Bats are funny creatures. They fly crazy distances, some drink human blood, most fill us with fear and they can pee upside down. On International Bat Night, DW spoke with a scientist all about his favorite mammal.
On International Bat Night, events are planned across Europe to raise awareness about these creatures, their state in the world, and also measures being taken to help preserve them. Suren Gazaryan, a Russian scientist, has been studying bats for just about his entire professional career. He works at the UN-coordinated EUROBATS office in Bonn, the European headquarters of an international bat protection convention.
DW: What do you find most fascinating about bats?
Suren Gazaryan: [Laughs] Good question. As a scientist, I know so much about bats that it's pretty much impossible to single out one thing that is especially exciting to me. But a good place to start is long-distance migration - just how far bats can fly - this is a very interesting and unique aspect of bats.
Are you talking about continuous flight? How far can a bat fly?
They can migrate distances over 2,000 kilometers (1,200 miles), but, of course, they stop on the way.
So how would a bat get across the Mediterranean?
Easy. Because they can fly so fast - up to 50 km/h (31 mph) - they can cross the Strait of Gibraltar with no problems, approximately two or three hours. This is how many bats commute between Africa and the Mediterranean region of Europe. This has been confirmed by genetic analysis, as well as studies that incorporate bat-binding using metal rings. This has been stopped, because it might be harmful for them.
In general, do bats move around a lot?
Well, there is a huge variety of bat species in the world. If you speak generally, we can classify them in two groups. Sedentary bats essentially stay put around one home, be it a cave or a cellar, attic, etc. These bats only move around this one place, known as a roost. Migratory species, on the other hand, they travel great distances between two different roosts, one for reproduction and the other for hibernation.
They head east to do their dirty business - and then they come back here to sleep it off?
I would not call it dirty business. It's just their normal lifestyle. For bats, it's much more comfortable to reproduce outside of Europe where it is so overpopulated.
It's better for the males or the females?
For the females, of course! They need more space, they need more food, and they can spread their wings a bit. Males tend to stay back home in Europe. It's the females who perform the migration to eastern Europe; some travel further, in some cases even northern Russia.
You say that western Europe is overpopulated by bats. But why, then, are efforts to preserve bat species here taken so seriously?
Right, so with that said, the populations are definitely declining. There are many reasons contributing to this decline, chiefly among these is habitat degradation. Also, there are global climate factors at work. But in Europe, the most dangerous factor is human development. To sum it up, bats are suffering from human activity.
How important are bats for wildlife, or even for us?
It's exceedingly difficult to estimate the precise role they play in ecosystems.
Could we survive without bats?
[Laughs] Yes, I think so. We could probably survive without wildlife. But European ecosystems, especially tropical ecosystems, are greatly affected by bats. They consume huge amounts of insects, so they regulate the natural balance in forests, and also they're important for agriculture.
But bats are pretty small - how many insects can they eat?
A normal bat can eat more than 1,000 mosquitoes in one night.
In one night? What!?
They need much more energy than people do. So, they have to eat intensively. And pregnant bats eat even more. One colony of reproducing females can eat several kilograms of insects per night.
From a biological perspective, let's say a bat eats over 1,000 mosquitoes; it must have to relieve itself. And they sleep upside down. Just how does a bat do that?
Well, first of all, they can pee and perform their bowel movements in flight. And when they're in their roost, they just curve their tail and make it like this [gestures with arms between his legs].
So they just move their tail out of the way? They don't have to flip upside down or do any other stunt?
Actually, they do it like other mammals, like you or me…
Yeah, but I don't sleep upside down!
Just imagine that you're fixed to the ceiling. What will you do?
If I had my feet fixed to the ceiling and I urinated, it would probably run down my entire body…
No, you just have to bend your ... [gestures with hand].
You've devoted most of your professional career to bats. Can you give us a sense of what they mean to you?
[…] I perceive them like they are my friends. I have been working with them for so long and have so much experience with them.
Have you ever been bitten by a bat in a cave?
Yes, many times, many times. If you are bitten, you should seek medical assistance, but it's not dangerous, usually. If a bat finds its way into your home, the best thing to do is remove it. You should wear gloves, of course, but it's not dangerous. There are many superstitions, e.g. that they will fly right into your hair, but this is simply not true.
My mom is deathly afraid of bats. She has chiroptophobia - the fear of bats. Why do bats inspire this kind of real fear?
I don't know about this. In China, for instance, bats are a good omen. I think this is cultural. Perhaps it is religious…
What about Dracula - could the reason be that bats drink human blood?
There are only three species of true vampires, but they live in South America and Central America. There are no vampires in Europe. If there any vampires in Transylvania, then these vampires are definitely humans. They are not bats.