Why does the white stork move south less and less

vor a few decades, the white storks were almost extinct. But fortunately, here and there, badly battered nature shows its ability to recover. The stork population has now increased significantly again, especially in West Germany. Characteristic birds – long neck, long legs, long beak – can be seen more often in Hesse and Rhineland-Palatinate in winter as well. White storks are typical migratory birds. Towards the end of the summer, they head for warmer climes and drift upstream as far as South Africa. One can only speculate why animals are now abandoning the increasingly strenuous intercontinental flight.

The Hessian Nature Conservation Union (NABU) therefore called for information about the so-called winter cranes via the web portal in November, in order to get a more accurate overview of their number and location. With the census ending at the end of January, conservationists want to investigate why white storks increasingly give up flying south in the cold season. According to NABU, especially many cranes have wintered in Hesse in recent years. More than 300 white storks were spotted in the Hessian Ried alone in the winter of 2022/2023, Bernd Petri, NABU's Hesse white stork expert, told the German Press Agency.

“We have been observing that migration behavior is changing for years,” says Petri. Accordingly, the birds on their way to Africa stayed partly in the Iberian Peninsula or entirely in Germany. There is no fear of storks wintering in this country, given that winters tend to be milder. “As a large bird, the crane is hardly bothered by the cold, because it can retain heat much better than small songbirds like titmice and sparrows – and they also spend the winter with us.”

Warmer winters mean more food

So far, little is known about the reasons for the changed migration behavior. However, it is clear that climate change is playing a role. In winters that are getting warmer and with less snow, cranes in this country also find enough mice, worms, small fish and waste in open landfills. According to NABU, cranes are not moving south because of the cold, but because of the lack of food in the European winter.

The white stork, also known as the wood stork, is one of the best known and most studied birds in Germany and is the coat of arms of NABU. It is a typical cultural follower and the only large bird closely associated with humans. In Germany and other parts of Central and Western Europe, the typical habitat of cranes is primarily agricultural grassland, in addition to ponds, ponds and wet landscapes. Due to the proximity of humans, animals have acquired a great symbolic power. Among other things, they are considered a harbinger of good luck, appear in fairy tales as “Adebar” and a symbol of pride, and even give birth in German folklore.

Storks often build their nests on roofs, chimneys or church towers. Their diet includes earthworms and insects, tadpoles, frogs and toads, as well as mice, grass snakes and lizards; even carrion is not despised. An adult stork needs 500-700 grams of food per day, which is equivalent to approximately 16 mice or 500-700 earthworms. If there are storks to feed as well, the need multiplies.

As a long-distance migrant, the white stork traditionally winters in Africa. Nearly 75 percent of German white storks choose the eastern route for their migration to their wintering grounds, which takes them through the Turkish Bosphorus to the Middle East, first to Sudan and then to Tanzania or even up to 10,000 kilometers to South Africa. Birds use warm updrafts that allow for energy efficient gliding. Since such thermals only occur with sufficient strength over larger land areas, the direct route across the Mediterranean is blocked for airplanes. The storks of southwestern Germany, like their counterparts from France, Spain and Switzerland, take the western migration route through Gibraltar and the Sahara to spend the winter in West Africa.

Spain instead of Africa

However, the migratory behavior of animals changes significantly. According to NABU, many birds flying around the western Mediterranean now stay in the Iberian Peninsula and no longer migrate further to Africa. Others don't even take off anymore. The changed behavior also has advantages for cranes. They save themselves from stress, without the risk of moving south, they are also faster in the local breeding areas than their counterparts returning from Africa and Spain, and they can claim the best nesting place.

At the beginning of 2022, the NABU Counts of Hesse showed that cranes feel particularly at home in the districts of Groß-Gerau, Wetterau and Main-Kinzig. In the Groß-Gerau district, 346 white stork litters were found, in the other two districts there were 175 and 107, respectively, both with an upward trend. At least 15 nests were still counted in the city of Kassel, and there was even a pair of cranes nesting in the Frankfurt area, although only one.