The little ringed plover, or Charadrius dubius, as ornithologists call the species, is slightly larger than a sparrow and has brown feathers, its underparts are white. You can recognize him well by the distinctive yellow eye ring around the dark eyes and the black collar. The short beak is also dark, the legs are brown-yellow in color. Like so many other native migratory birds – the ringed plover mostly winters in the southern Sahara – the species was once widespread in Bavaria. However, the number of specimens in this country has been shrinking dramatically for years. The ringed plover is now classified as endangered on the Red List. The reason for the decline: Over the past 200 years, at least four fifths of the habitats of Charadrius dubius have been lost.
The little ringed plover lives – as its name suggests – on the rivers in Bavaria. It hunts worms, spiders, insects, larvae and small mollusks on their gravel and sand banks and in the shallow waters of the shore. It also builds its nests in the hollows of gravel banks. Starting in April, the females lay four well-camouflaged stone-gray to cream-colored eggs in them; the ringed plover pair incubates them together over the course of about three and a half weeks.
Once upon a time, the Charadrius dubius had plenty of living space. “The Lech, for example, originally had a bed that was up to a thousand meters wide with gigantic gravel banks, between which it continually dug new paths,” says Fabian Unger from the State Association for Bird Protection. “It was very similar on the Isar and of course on the smaller Upper Bavarian mountain rivers such as the Loisach, the Ammer or the Halblech.”
Today the gravel banks have disappeared except for a few, mostly miserable remnants. The reason: Since the middle of the 19th century, the rivers in Bavaria have been straightened and canalized, weirs have been built into them and hydroelectric power plants have been built on them. The former freely meandering wild rivers have become – at least for most of the year – confined, sluggishly flowing waters. The Lech, for example, resembles a string of reservoirs in many sections.
With the gravel banks, a habitat with a unique biodiversity has been lost. It’s not just the little ringed plovers that live on the inhospitable scree and rock, where it becomes almost unbearably hot and bone dry in summer, but which can be flooded after a heavy downpour in the mountains. But a whole range of other highly specialized plant and animal species. The German tamarisk, for example, a rod-like, widely branched shrub up to two meters high with fine gray-green foliage, only occurs on gravel banks. Or the lavender willow, which can even grow up to 20 meters high.
But the spotted snare insect also feels comfortable on gravel banks. It is one of the largest locust species in Europe, but its appearance is rather inconspicuous. The river bank wolf spider or Arctosa cinerea is completely different. “It can frighten bathers on the gravel banks,” says LBV man Unger. “Because it is one of the largest spiders here and seems really dangerous to some people with its grayish, spotted body.” The dark gravel bank grasshopper, on the other hand, is a delicate appearance. It is also on the red list and is threatened with extinction.
To ensure that all of these species have a future, the LBV has recently started a project. It’s unwieldily called “Bavaria’s Rarest: Species of Dry Habitats” and is scheduled to run for six years. Within its framework, the LBV wants to improve the conditions for the highly specialized gravel bank flora and fauna in the area between Lech and Isar. There are still a few river sections there with comparatively intact, extensive gravel banks. First of all, of course, the Rißbach, which flows into the Isar near the Karwendel town of Vorderriß. Or the Ascholdinger Au and the Pupplinger Au on the Isar near Wolfratshausen. In addition, individual sections on the upper Loisach, the Ammer and the Halblech and their tributaries.
Unger and his colleagues will record the endangered flora and fauna everywhere. But that’s not all. They want to improve the habitats by, for example, cutting down pastures so that the German tamarisk has more space again. Or by keeping bathers and walkers away from breeding ringed plovers. They are also seeking collaborations with gravel pit operators. “It turns out that more and more ringed plovers are turning to gravel pits as a replacement habitat,” he says. “We now want to check whether this is also possible for other species such as the tamarisk.”
Anyone who thinks that the project is a somewhat strange hobby of ornithologists is mistaken. With their biodiversity, gravel banks are a habitat that must be preserved and improved under European nature conservation law. Germany and thus Bavaria are obliged to actively contribute to this – especially since, for example, the German tamarisk in this country practically only occurs on the mountain rivers in Upper Bavaria and the Allgäu. Therefore – if the LBV did not do it – the Free State or the federal government would have to start a project to preserve them. With its project, the LBV is, so to speak, a service provider for the state. The subsidies he receives for this – the federal government covers around 580,000 euros, the Free State 115,000 – do not even cover the costs. The LBV has to shoulder a small share itself.