think about them flying. But there are bats that do go on the ground. Like I said before, so a couple of species that, well, I guess one particular species that we can find here in North America, is the pallid, the pallid bat, while it does technically search for its prey while it is flying, its prey is on the ground, which are oftentimes scorpions. So they are scorpion killer bats. And they will actually fly down and get the scorpions on the ground. And they’re one of those bats that can then take off straight from the ground itself.
And then in places, like the only other place that I can think of where they have ground foraging bats is in New Zealand, where the short-tailed bats, will often forage on the forest floor, but they do still fly. They are still absolutely capable of flight. They will just fly, land on the ground, forage person insects, and then take off again.
Victoria:
(Where do the most bats live?)
(Do they have nests? Do any bats live underground?)
(Do any bats live inside hollow trees?)
(Where do bats live in the city?)
Cool. All right. we’ve got a series of questions here that’s all about how and where bats live. Where do most bats live? Do they have nests? Do any bats live underground? Do any bats live inside hollow trees? And where do bats live in the city?
Dana Green:
All right. So where do most bats live? Well, first let me, I’m going to go through some of kind of the other ones first.
Do they have nests? Yes, but we call them bat roosts, not nests, because they don’t actually like build a whole nest. It will use tree cavities instead.
Do bats live underground? Yes.
Do bats live in hollow trees? Yes.
Do bats live in cities? Yes.
They are incredibly versatile. There are species of bat that will, like you mentioned before, how you had saw, like you saw some in a house up in some rafters or something. That’s very, that’s very common, especially for species such as the that we have here in North America, it’s one of our most common species, and it is also the one that if you have bats in your house, It’s probably a big brown bat. And big brown bats, while they will readily occupy a home or attic, they will also roost in trees. They’re considered generalists really like they will just roost in all sorts of different types of habitat. So very, very versatile for the big brown bat.
And then you have some species that are strictly tree roosting species. So those are going to be examples like one of the species that I study, which is called the hoary bat is a migratory bat, and it’s kind of grouped into this clump of bats that are called the migratory tree roosting bats, which is very descriptive. It’s one, one of the things I like about the bat world, we’re very descriptive with our naming. It’s very spot on. So these hoary bats, they will roost in a lot of times spruce trees. And if you ever look at a hoary bat, they get their name because their fur almost looks like they are coated with hoar frost, which is ice that coats up on the branches, like if you ever in the early winter, if you go out and there’s like that slight layer of ice on everything, and it just looks like it’s sparkling and glittery. That’s what the fur of a hoary bat looks like. They’re absolutely beautiful, and they blend in perfectly with their roosting habitat. And they roost solitarily.
So you also have a lot of differences in who was roosting with who: some bats are very individualistic, like the hoary bat, they don’t really occur in groups; they like to roost alone, but then you have things like the critically endangered, Indiana bats, which occurs in like the Eastern and Midwestern United States. They are extremely social and will roost in caves in the, in the winter, and in trees during the summer, in large groups. So you have a lot of different variety.
And then what else did we, where do most bats live? That is definitely a preference, a depending on species, like with the hoary bats, trees; with things like gray bats, which are found throughout the midwestern United States, they are called cave obligates, they are in caves in the winter, spring, summer, and fall, cave obligate species. But, then you have amazing species like tent-making bats, again, very descriptive, they will actually in massive leaves in the rainforest, they will cut along certain points of these big leaves so that the part of the leaf drops over and creates a tent; and they will live underneath that little tent that they’ve made, until the leaves start turning brown, and then they’ll go find a new leaf and make a new tent home.
So you have all sorts of different types of roosts and roosting habits, pads, and places that they like to live.
Victoria:
(Do bats fly different from birds?)
That is so cool. Tend bat, that’s so cute.
All right. This next question is about flying again. Do bats fly different from birds?
Dana Green:
Yes, they do. So while both are considered to exhibit true flight, which means they are flapping their wings and sustaining flight for prolonged periods of time, they are doing it in very different ways.
So with, if you think about a bird’s wing, and you take away all of the feathers, what you’re looking at, you can even compare it to your own arm. They, they have all the same types of bones that we do, but everything from the whist to the fingers is kind of condensed. And then the feathers are growing out from there. And so they’re really relying a lot on that feathers and the feather shape and how those are growing to determine the type of flight.
For bats, do the same thing, think about your own arm, but rather than making those finger bones and wrist bones smaller, make those finger bones incredibly long. And then if you look at your hand, and you look between your fingers all the way at the bottom, you have that like little piece of skin there, that’s just kind of thin and it doesn’t, you don’t know, you don’t really know what it’s, it’s just kinda there, you know, it’s just that little skin bit. Stretch that out, so that it’s connecting your fingertips, and that is essentially what a bat wing is looking like. Essentially, they’re flying with jazz hands. So you just extend those fingers out with very thin skin membranes between each one of the fingers, that is what the bat wing looks like.
So they are flying with their entire hand, whereas birds are going to be flying with mostly using those feathers for direction and power.
Victoria:
(What do they do in the winter?)
Awesome. That’s such a great visual with the skin stretched all the way to the fingertips. That’s great.
This next question is what do they do in the winter?
Dana Green:
So that’s going to be very dependent on whether you have a temperate bat or a tropical bat.
So in North America, we are in a temperate environment, which means we have a lot of seasonality. We have very discrete winter, spring, summer, and fall. We have all of the seasons. In the tropics while they do have seasons, it’s kind of separated more into dry and wet, and it’s constantly warm. So you’re going to have different adaptations depending on where those bats evolved.
In temperate systems, there are going to be more likely to hibernate, and hibernation can’t, while it’s most oftentimes, especially in North America are occurring in caves, you can also still have bats that find your home and they will hibernate in your attic, which again, those are going to most likely be those big Brown bats.
In tropical systems, they’re not going to be as inclined to hibernate over the winter. And so while they might have some smaller regional migrations where they’re following fruit or nectar or insect availability, they’re not really going to be exhibiting hibernation as frequently as they are going to be in temperate systems.
Victoria:
That makes sense. And then the bats that you study that migrate, those would be temperate bats.
Dana Green:
Yes. And potentially No. So that’s that I personally study, I’m only focused on the hoary bat and the silver-haired bat, which are both considered migratory tree roosting bats.
But silver-haired bats are kind of the odd ball out, because some, some small populations will migrate really long distances, a thousand kilometers or more; or they might not. They’re kind of this weird, in-between that, it’s one of the reasons why I’m really starting to dig in and wanting to research this species is because some populations will go these really long distances and others won’t, and I’ve been really keen on to figuring out why that is. So the ones that don’t migrate as far have exhibited hibernation, so they can do it. But the ones that will migrate further South, we’re not quite sure if they are hibernating or if they are just moving into a more tropical zone.
The hoary bats, they can, like bats can hibernate. They can, they’re just physiologically capable of doing it. So while hoary bats are migrating into much warmer climate zones, they can still hibernate if there’s low resources or if there’s a cold spurt, they are still capable of doing it. In fact, a recent paper just came out that they did document a hoary bat in central Mexico, that was hibernating for days, and then it left. So they can do it, Ii’s just one of the, one of the things that we’re still scratching our heads about as to what’s going on, where are they going, why are they doing it? And every question that is attached to that.
Victoria:
That sounds like there’s so much great research to be done.
Dana Green:
Yes, there is. There really, really is. Bats have been really under studied comparatively. Like there’s a, there’s a lot of us bat researchers out there, but that’s a real, just really hard to study. Because unlike birds that will go back often to the same spot year after year after year, being able to recapture a bat is extremely difficult.
And with birds, we’ve been able to map out migrations and behaviors using GPS units in there, and little backpacks on their back, which are solar powered. Fantastic. But we can’t do that for bats, because they are active at night, solar powered technology is not going to be very useful for a nocturnal bat. And then a lot of these GPS and radio telemetry pieces of technology, they just aren’t small enough, because bats, most bats, a lot of bats are very small. And so you have to have very small equipment for them, and we just haven’t quite gotten there yet.
Victoria:
(Are there bats on every continent?)
Yeah, that makes sense.
All right. This next question is are there bats on every continent?
Dana Green:
Bats are found on every continent except for Antarctica. So they are very, very widespread and diverse.
Victoria:
(Do bats have a society? Is there a queen or a leader?)
And a good follow-up to that. Do bats have a society? Is there a queen or a leader?
Dana Green:
As far as I know, there are no bat societies that have a queen or something like that. But that’s can form pretty complex social networks. So, and, let’s say like you you’re in the middle of a forest and you have a lot of bat roosts all around you, but they could be separated by pretty far distances in this forest. But those bats are actually going to be many, some species do this, where they will actually switch from roost to roost to roost, and socialize and maintain social networks between those roosts, between nights or weeks or whatever. And that happens in temperate zones and tropical zones, and sometimes individuals that are more closely related will hang out with each other for longer periods of time. And so you have family groups, you will have friend, friend groups. But lots of, there are definitely lots of social aspects to bats and bat behaviors.
Victoria:
(Can you train bats?)
(Are there any types of bats that don’t need to be trained to act good around people?)
Awesome. Switching gears a little bit. This is getting into some more questions about bat interactions with humans. This is a pair of questions that go together. Can you train bats? And are there any types of bats that don’t need to be trained to act good around people?
Dana Green:
So in short, can bats be trained? Yes, but, in very reduced contexts. So you can’t train a bat like you’re going to be training a dog, because dogs have evolved with human beings for thousands of years. Bats are wild animals. They will always be wild animals. And while we can train them to do very simple tasks, that’s really about it. And by that I mean, we can train them to fly from one side of a flight cage to another side of a flight cage, and get an idea of how they’re flying, be able to take pictures, and do different types of research. So there’s a lot of flight research done with that type of training where bats will be sent across from one side to the other, and we’re taking video and photos and real time analysis of how they’re flying. So we can do that type of training, but we’re never going to be, well, I shouldn’t say never, I don’t think we’re ever going to get to the point where we’re going to be able to train bats like dogs.
So yes, but.
Well I think that there’s been a lot of myths out there about bats attacking people. And I think that’s probably where the, can we train bats to act good around people is probably stemming from. Overall bats are going to be just fine around people. To them, you are a big, scary monster that might try and eat them. So they’re going to avoid you at all costs. They are, they are very maneuverable and agile and, and, with that echolocation, like we talked about earlier, they can tell exactly where you are and they will try and avoid you.
Victoria:
(Do bats get tangled up in humans’ hair?)
And a good follow-up to that is do bats get tangled up in humans’ hair.
Dana Green:
Oh, this is one of the biggest myths of them all. Yes. This is just a myth. It is actually a myth that was developed to keep young girls from going out at night. So.
Victoria:
Wow.
Dana Green:
The myth was that if young women went out at night, bat would fly into their hair and get stuck. But bats are not interested in flying into your hair. They might get close while they’re searching for insects, but they’re amazing use of echolocation. It’s going to prevent them from landing in your hair and getting stuck.
Victoria:
(Do bats ever get comfortable around humans?)
(Do people keep bats as pets?)
That’s good. Good to know.
Okay, the next set of questions are about bats being very comfortable with humans and maybe not thinking that they’re they’re big, scary monsters. Do bats ever get comfortable around humans, and do people keep bats as pets?
Dana Green:
Bats can become comfortable with humans, especially if we’re talking about rescued bats. Oftentimes people have to hand care for bats that need rehabilitation, and they can develop a sense of comfort with the individuals that they’ve been working with. I follow a couple of pages on Instagram and other social medias of rehabilitators taking care of these bats and they do become quite affectionate. Bats, again, they are oftentimes extremely social, and they are mammals, so if you can think about like, we are mammals as well, and we have this slew of responses that we have to social interaction and something as simple as touch. And so they’re, while oftentimes they will start off as being a little persnickety, they can develop those types of bonds with certain people.
When it comes to, can you keep bats as pets? I would never recommend it. That’s are surprisingly stinky. So always keep that in mind. But some bats are born into captivity and therefore have to be housed in captivity from, or their entire life. This does happen, with people actually will get bats into their care from breeders, whether it’s from rescue or if they’re being used for educational purposes, but I would never say that they are ever considered pets. Because they are not, like I said before, they are not dogs. They are still wild animals and they always will be wild animals. So you have a bat hanging around your house, like it’s, it’s not going to be trained to be like going to the bathroom outside. It’s just going to do its thing and be a bat. But a lot of these rehabilitation facilities, they will also get these bats that have been born into captivity. And so that level of comfort with people is really high and they can become quite snugly.
So do you recommend having a bat as a pet? No. But they can develop affection for people.
Victoria:
(What are predators or enemies of bats?)
That’s cute. All right. What are predators or enemies of bats?
Dana Green:
Oh, that’s a good one. Bats actually have really few natural predators. The main thing that is going to be taking out bats are going to be things like disease. The biggest one in North America right now is white nose syndrome. White nose syndrome is a disease caused by a fungus called Pseudogymnoascus destructans. That is the genus and species of the fungus. And the fungus will grow on their, well, like white nose indicates it will grow on their nose, on their wings, and on the very sensitive tissues. And so things like that are going to be more likely to be causing mortality in bats.
But when it comes to predators, there’s very few. Sometimes owls will take out bats, but it is not their primary food resource. They’re going to be sticking with small, with other small mammals on the ground, because bats are hard to get, they’re very agile in the air, so they’re hard to get.
But you can see things like snakes and hawks and falcons trying to get bats as they are streaming out of the caves at night. So if you have a big, big, big colony of bats, and they’re all exiting a cave at the same time, some snakes will hang out at the cave entrance and just kinda hang, literally hang there, and they will nab bats as they are streaming out of the cave. And things like hawks and falcons will dive down into this massive swarm of bats and try and pick out one. So that’s, it’s just kind of in your bets, hoping that with these thousands of bats coming out of a cave, that you can get just one.
Victoria:
Image of the snakes hanging to get the bats is quite scary.
Dana Green:
Yeah. I highly recommend checking it out. It’s really interesting to watch.
Victoria:
(What animals are related to bats?)
(Are flying squirrels related to bats in any way?)
We’ll see if I can find a picture or a video to link in the episode description.
All right, let’s see here. What’s next? What animals are related to bats? Are flying squirrels related to bats in any way?
Dana Green:
So first I’ll start off with a flying squirrel question. Flying squirrels don’t fly. Flying squirrels are a gliding mammal that gives the illusion that they are capable of flying, but flying squirrels will actually just glide from tree to tree, to tree. So very short distances and it’s not sustained. So they can’t flack their arms and legs and fly, like a bat can, they can just hold out their arms and their legs, and they have a big patch of skin that stretches from their wrist to their ankle and they spread that out and glide. So that’s what flying squirrels are doing. So the name is very misleading. And there are type of rodents and rodents and bats are very, very distantly related. They are really not closely related at all.
The, the closest group that that’s, that it’s thought of bats are most closely related to, which is also a misleading name, is that they are most closely related to this group of organisms called flying lemurs, which are not actually lemurs. They are mammals, so they do have furs, they produce milk, just like most other mammals, or all other mammals having for and producing milk. But they’re only going to be occurring throughout the Philippines, there are very small order of mammals called Dermoptera. So that is the order Dermoptera, there’s only two species in the entire order. So it’s very, very small, very small regional distribution there in the Philippines. And yeah, that the flying lemurs, if we think about that flying squirrel again, how it has skin stretched between its whist and its ankle, very similar to what a flying lemur is going to look like as well. And so the way that they are, they are also considered a gliding mammal. So they’re going to stretch out their arms and their legs, and they will glide from place to place.
Victoria:
They have a very misleading name on both fronts, not flying, not lemurs.
Dana Green:
You take a hint from the rest of the bat biologists that are very descriptive with the naming.
Victoria:
(Are any bats very colorful or just all brown?)
All right. This is a fun question. Are any bats very colorful or are they all just brown?
Dana Green:
What a good question. There are brown bats. There are black bats. There are white bats. There are orange bats. There are red bats. There are striped bats. There are polka-dot bats. There are big bats. There are little bats.
There are so many, different shapes and sizes and colors of bats. I, if you want to imagine it, then odds are there’s a bat like that out there for you. There is one called the badger bat, which is black and yellow, very amazing species. There is the painted bats, which is bright, bright orange with black accents.
The bat wing itself can come in a variety of different colors as well. It can go from black and fade to a translucent white almost. You can get a little, you can have bright, almost pink wings as well. So really there is just all sorts of different varieties. Not I mean, bats are not just brown. They are almost every color underneath the rainbow.
Victoria:
(I have heard that bats started COVID-19, is that true?)
(If it is true, how did they cause it?)
(Have they started other diseases or problems?)
That is amazing. Switching gears a little bit. We’ve got a couple of questions about diseases and bats. So the first question is, I’ve heard that that’s started COVID-19. Is that true? And if that is true, how did they cause it? Have they started other diseases or problems?
Dana Green:
I’ll have to, just trying a little bit lightly here. I guess I can start off with saying that there has been a lot of stories out there saying that COVID-19, coronavirus, came from bats there are lots of different types of coronaviruses, COVID-19 is just one different type. And bats have been documented to carry different types of coronaviruses. There has been no direct evidence that COVID-19 came from bats. It is one of the hypotheses of where COVID-19 came from, but it has not been fully supported yet. So we, we don’t know.
But bats are oftentimes an easy animal to blame, and they are getting a lot of that right now. And a lot of us bat researchers are, we’re really trying to pick up the pieces from that kind of fallout because they are time and time again, bats get demonized because type of thing, and while they can harbor a lot of diseases, when push comes to shove, it is because of people. That is how these diseases get spread.
So scientists are still trying to uncover the source of COVID-19 specifically and bats are being considered, but humans are really what causing how these coronavirus or other types of disease get transferred from wildlife into our human populations because of illegal poaching, the wildlife trade, and selling and eating wildlife species.
So bats are a really unique type of animal, and they have a really unique physiology, which is how their organs are all working, how, how all of their body is working and functioning. And they are able to do amazing things like hibernation. So hibernation is when you reduce your metabolic rate so, so low that you become practically immobile. You’re in this highly reduced state, and because you are in that state, you have to be able to deal with things that are coming at you while you are hibernating for weeks or months. And so they’ve developed these amazing physiological abilities to cope with different types of diseases. And that is the whole, that whole field is still being heavily, heavily explored. And we don’t know exactly why they’re capable of dealing with these diseases. But when people trap and consume bats, bats can deal with these diseases, humans can not. So if we want to stop this spillover from bats to people, then we have to put in more protections for bats. We have to put in more protections into the wildlife trade, and we need to research bats more, because the more we understand, the more we will be able to prevent this from happening again.
Victoria:
(Are vampire bats real?)
(Are vampire bats rare?)
All right. This is a set of questions about vampire bats. Are vampire bats real? And are vampire bats rare?
Dana Green:
Yes. Vampire bats are real. I would not consider them necessarily super, super rare.
In the United States and in Canada, we don’t have to worry about vampire bats. Are vampire bats going to come after you and drink your blood? No, it’s not going to happen.
There are actually three different species of vampire bats and you can find them all in Mexico and further South than that. So they’re not going to be coming up here. They’re more of a warm temperature type of species. But even where they range, odds are they’re not going to be going after people because we’re difficult. You know, we, we get something that think about how you react when a mosquito bites you, do you think you would put up with a bat coming up? No, of course not. So they’re more likely to be going after things like livestock. Because a cow isn’t going to care so much. They’ve got that big hide.
And so when a vampire bat does feed, they are making the tiniest little prick. And taking the tiniest amount of blood. They are really not consuming that much, and they’re not going to be going after people most likely, and all in all, they’re actually one of the most interesting species bats out there because of their very, we were talking about sociality in bats before. So it seems like a lot of people are interested in the social aspects of bats, and vampire bats are some of the most social. They have large, large colonies and they are considered an altruistic society. So they will actually feed each other. So sometimes if you’re not feeling well and you’re kind of sick, you’ll have someone come to your home and bring you some soup and they just want to feed you to make you feel better. Vampire bats do that. So if there are some individuals who just, they don’t have the energy to go out, looking for their own food that night, another vampire bat will come to them, and actually regurgitate what they have eaten and feed it to the other bat, to keep them surviving, to keep, to help, help them live, and make it through the next day or two. So some consider them to be an altruistic society, and there are some of the most interesting social networks in bat research. And yeah, there’s some of my favorite species.
There is also one other type where the naming was a little misguiding as well. There is a bat called false vampire bats, which is not a vampire, but they are actually predatory. So they will actually, they will, they will fly and capture other small mammals. They will capture other bats, small rodents, and eat them. So they are actually a predatory type of bat. Also found further South Mexico and further South as well.
Victoria:
Cool. I love the vampire bats taking care of each other. That’s so cute.
Dana Green:
Really cute. It’s really, really cute. And It’s kind of like a pay it forward system.
Victoria:
(Why do you study bats?)
All right. We’re winding down to our last three questions here. And these are all about you and your study of bats. So this first question is why do you study bats?
Dana Green:
Well, I have always had a soft spot for the underdog. And I, as I mentioned before, bats for so, so long and continuing to today, they get demonized a lot. And they don’t deserve it either. They’re demonized and they don’t deserve it. Bats are, are some of the most diverse, amazing species that we have on this planet. They comprise a quarter of all mammalian species. So think about every mammal in the world, about 25% of those are all bats.
Victoria:
Wow.
Dana Green:
The group is huge. And they’ve always kind of been an underdog, which pulls my heart strings to them a little bit. And then, that’s also super weird. I mean, I talked about all of the different, a lot of the different varieties, the shapes, the sizes, the colors. They come, they get weird. That’s get very weird. Especially if you started looking at their faces and their ears, you can have big ears, little ears, lots of weird, like folds and wrinkles in the ears, and everything has purpose. And if you look at that faces, you have some noses that are almost smushed back into the face. You have noses that form this massive leaf shape, and other ones that’ll make this big spike. All of these different noses, ears, faces, face shapes, head shapes, and they get weird. And I have always been kind of a weird person. So to also see a bunch of mammals that are just as weird as I am, it just pulls me to them.
Victoria:
Oh, that’s cute.
Dana Green:
(Have you ever been bitten by a bat?)
All right, this is, potentially a fun question or a scary question. Have you ever been bitten by a bat?
Victoria:
Very good question. We are, we are taught from a very young age that if you find a bat on the ground, don’t pick it up because of it might bite you and get rabies. Any like almost any mammal can bite you. And if it’s rabies, then it can transfer that. The percent of bats that actually carry rabies is under 1%. So it’s very, very low. But whenever you start getting into bad biology and you start wanting to get into that field, something that is absolutely required before you start working with bats is you get a rabies vaccine. There is a pre, there’s two different types: there’s a pre-exposure and a post-exposure. Pre-exposure means I’m going to be working with some wildlife that potentially carries deadly disease. So I’m going to take this ahead of time, and then you can get booster shots if you need them, you can go and get your titers checked, which is going to exhibit your, your response if you get exposed. So you can get boosters. So I am rabies vaccinated. I was, I’ve been rabies vaccinated for a very long time, so I don’t have too much concern. And then the post exposure is I just got bit, I need to get vaccinated. But you have to do that pretty quick.
So have I been bitten by a bat? Yes. Hundreds of times, hundreds of times. But I do wear gloves. I wear gloves, to prevent the teeth actually making contact with my skin. But you know, sometimes it just happens, and you just deal with it. But it doesn’t really hurt that much because again, the bats that I work with are very tiny. And so they only have tiny little teeth and odds are they’re not even going to be able to break the skin.
So while I have been bitten, I have also been rabies vaccinated. And when I think about this, I think I mentioned this a little bit earlier before, when I think about this, when I have a bat in hand, which I mean, I I’m looking at it, I’m holding it, I’m measuring the wings and doing everything I need to do as a bat scientist, I am a giant, scary monster to that bat. I have a big light on my head cause it’s nighttime. I’m shining it in this bat space. I’m holding it. I’m messing with its wings. It is terrified of me. What would like, imagine putting yourself into that situation, what would you do? You try to get away. So if I have a very unruly bat that is really trying to get at my fingertips, I understand, because to it, I am a giant scary monster, but most of the time we do immediately rerelease these bats and then they get to go on and live their happy lives.
So, yes, I’ve been bitten, but I have been vaccinated. And I also understand that to the bat, I am terrifying. So we do try and minimize the amount of time that we hold bats, because by reducing the amount of time that we are actually holding the animal, we’re reducing that risk of getting bitten, and we’re also reducing the risk of too much stress on the bat. So very, very quick processing, most of the time.
Victoria:
(What’s your favorite bat?)
Yeah, that makes sense.
And then this is our last question. What is your favorite bat?
Dana Green:
Okay, so I kind of have two answers here.
So out of the bats that I have personally worked with, my favorite species is the silver-haired bat. The silver-haired bat is, one, it’s beautiful. it has jet black fur and frosted tips. It just is beautiful to look at. And then it’s that really weird species where some populations will migrate these really long distances and others don’t. And I just want to know why, why we see this difference.
But if we are talking all of the bat species, then my favorite is probably going to be the wrinkled faced bat, which I suspect you are going to look up. And when you look at this bat, you’re going to probably your first thought might be ill. Because it is not very attractive. At least to our human eyes, that’s not attractive. Cause I’m sure to like some, some lady wrinkled face bat seeing a super wrinkly faced male bat is going to be like the best. They have the most interesting faces. They are wrinkly and kind of bubbly looking, they’re smushed in, like they are not a very attractive bat. And then they also have these like flaps of skin that they will, the males will put over their face. And it’s they, they suspect it’s because of it’s a mate attraction behavior. I just get so curious. Why do they look the way they do? I could stare picture of a bat for probably trying to think of all of the evolutionary reasons as to why is the face smushed in, why do they have all of these wrinkles, why are they putting that flat look skin over their face? So they’re my favorite because they peak my curiosity so, so much.
Victoria:
That’d be awesome. I’ll include a link to a photo of them in the description of the episode, so everyone can check them out.
Dana Green:
They are very, very weird looking.
Victoria:
All right. So that’s all of our questions, but do you have any questions of your own for the listeners.
Dana Green:
I guess my, kind of a question and a comment is are you still scared of bats? Cause I hope not. They’re just amazing. They’re amazing critters and there’s so many different kinds.
Victoria:
Yeah. Yeah. They are incredible. I’ve learned so much. This is fascinating.
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