“Don't be afraid, the worst they'll do is shit on you,” says ecologist Robert Henning, leading the way into the muggy glass enclosure with a torch and a banana.
A 400-year-old fortress seems like a fitting location for a bat lair, and the dark basement of Berlin's Spandau Citadel is home to more than 200 of the fluttering nighttime creatures.
As soon as the bats smell the fruit, they swarm, tugging away dainty bites, alighting on hands and deftly avoiding collisions. It's a peculiar feeling, but their velvety fur and breezy wings are more fairylike than vampire.
These are South American fruit bats, on display for visitors and children's birthday parties at the Fledermaus Keller, or bat cellar, an educational centre co-founded in 2003 by Henning and other volunteers with a passion for protecting bats.
Here people of all ages can meet the creatures up close and take tours of the grounds to learn more about the gentle animals, which have throughout history been the unfortunate victims of irrational fears of evil and disease.
The surrounding citadel houses some 11,000 bats during their winter hibernation roost, making it one of Europe's most important bat habitats, according to Germany's Nature and Biodiversity Conservation Union (NABU). The environmental group began a nationwide bat protection campaign in 2001.
Winding through the dank arched corridors deep inside the fortress, Henning explains that most of the bats leave for their summer quarters in the springtime. But a few males remain behind to get first pick when females return for autumn breeding, he says, pointing his torch at a few sleepy-eyed furballs dangling in high caverns.
Twenty-one different bat species – all insectivores – are found in Germany and these greater mouse-eared bats are just one type of furry flier that make Berlin home to more bats than any other central European city, according to NABU.
“Bats are plentiful in Berlin because it is so expansive and green, with big old trees – even right in the city centre,” Henning explains. “The bats like to live in tree hollows. And there is also lots of water, which they like too.”
The city, still somewhat ramshackle in parts even 20 years after German reunification, also offers plenty of war bunkers and drafty old buildings, which are favoured as roosting spots.
Endangered by tidiness
But a changing environment, habitat destruction and a general lack of knowledge mean that even though they have few natural predators, every German species remains endangered, says Dr. Christian C. Voigt, a bat expert at the Berlin-based Leibniz Institute for Zoo and Wildlife Research.
“Many homes where they lived have been renovated,” he says, explaining that bats are extremely sensitive to roost disturbance. “Germans like to clean up and keep things tidy, tearing down old buildings, but it destroys bat habitats.”
A growing chorus of bat activists including Henning and Voigt aim to educate the public about just how important the tiny creatures are – even for urban environments.
“Bats take on the nighttime position that birds take during the day. Without them eating all the insects and pests they do the city would be unliveable,” Henning says, describing how Daubenton's bats, which hunt near water, can gulp down up to 4,000 mosquitoes per night. They also provide other ecosystem service functions such as seed dispersion and pollination.
In March, the German wildlife foundation (Deutsche Wildtier Stiftung) teamed up with a Protestant foundation for nature protection to install “bat inns” on church belfries, which were once a favourite roosting choice for the nocturnal mammals. The state of Saxony supports a campaign to put seals on bat-friendly buildings called Fledermaus komm ins Haus, or “Bat, come into the house.”
Meanwhile major German cities have municipal environmental protection officials, who quietly work on behalf of bats.
Dr. Regine Grafe heads this effort in Berlin, training and consulting with construction companies about their legal obligation to protect habitats, fielding calls from residents who may have found an errant bat, and working to create new roosts as old sites fall victim to progress.
“The modern facades with their glass and steel are naturally no place for bats,” Grafe laments. “So we try to balance the situation by creating roosts nearby, hoping that they move in and monitoring the sites afterwards.”
Occasionally people find the animals in their homes and her office gets a frantic call from a resident that betrays dying superstitions about the animals.
“There are these old wives' tales about how you have to shave your head if they come in contact with your hair, and they want to know what to do,” she laughs.
The rabies question
One fear is however valid, the experts said. Some bats do carry rabies, but human infection is extremely rare and can be avoided with a simple booster shot from a doctor.
Despite lingering ignorance, the educational efforts are slowly working.
“Children are no longer afraid of them, because their parents aren't telling them scary stories and there's a lot of positive literature out there now. They're gaining a better standing in society,” bat cellar founder Henning says while feeding grubs to injured bats brought to the centre by concerned residents.
But there have been some setbacks – like the city of Dresden's decision to build a a new bridge over the Elbe River last year, which could endanger the habitat of a special Horseshoe bat, and the recent destruction of a roost in Berlin's Biesdorf neighbourhood by a crew of careless tree trimmers.
“Overall Germany is doing very well, though,” says bat expert Voigt, describing a wealth of research underway in the capital. “Bats are all over Berlin, flying along the streets, hunting at street lights and ponds, all you have to do is open your eyes and look up.”