Why there are currently so many storks in the skies above Zug

This summer, a striking number of storks are causing a stir in the canton of Zug. Livio Rey and Beda Schlumpf know why.
 

Up to 14 storks can sometimes be seen at once in the fields around Zug. This rare sight is providing plenty of talking points. ‘The large number of storks is a hot topic in the village,’ says Hans Aregger, a reader from Menzingen.

For around ten days, he has seen large groups of these birds stepping through the fields in the Neugrund area every morning and evening, a phenomenon he has never observed before. But where do these large groups of storks come from?

Livio Rey, media spokesperson for the Sempach Bird Observatory (Vogelwarte Sempach), knows that these are white storks, also known as the stork that brings babies or the lucky charm ‘Adebar’. Their breeding grounds are partly located in the high plains of the canton of Zug, such as Menzingen or Neuheim, but also along watercourses such as the River Lorze or in nature reserves.

‘The white stork's breeding season is now over and this year's young have flown the nest,’ he says. In addition, the storks' migration season is slowly beginning, and will really get underway in August.

It’s not surprising that more storks are seen on freshly mown meadows such as those in the Neugrund area. ‘They search for dead or injured mice, grasshoppers and so on there,’ he adds.

Beda Schlumpf, head of the Hunting and Fishing Department at the Zug Office for Forestry and Wildlife (Abteilungsleiter Jagd und Fischerei des Amtes für Wald und Wild Zug), knows why there are often large gatherings. ‘Young storks and non-breeding adult storks gather in groups, known as “flocks” or “roosts”, to prepare for their onward migration, especially in late summer and autumn,’ explains Livio Rey.

The stork was threatened with extinction
The fact that there have been more storks around in recent years is a positive development, however. ‘Just 70 years ago, the white stork was extinct in Switzerland, but today it can be seen again in many places, striding across meadows and fields. There are many reasons for this success,’ says Livio Rey.

Storks prefer open landscapes with wet meadows, fens, ponds and extensively farmed land as habitats
Archive photo: Soraya Sägesser
Storks are often seen in large groups                          Archive photo: Severin Bigler
They can often be seen on the rooftops of Zug         Archive photo: Stefan Kaiser

One reason is the decline in mortality among adult birds, which has been confirmed by analyses carried out by the association ‘Storch Schweiz’ (Stork Switzerland). According to Livio Rey and Beda Schlumpf, however, the main reason is the great commitment of volunteers to preserving these birds. Many outdoor stations have been set up for storks, where they can breed peacefully, and other successful protective measures have also been put in place.

Not everyone is enthusiastic about the strong growth of the white stork population. This is especially true because the storks no longer stay only at the long-standing stations, but often also at new locations. ‘We still have a good overview,’ says Livio Rey, ‘but without new volunteers, this effort cannot be sustained for much longer.’

In some places, the term ‘problem stork’ is already circulating, because some people are quite overwhelmed when such a large bird lands on the roof of their house. On the one hand, this is due to the mess caused by their droppings, and, on the other, because of the noise they make when clattering their beaks. ‘But the noise is usually only temporary and limited in extent,’ says Beda Schlumpf.

The stork itself also has problems to contend with. Above all, the intensification and modern methods of agriculture are responsible for the fact that these wading birds are unable to provide their young with sufficient food nowadays. Further difficulties arise from their preference for wet meadows, which are increasingly being drained, from collisions with overhead power lines, and the use of pesticides and hunting pressure.

The storks stay in Zug in the winter
More and more storks can be seen in the canton of Zug, even in the winter. Beda Schlumpf explains this with climate change: ‘The birds' migratory behaviour has changed significantly over the last few decades.’ Winters in Switzerland have become milder, so the wading birds often stay here. This saves them the risky journey to Africa, which in turn increases their chances of survival and means that more storks can be seen in Zug in summer.

‘Storks play an important role in environmental education in the canton of Zug and raise awareness among the population about nature and species conservation. That's why it's great to see more storks,’ says Beda Schlumpf.