Especially when the weather is nice, day-trippers and athletes populate the Isar meadows in droves, where they can find relaxation and amusement in the beautiful nature. What is a preferred local recreation area for them serves as a vital retreat and breeding area for quite a few animal species, such as the rare little ringed plover and the endangered sandpiper, for whom the Isar valley is their living room and nursery.
As every year, the lower nature conservation authority of the district of Munich is appealing to hikers, joggers and cyclists to exercise particular sensitivity and consideration, especially in the coming weeks, i.e. to avoid the breeding grounds of endangered birds.
The intensive leisure use on the gravel banks of the Isar by bathers and walkers as well as the landing of boaters posed a particular threat. In order to be able to protect the breeding sites in a targeted manner, the birds were therefore observed intensively from the beginning of the courtship display and it applied to the breeding areas during the period From March 15th to August 10th, a ban on entry with severe fines in the event of non-compliance, according to a press release from the authority. The areas between Kloster Schäftlarn and Buchenhain are marked with yellow signs and marking tapes.
Dogs must also be kept out of the restricted zones. Garbage left behind also poses a great danger, as it attracts foxes to the gravel banks at night, which will not spurn a bird chick when they are looking for food. And don’t miss the eggs that the little ringed plover lays in a nest hollow on bare gravel islands or gravel banks.
The gravel breeders had already experienced better times, which the district office draws attention to. Until well into the 19th century, extensive gravel and sand banks, which constantly changed their shape, extent and position due to frequent flooding, would have characterized the floodplains of the Bavarian rivers. The Isar transported large amounts of gravel from the mountains to the foothills of the Alps and deposited them in extensive floodplains along the course of the river. Numerous animal and plant species have adapted to the wide, sparsely vegetated gravel banks and islands and have found breeding and habitats there.
With the expansion and straightening of rivers and the construction of power plants, however, the picture has changed dramatically. The species, which specialize in open river meadows, would have lost large parts of their traditional habitats as a result. Although a change of direction had already begun in the late 1980s and more space was given to the river again, but despite all efforts, the breeding sites for sandpipers and little ringed plovers, which were once abundant, are still extremely rare and their breeding sites are becoming increasingly rare due to the rapidly increasing recreational use in Danger.
The results of the most recent Bavaria-wide population survey showed how dramatic the situation is, especially for the common sandpiper: The population in Bavaria was already very low in 2012 with around 150 breeding pairs. After that, it dropped to fewer than 100 pairs in less than ten years by 2021.
“There is a threat of extinction of a characteristic species of the Bavarian wild river landscapes,” writes the district office and also points out that the Isar is probably the most important remaining breeding area for the common sandpiper. The situation is not quite as dramatic for the little ringed plover, of which there are only around a thousand breeding pairs left in Bavaria, but which also breed on man-made gravel areas away from rivers and streams.
The district office is therefore appealing to the population to help “so that the calls of these rare bird species in the wild river landscapes in the Isar valley and in Bavaria do not fall silent”. The common sandpiper can be recognized by a slightly sloping “Hii-dii-dii-dii-dii”, the ringed sandpiper’s call sounds something like “piu” or “pri”.
Information on the subject of gravel breeders and the Isar is available from the Munich district office (e-mail: [email protected]) and at https://www.alpenflusslandschaften.de/de/isar.html.