Eerie lodgers populate the Zug night sky

A Daubenton’s bat in flight. (Image: Dietmar Nill)

They shy away from the light, like to be cuddly, are familiar with echolocation and ultrasound, eat between a third and a half of their body weight in one night and are as loud as a rock concert, although we humans hardly ever hear them. The bat, also known as the Queen of the Night, is astonishing in its versatility.

Person writing

Stefan Fighting

14 interested participants gather in front of St. Michael’s Church in Zug at dusk. The reason is a bat excursion by the “Wilde Nachbar Zug” project. The setting couldn’t be more appropriate: the church front and the large tower rise gloomily into the Zug night sky.

No bloodthirsty Draculas

The right place and time to clear up some myths. Isabelle Bögli from the Zug Bat Protection quickly makes it clear that the bat is anything but a Batman or a vampire. She patiently answers all questions, such as whether bats actually drink blood.

“There are three different species of vampire bats that cut open the skin of chickens or cows to lick the blood that comes out. However, these species are only native to South America.” Depending on the species, the local bats actually feed primarily on insects such as mosquitoes and moths. But spiders and centipedes are also on the menu.

Isabelle Bögli with a bat specimen and a drawing of a bat skeleton. (Image: Liane Wittwer)

Deep floorboards or naughty children?

A second widespread myth was once heard mainly by children. If a bat ever gets caught in your hair, it’s almost impossible to get rid of it. “That’s a fairy tale, of course,” smiles Isabelle Bögli, and tries to explain the reason for this statement herself: “It could be because people used to live in houses with low ceilings right below attics. And maybe someone got their hair caught on a bat every now and then. Or it was a trick used by parents to stop their children from walking around alone in the dark.”

Sugar cube-big old man

In general, many people have only half the knowledge when it comes to the nocturnal flying acrobats. Isabelle Bögli asks the group how many mammals there are in Switzerland. The answers vary greatly. In fact, there are 99, and 30 of them are bats. 16 of the species known in Switzerland live in the canton of Zug. The smallest animal – the sibirica with a wingspan of 20 centimeters – is just as big as a sugar cube. The greater mouse-eared bat, on the other hand, has a wingspan of 40 centimeters.

Isabelle Bögli keeps the interested group on their toes in an interactive way and poses the next guessing question: “How much does the smallest and how much does the largest bat weigh?” Eager guessing, and here too the answer is astonishing: the weight of the local bats ranges from a minimum of 4 to a maximum of 40 grams. To make people aware of the small size of these featherweights, Bögli passes around small bags of sugar eggs.

The estimates made are also off the mark when it comes to the question of how old a bat can become. “Many species of bat live to be half a dozen years old or more,” explains Isabelle Bögli. “Some have records of over 30 years. The oldest bat known in Europe lived to be 43 years old.” This triggers a respectful murmur from the group. At this point, even those who were not bat fans before are now fans of the little night owls.

“Where there is room for a thumb, bats can live”

During the day, bats rest. Contrary to what you might think, they don’t just hang upside down in attics or church towers; their homes are as varied as their skills and talents. “Bats can live anywhere there’s room for a thumb,” says Bögli, and gives a few examples: “That can be in cracks in walls, piles of wood, bridge supports, mountain railway houses or in caves.” But most of the time, these cute little creatures aren’t that far from their own homes. “They often nest in blind boxes.”

Fast 250 Kilogramm Kot

“You notice it especially when there are tiny balls of droppings on the windowsill.” And depending on the number of animals, this can quickly take on larger proportions, as Bögli explains: “Where I live in Mühlau, seven 35-litre garbage bags full of bat droppings were once swept out of the church.” No wonder, because the little bats are real eating machines.

Isabelle Bögli illustrates this with a pizza box she brought with her and a small math problem. The question is: “How many pizzas would a child weighing 30 kilograms have to eat per night if it were a bat? Would you know? No? It would be about 30 pizzas at 333 grams each.”

Hunting with ultrasonic direction calls

To give the group an idea of ​​how bats get their food, the group moves away from the church and directly into the neighboring hunting area near a small city stream. Bats are the only mammals in Switzerland that can fly. These skilled flying acrobats can orient themselves at night thanks to echolocation and at the same time silently hunt for insects.

So that we can still hear them, Bögli distributes bat detectors, a device that makes ultrasound audible. “Bats can be up to 100 decibels loud, and yet we usually can’t hear them because their calls are too high for our hearing,” notes Isabelle Bögli. “They move in a frequency of 17 to 130 kilohertz. A child can hear up to 20 kilohertz. As we get older, it can go down to 10 kilohertz.”

Isabelle Bögli distributes bat detectors. (Image: Liane Wittwer)

Nervous clicking and fluttering circles

And indeed: On the way from the church to the Zuger Landsgemeindeplatz, it doesn’t take long before our devices go off. The nervous clicking is usually followed by a quick glimpse of a bat fluttering dangerously close to our heads. A quick turn later, it disappears again into the dark undergrowth. Without these devices, it would probably be much more difficult to catch a glimpse of the shy animals.

Big enemies: cats and humans

When you watch and listen to these versatile night owls, it is hard to believe that almost all species native to Switzerland are under threat. In addition to birds of prey such as owls and falcons, their enemies include martens, cats and humans. The latter mainly because of light pollution, the use of pesticides or because bat habitats are destroyed when buildings are demolished or renovated.

Bat finds – react correctly

Bats are shy wild animals. They fly away from people. What should you do if you find a bat? If the bat is obviously weak or injured, please contact the cantonal bat care center. Here, injured, weak or young bats are professionally cared for and released back into the wild as quickly as possible. The bat emergency telephone number for the canton of Zug: 041 758 07 34. The bat protection emergency telephone number for Switzerland: 079 330 60 60. The telephone number of the cantonal bat protection officer: 077 423 91 28.

Sources used

• Visit to the bat excursion in the city of Zug of the project «Wilde Nachbar Zug»
• Discussion and interview with Isabelle Bögli from the Zug Bat Conservation Association

Person writing

Stefan Fighting