Credit: natur&emwelt
Luxembourg has what is known as a Temperate Climate in which winters are generally mild and summers comparatively cool, with rainfall that can be high; its flora and fauna have thrived in and adapted to this climate over the centuries and millennia, with ongoing challenges due to pollution and recent climate change, as well as the introduction of non-native species, resulting in disruptions to the norm.
Nevertheless, with various initiatives and organisations helping the ecosystem and habitat, including sustainability and re-wilding, there is a lot happening in nature across the Grand Duchy.
Chronicle.lu has teamed up with natur&emwelt (the non-profit organisation (naturemwelt), the foundation (Hëllef fir d'Natur) and the Wildlife Care Centre (Flegeestatioun)) for a series of articles on Luxembourg's fauna in which we look at various mammals, birds, insects, amphibians and aquatic animals, as well as touching on vanishing species returning to Luxembourg, focussing on their lifestyle and habitat, including when and where to observe them.
No. 21 in this series focuses on the Black Stork.
In the deep valley of Riedergrënn, carved by the Koulbich stream, near Redange, the black stork finds a perfect refuge. Rare and secretive, it symbolises the value of preserved wetlands.
The black stork (Ciconia nigra) is recognisable by its dark plumage with green and purple metallic sheen, contrasting with a bright white belly. More slender and elusive than the white stork, it stands about one metre tall with a wingspan of two metres. Its long red legs and bill give it a striking appearance. In flight, it glides gracefully on broad, rounded wings, often soaring silently above valleys and forests.
Lifestyle
The black stork is a shy and solitary species, thriving in secluded valleys and wetlands. Its diet mainly consists of fish, amphibians and small invertebrates, hunted along streams and ponds. A long-distance migrant, it nests in Central and Eastern Europe, but small numbers also breed in Luxembourg. Breeding begins in spring, when pairs build large nests in tall, isolated trees. They raise two to four chicks during the summer. By autumn, the birds depart on their impressive journey southwards, crossing continents to spend the winter in sub-Saharan Africa.
Habitat
The Riedergrënn valley provides excellent conditions for the black stork. Shaped like a Y, the Koulbich stream flows through wetlands, ponds, floodplain meadows and alluvial forests, restored after conifer plantations were removed. These habitats are rich in prey and offer shallow banks with vegetation ideal for hunting. Surrounded by dense forest and relative isolation, the site ensures the tranquillity that the black stork requires. Together, this mosaic of habitats makes Riedergrënn a key stronghold for the species in Luxembourg.
Where and When to See It
Elusive by nature, the black stork is never easy to observe. In Riedergrënn, it is most likely seen in spring and summer while foraging or searching for nesting areas. The best chances are along the Koulbich stream and the shallow edges of ponds. Early mornings and late afternoons are the most favourable times. By autumn, the storks depart on migration to Africa, leaving the valley quiet until the next breeding season.
Observation Tips
Patience and discretion are essential when looking for the black stork. Use binoculars, stay on marked trails and avoid approaching wetlands too closely. If you are fortunate enough to glimpse its majestic flight, simply enjoy the rare moment without disturbing this vulnerable and secretive species.
