Many stork-clumps on chimneys and roofs are already abandoned. An empty nest, however, does not mean the departure of the birds to the south. First, the storks collected, said stork expert Kai-Michael Thomsen from the German Nature Conservation Union (Nabu). First of all, the young storks roam about. The very sociable birds then meet at prominent points – in northern Germany, for example, in the Elbtalaue, or the Eider-Treene-Sorge river landscape, explains the biologist. “Then they go off in sunny weather on any day and disappear.”
The annual trip to Africa is innate to the storks
For white storks as a glider, according to Nabu, a good thermals is important. They used the late summer with plenty of sunshine, which heats the ground to high in the air and then to be able to sail long stretches. This way, the animals can travel up to 500 kilometers a day.
The annual trip to Africa is innate to the storks. According to Nabu, it is not the cold, but the food shortage in winter, which drives the animals to take on the exhausting flight to the distant winter quarters.
The journey to the south, the storks usually come on two different routes. Either they cross the Mediterranean in the west via Gibraltar, and then spend the winter in West Africa. Or they move across the Bosphorus and the Middle East to North Africa, from there along the Nile to the East and South African wintering areas. The dividing line between the eastern and the western pulls goes according to the Nabu right through Germany. He learns which path each individual takes on his first journey.
“The exact route is not innate to them. Only the pull: we have to go now, and to the south, “explains Thomsen. For example, Russian ornithologists would have provided young storks with transmitters in experiments. Their GPS data showed that the young birds first moved south. “When they hit moving storks, they were pulled along – either east or west.”
This combination of innate and learned behavior allows the storks to respond to environmental changes. In the past few years, more and more white storks on the Western route have refused to visit Africa and wintered instead on Spain’s dumps: Because there is much to eat, says the Storchenexpertin at the Federal Association for Bird Protection (LBV) in Franconia Hilpoltstein, Oda Wieding. Some even stay in Germany. (Wolfgang Runge, dpa)