The 48 km2 of the Lac du Der-Chantecoq constitute a haven of peace for more than 300 bird species. Since the 2000s, and the worsening of global warming, more and more of these animals have been wintering in the lake area each year. Several covered shelters have been set up along the shores so that the public can observe them without disturbing them. The conditions are therefore right for the birds to reproduce in spring in complete tranquillity. Classified as a Natura 2000 site, the Lac du Der has been a national hunting and wildlife reserve since 1977.