Continental wetlands & rivers
Despite being a largely forested country, Slovenia has also some excellent wetland sites. Most wetlands are continental, with only a few lying on the country’s short stretch of coast. Certainly the most famous and interesting is the temporary karstic lake (or “turlough”) of Cerknica, in the Notranjska region. This place has an exceptional biodiversity due to its varied landscapes with lake, reedbeds, wet meadows, channels, forest and farmland. Being temporary, the lake is full of water only after heavy rainfall (usually in autumn and spring).
Northeastern, lowland Slovenia has many interesting freshwater wetlands, typical of the Pannonian region. Although most of the lakes, marshes and reservoirs in the Štajerska region are man-made, they are extremely rich in birds and other wildlife and include areas such as Ptuj and Ormož lakes, the Medvedce reservoir, the Ormož, Rače and Vrbje fishponds.
Wetlands are a real paradise for birds either for breeding, wintering or as stop-over sites during migration. Among the most interesting breeding birds in continental wetlands are the Ferruginous Duck Aythya nyroca, Spotted Crake Porzana porzana, Little Crake Porzana parva, Black-necked Grebe Podiceps nigricollis, Red-necked Grebe Podiceps grisegena (only at Cerkniško jezero), Snipe Gallinago gallinago, Curlew Numenius arquata (Slovenia’s only population at Ljubljansko barje), Little Bittern Ixobrychus minutus, Bittern Botaurus stellaris, White-tailed Eagle Haliaeetus albicilla, Marsh Harrier Circus aeruginosus, Black Stork Ciconia nigra, Common Tern Sterna hirundo, Mediterranean Gull Larus melanocephalus, Grasshopper Warbler Locustella naevia, River Warbler Locustella fluviatilis and Savi’s Warbler Locustella luscinioides. Many wetland sites with wet meadows also host important populations of Corncrake Crex crex, Quail Coturnix coturnix and Yellow Wagtail Motacilla flava. The latter species is interesting because in Slovenia you can commonly observe several subspecies: cinereocapilla, feldegg, flava; more rarely also thunbergii and superciliaris. Cinereocapilla and feldegg are the commonest breeding subspecies.
In winter the freshwater lakes and reservoirs attract large numbers of wildfowl, the most interesting of which include Smew Mergellus albellus, Goldeneye Bucephala clangula, Greater Scaup Aythya marila and Velvet Scoter Melanitta fusca (small numbers, but regular). More rarely, Long-tailed Duck Clangula hyemalis, Whooper Swan Cygnus cygnus, Bewick's Swan Cygnus columbianus, Lesser White-fronted Goose Anser erythropus and Red-breasted Goose Branta ruficollis are occasional winter visitors.
On migration literally anything can turn up, but certainly species worth of mention include White-winged Tern Chlidonias leucopterus, Glossy Ibis Plegadis falcinellus, Spoonbill Platalea leucorodia, Garganey Anas querquedula, Pygmy Cormorant Phalacrocorax pygmeus (a resident, but so far non-breeder), Osprey Pandion haliaetus and a large variety of waders.
Many other birds like herons, egrets, ducks, waders and gulls can be observed in Slovenian wetlands, but can't all be listed here. Most of the common European waterbird species are present in Slovenia either as breeding birds, in winter or as passage migrants.
Ferruginous Duck Aythya nyroca (Photo: Jure Novak)
Spotted Crake Porzana porzana
Pygmy Cormorant Phalacrocorax pygmeus (Photo: Jure Novak)
Red-necked Grebe Podiceps grisegena
The wetlands are also rich in a wide variety of species of amphibians, for example the common Marsh Frog Pelophylax ridibundus, Edible Frog Pelophylax esculentus, European Tree Frog Hyla arborea, Yellow-bellied Toad Bombina variegata, European Toad Bufo bufo, Green Toad Bufo viridis, Smooth Newt Lissotriton vulgaris, Northern Crested Newt Triturus cristatus and Fire Salamander Salamandra atra.
Rarer amphibians, mostly found in the wetlands of eastern Slovenia include Common Spadefoot Pelobates fuscus, Fire-bellied Toad Bombina bombina, Danube Crested Newt Triturus dobrogicus, while the Italian Crested Newt Triturus carnifex and Italian Agile Frog Rana latastei are mainly found in western Slovenia. Among reptiles the species most linked to water include Grass Snake Natrix natrix, Dice Snake Natrix tessellata and the increasingly rare European Pond Terrapin Emys orbicularis.
A whole variety of dragonflies, water beetles and other insects, too numerous to mention here, are also typical for Slovenian wetlands.
European Pond Terrapin Emys orbicularis (Photo: Dušan Klenovšek)
Common Spadefoot Pelobates fuscus
European Tree Frog Hyla arborea
Dice Snake Natrix tessellata
Plant communities in freshwater continental wetlands are very rich and characteristic. Here we will only list some of the most interesting plants living in or close to water: Water Lily Nymphaea alba, Yellow Water-lily Nuphar lutea, Water Violet Hottonia palustris, Horned Pondweed Zannichellia palustris, Water Caltrop Trapa natans, Fringed Water-lily Nymphoides peltata, Frogbit Hydrocharis morsus-ranae, Mare's-tail Hippuris vulgaris, Water Soldier Stratiotes aloides, Whorl-leaf Watermilfoil Myriophyllum verticillatum, Common Bladderwort Utricularia vulgaris, Utricularia australis, Water Knotweed Polygonum amphibium, Great Yellowcress Rorippa amphibia, Common Bullrush Typha latifolia, Typha shuttleworthii, Common Reed Phragmites australis, Four Leaf Clover Marsilea quadrifolia, Water Plantain Alisma plantago-aquatica, Arrowhead Sagittaria sagittifolia, Yellow Flag Iris pseudacorus, and Elocharis carniolica.
Yellow Flag Iris pseudacorus
Mare's-tail Hippuris vulgaris
Water Violet Hottonia palustris
Fringed Water-lily Nymphoides peltata & Water Caltrop Trapa natans
Slovenia is also known for its numerous rivers, many of which are still clean and largely unpolluted. The rivers Sava, Drava and Krka are certainly the most impressive and flow mainly through lowland areas. Along their courses they form important wetland sites. The most interesting for migrating and wintering birds are certainly the reservoirs of Ptuj and Ormož on the Drava. The river Mura in extreme northeastern Slovenia has still preserved some of its natural features such as the meanders, the numerous oxbows and large areas of riparian forest. But the purest and cleanest rivers are those that originate and flow in the alpine region, such as the Soča, Tolminka, Idrijca, Kokra and many others.
Bird species encountered along rivers in the mountains include Dipper Cinclus cinclus and Grey Wagtail Motacilla cinerea, while Goosander Mergus merganser, Kingfisher Alcedo atthis, Sand Martin Riparia riparia, Common Sandpiper Actitis hypoleucos and Little Ringed Plover Charadrius dubius are more typical for lowland watercourses.
The most interesting species of mammals found on Slovenian rivers include the elusive Otter Lutra lutra, more numerous in the east of the country and the Beaver Castor fiber which is slowly colonizing parts of southeastern Slovenia.
Some Slovenian rivers host good populations of the Marbled Trout Salmo marmoratus, an endemic fish found in the Adriatic basin (mostly Slovenia and northeast Italy). The most important sites for this species include the river Soča and its tributaries (Tolminka, Zadlaščica, Idrijca) in western Slovenia. In Slovenia there are three native freshwater crustaceans: the White-clawed Crayfish Austropotamobius pallipes, Stone Crayfish Austropotamobius torrentium and European Crayfish Astacus astacus.