The damned reservoir on the Vah River, Sĺňava, was built at the end of the 1950's on the south-eastern border of Piešťany. Although it was created for strictly utilitarian reasons as a reservoir for the Madunice hydro-electric plant, it soon became apparent that this 430-hectare surface of water could be of some importance to birds, for many different reasons.
The winding course of the Váh River valley is an important migration route for birds. Species that live on or near the water use this body of water as a stopping station during their spring and autumn migration. During the autumn, this stop might last a few days, weeks or even months. Some species on Sĺňava even remain throughout the winter. Among these migrating birds are several types of ducks, geese, grebes, herons, redshanks, sandpipers and other species which either live on or near the water. Ones that have increased the frequency of their visits in recent years include the whooper crane and cormorant.
Among the rarer guests to visit Sĺňava are the Purple Heron, Night Heron, Ruddy Shelduck, Common Eider, Parasitic Jaeger, Long-tailed Jaeger, Loons (Red-throated, Arctic, Common), Common Crane, and White-tailed Eagle. Whooper Swan and Great Cormorant can also be included among the species that have increased their frequency of occurrence here.
A completely separate chapter could be devoted just to the birds that winter on the bodies of water found around Piešťany. This issue has been given special attention by ornithologists and there exists a wealth of scientific literature on the subject. Thanks to favourable micro-climate conditions, which are related to the thermal springs, and the favourable location of Piešťany, the water in many places does not freeze, even during the most frigid temperatures, which enables these birds to survive their most difficult time of year. Sĺňava clearly ranks among the most important wintering spots for birds in Slovakia.
After the completion of the damn, conditions for nesting birds were lacking. The situation began to improve, when, in the 1960's, Viliam Kubán, who dedicated his life to the research and protection of birds on Sĺňava, created a green enclave on the right shore of the embankment. Over time, these places created a real oasis for bird life. Among the birds found nesting here are the warbler, penduline, ducks, swans, and many other species such as the Little Bittern. After 1972, the opportunities for nesting expanded even further, when, thanks to the piling up of excavated gravel, a small island in the middle of the reservoir was formed. Yearly, over 7,000 pairs of Black-headed Gulls nest on the less than three hectares of this little island. In professional circles there is aroused attention and reports that, in a relatively short time, three species of gulls, which had never before been registered as nesting birds in Slovakia, can now be found nesting here - Caspian Gull, Common Gull, and Mediterranean Gull. The greatest rarity, however, to be found on Bird Island is the nesting colony of over 70 pairs of Common Tern. This is an endangered species in the EU.
Confirmation of the exceptional value of this site with regards to the existence of rare species of birds led to the incentive to include Sĺňava in Slovakia's network of protected areas in 1980. The surface of the protected area is 691 hectares, of which the damn itself is 430 hectares. Today, there can be found here, among other things, the largest concentration of gulls in Slovakia. That is why this site has been legally included among the important bird territories within the European Union. In addition to the thermal springs, this is another immeasurable gift that nature has bestowed upon Piešťany.
The protected area of Sĺňava not only deserves our attention and respect, but also our help, care and consideration.
Author: Kornel Duffek
Photographers: František Bača, Dušan Knap