Storks: Villages with dozens of nests – with sometimes strange consequences

GA sign at the entrance to the village warns: “Caution! Storks flying low!” That is meant as a bit of a joke with a view to the tourists who come to the village of Uehlfeld because of the many storks. But just a few meters further on, you can see that the warning is no coincidence. Everywhere on the roofs they rattle white storks. They have built five nests on the church tower alone. Again and again one of the white-black sails birds majestically from roof ridge to roof ridge – and across the main road that runs through the middle of town.

“We currently have 53 nests,” says Detlef Genz, mayor of the approximately 3,000-inhabitant community in northern Bavaria. “As far as I know, more than in any other place in Germany.” However, that cannot be said with certainty. But there are already a lot, says the stork expert Kai-Michael Thomsen from the Michael Otto Institute of the German Nature Conservation Union (Nabu) in Bergenhusen. With 25 nests, the community in Schleswig-Holstein has a larger colony itself, but has just under 730 inhabitants.

Once was that white stork almost extinct in Germany. According to Thomsen, around 10,000 pairs of storks are now breeding nationwide. In recent years, the population in western Germany has increased significantly, says Thomsen. The federal states with the most storks are Baden-Württemberg and Lower Saxony. In the east, on the other hand, the stocks are stable at best, in Mecklenburg-Western Pomerania they are even declining. And this development has consequences: “If there is great population pressure, colonies can develop in favorable locations.”

Just like in Uehlfeld. Gerhard Bärtlein, 74 years old, grew up with storks. He can still remember times when no stork showed. But for years there have been more and more – also on his property. Five pairs of storks are currently breeding on its roofs. It would probably be many more if it hadn’t stopped nest building in unsuitable places at an early stage. “Perhaps word has got around in the stork world that life is good in Uehlfeld?” he speculates.

Scientifically, the behavior of storks difficult to study, so experts can only speculate. “It’s a really crazy thing,” says Wolfgang Fiedler from the Max Planck Institute for Animal Behavior in Radolfzell on Lake Constance. In the first few years, a breeding pair will try everything to defend its territory. “But when a certain density is reached, it’s like a lever being pulled. But what exactly happens between aggression and colony formation is not entirely clear.” Similar behavior has been observed in mute swans on the Thames in London.

According to Fiedler, the increasing colony formation of storks could also be related to the changed migration behavior. The number of storks flying to the winter quarters via the western route has increased. About two-thirds of them no longer fly to Africa at all, but spend the winter mostly in Spain, where sufficient food can be found on landfills. These storks therefore have much better chances of surviving than the east migrants, who traveled many thousands of kilometers more – sometimes as far as South Africa.

“Since the number of west migrants has increased, it’s teeming with stork villages,” says Fiedler. Especially in the south and south-west of Germany, villages with more than ten pairs of storks are no longer unusual. And that could have an impact on the return of the storks to Germany, he suspects. The west migrants, who would have to cover a shorter distance, could be on the nest as early as mid-February. “As density increases, there is greater pressure to come back sooner. Whoever sits on the nest first always has an advantage.”

The storks in Uehlfeld have boosted tourism: day trippers and hobby bird watchers are enthusiastic, but some residents are less so. Even Gerhard Bärtlein, who says he has a big heart for storks, says: “That’s enough now.” Because once the birds have decided on a location, it’s not that easy to dissuade them again. This is particularly problematic when they build nests on heated chimneys or on the top edges of solar panels, says biologist Oda Wieding from the State Association for Bird and Nature Conservation in Bavaria.

Three years ago, storks paralyzed the small brewery of the Zwanzger brewery inn in Uehlfeld because they were breeding on its chimney. Another time the chimney of the inn was blocked, says boss Susanne Zwanzger – and she had to turn off the heating in March and the guests had to freeze.

In Dinkelsbühl, about 100 kilometers away, storks even triggered a fire brigade last year: According to the city, the vent did not work in a museum because of a stork’s nest on the chimney and the carbon monoxide pollution increased. The fire brigade then removed some nests in the old town for safety reasons.

Such problems will have to be dealt with more intensively in the future, predicts Nabu expert Thomsen. In Uehlfeld, by and large, they have come to terms with the storks, says Mayor Genz. “Many many. And I think most of them always enjoy the sight of the storks.” In addition, the colony cannot keep growing, he says. “It works itself out naturally.” Thomsen also confirms this: “At some point the competition is so great that there are more fights and the storks throw each other’s eggs out of the nest, or the stress in the colony means that the breeding success is not so great.”

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