All streams on Medvednica are endangered due to construction in their vicinity, aggressive hydro-technical measures that alter their appearance, polluted wastewaters and waste disposal. Streams in karst terrains are particularly endangered because all surface pollution leaks into the underground, thus polluting the streams. That is why we put a lot of our effort into the preservation and protection of streams.
The name of the mountain guards the memory of bears, magnificent animals which haven’t lived in the forests of Medvednica for centuries. Due to the spreading of settlements, destruction of habitats and increasing utilization of mountain goods, many other species such as lynx, wolf, deer, grouse and otter have vanished from Medvednica. We can still find them only in the names of many villages, streams and areas such as: Medveščina, Medveščak, Medvedski breg, Vučje jame, Vukov dol, Risovo polje, Risnjak, Orlove stijene, Jelenovac, Jelenja voda etc.
It makes us happy that at least some toponyms on Medvednica, such as Lisičina, Srnec, Mačkova pećina and Mačji kamen derive their names from animals still living on Medvenica today. The mountain somehow managed to resist the pressures of a million-people city surroundings and preserve conditions necessary for development of extremely interesting fauna, which has since the second half of the 19th century caught interest of numerous biologists. Since the Public Institution was founded, a lot of effort has been put into systemic research of the animal world and monitoring of the condition of certain species and habitats.
Many species of mammals, from small rodents such as mice, rabbits, dormice and voles, to big ungulates such as roes and wild boars, still inhabit the forests of Medvednica. Several species of carnivores are present in the Park: wildcats, foxes, martens and weasels. Even though they are small, these carnivores are true hunters. They are active mostly around dusk and during the night, when they prey on small mammals or birds and their eggs. If they are close to human settlements, they sometimes “rob” hen houses, or due to food shortage, “attack” the leftovers of human food. While foxes do it frequently, the wildcat almost never visits people. It is a strict carnivore and very nocturnal. The wildcat is larger than the domestic cat, and we can also tell them apart by wildcat’s black mouth and feet, and very hairy ear interior.
Among Medvednica mammals, bats are particularly interesting. 24 species of bats live within the Park area, 7 of which are Natura 2000 species and 1 nationally important species. We can find these bat species in caves, abandoned mines, quarries, tree hollows and house attics. All bat species in Croatia are protected by law; therefore, it is forbidden to disturb them. Even though bats are featured in many scary myths, these flying mammals are completely harmless to people. Even more so, they are doing us a huge favour because they feed on insects which can cause severe damage to plants, and they find some real “nuisances” such as mosquitoes a real treat. The fact that one bat can eat 600 mosquitoes in one night says a lot!
All bats hibernate during the winter. Some species spend winters in colonies in Veternica Cave, while others inhabit tree hollows. That is why the state of forests is extremely important for their survival.
18 bat species have been observed in the Veternica Cave. For this reason visits to the cave are forbidden during the winter, in order not to disturb the bats in this sensitive period of hibernation, when their vital functions slow down and their body temperature is only a few degrees above the temperature of the surroundings. An incautious visitor might jeopardize the survival of these sensitive animals – for only one awaking a bat spends as much energy as it needs for three weeks of undisturbed sleep! To protect these interesting animals and their cave home, the park employees set up a special bat friendly grate fence at the entrance of the cave. This fence provides undisturbed passage to the bats and prevents unwanted visitors from entering the cave.
The sky above Medvednica is dominated by birds of prey such as the common buzzard (Buteo buteo), northern goshawk (Accipitper gentilis), common kestrel (Falco tinnunculus) and Eurasian sparrowhawk (Accipiter nissus). We are particularly happy when we see the rare European honey buzzard (Pernis apivorus).
Unlike them, many birds on Medvednica lead a secretive life in dense forests. Such are the numerous passerines, who revitalize the forests every spring with their singing. In the bird world, singing is a male task: the males seduce the females with complex melodies every day, defend their territory or simply mock their neighbours. The most common passerines on Medvednica are the common chaffinch (Fringilla coelebs) and European robin (Erithacus rubecula). Tits are also common, especially in the winter when they gather into big flocks.
Several other interesting bird species live by the streams of Medvednica. The European dipper (Cinclus cinclus) occupies a special place amongst them; it almost never leaves its stream and immediate surroundings. It nests near fast mountain streams with lots of little waterfalls and rocks where it swims and dives in search for food for its family. In the old days, 2-3 pairs of dippers used to live by each Medvednica stream. Nowadays, there are only about 10 pairs on the whole mountain. The cause of this are constant changes of their habitats: regulation of water streams and water pollution.
Amphibians and reptiles
The scientific name for amphibians is Amphibia, which in old Greek means “both kinds of life“. These coldblooded animals spend the first part of their lives in water, breathing through gills like their ancestors – fish. When they grow up they make a transition to the mainland and start breathing air. All amphibians are very sensitive to pollution and other changes in the environment. That is why we call them bioindicators – their populations rapidly reflect the state of the environment.
Several species of amphibians live on Medvednica. Frogs, which inhabit damp areas of the Park (streams, ponds, puddles), make their presence known by croaking. The biggest one amongst them is the common toad (Bufo bufo), which can grow to be 20 cm long. A much smaller species, the yellow-bellied toad (Bombina variegata), marked as a Natura 2000 species, looks a lot like the common toad from the upper side. If you try to get too close to it, this little toad will try to chase you away: it will bend its front and back legs backwards to reveal its bright yellow belly with black spots, in order to warn you that it is not a tasty or a harmless prey. Even though this toad’s venom is not dangerous to people, it is recommend you wash your hands after you’ve touched it.
The same recommendation applies to the black-and-yellow fire salamander (Salamandra salamandra). You can find this animal in shady and damp places, especially after rain, which is why it is known as “snebac“ in Vugrovec area – the one who has fallen from the sky. During dry periods it comes out of its dens at night, to hunt for small invertebrates. Unlike amphibians, reptiles are not tied to water for their reproduction; they are completely adjusted to life on the mainland. Lizards and snakes are the most common reptiles on Medvednica. Several species of these reptiles live on the mountain. The longest one (it can reach 2 meters) but not the most dangerous one amongst them is the Aesculapian snake (Zamenis longissimus). This snake is completely harmless for people. It is a very skilful climber so sometimes it is possible to see it wrapped around a thin tree, just like it is displayed in the famous symbol of pharmacy and medicine, the Rod of Asclepius.
The sand viper (Vipera ammodytes), our best known viper, also lives on Medvednica. It is very easy to recognize it by the horn on its snout and zigzag stripe on its back. Its colour and the shape of the stripe can vary. Despite its name (“jumper” in Croatian), you needn’t be afraid this snake will jump on you as soon as you see it. Just don’t disturb it or touch it. Its natural enemies are smooth snakes (Coronella austriaca), which feed on young sand vipers, and hedgehogs, who are so skilful they can catch an adult sand viper by dodging its venomous bite.
All reptiles on Medvednica are protected by the law, which means that disturbing and catching them is forbidden.
The fauna of invertebrates on Medvednica is very diverse and represented by a large number of species. Those are mostly insects who with their activity help to establish and preserve the natural balance of the mountain.
Such is the red wood ant (Formica rufa), a typical inhabitant of woods, which avoids open spaces and human settlements. Walking through the forest we can come across their steep anthills made of needle leaves, branches, dry leaves and dirt. The red wood ant is a very useful inhabitant of woods because it feeds on different forest pests. When an overpopulation of a certain forest pest, for example the Gypsy Moth, occurs, the red wood ants are often the ones who feed on them. While the Gypsy Moth caterpillars wreak havoc to the entire forest by eating leaves, the trees near anthills are completely preserved.
The meadows, glades and edges of Medvednica’s forests are embellished by many beautiful day-flying butterflies such as the Old World swallowtail (Papilio machaon), Scarce Swallowtail (Iphiclides podalirius) and the Purple Emperor (Apatura iris). Some of the most beautiful ambassadors of the Natura 2000 network and nationally important species are the butterflies of Medvednica. They include the large copper (Lycaena dispar), marsh fritillary (Euphydryas aurinia), large blue (Phengaris arion) and Fenton’s Wood White (Leptidea morsei) butterflies. The day-flying butterflies are endangered due to the loss of their favourite habitats, meadows, which are not mowed regularly.
Some species of beetles are second to butterflies in the beauty department – for example the Rosalia longicorn (Rosalia alpina) and longhorn beetle (Morimus funereus), which are with their grey-blue colour perfectly adjusted to their favourite habitat – beech forests. The stag beetle (Lucanus cervus) and hermit beetle (Osmoderma barnabita) prefer old oak trees. The mentioned beetles are on the Natura 2000 species list, and are therefore strictly protected by the law.
Apart from many species of beetles, a large number of spider species also inhabit the meadows of Medvednica; 25 species of spiders were observed for the first time in Croatia exactly on Medvednica.
Medvednica is rich with springs and streams of the mountain type: their upper course is steep and their lower course is more flat. A typical riparian vegetation is developed along these streams, and the stream fauna includes a number of endangered and endemic species, as well as a few Natura 2000 species.
Fish are relatively rare in Medvednica streams, but we can still find several different species: the Danube barbel (Barbus balcanicus), schneider (Alburnoides bipunktatus), European chub (Leuciscus cephalus) and brown trout (Salmo trutta var. fario), among others.
Trouts and dippers love to feed on caddisfly larvae which have adapted to life in fast mountain streams in a unique way: in order not to be swept away by the current, the larvae build a case on their bodies. This case is made of silk, which then holds small rocks, sand grains or small branch fragments. Burdened with these “weights” of their own making, the larvae hide under stream rocks, praying on food.
The stone crayfish (Austropotamobius torrentium) also inhabits the streams of Medvednica. Only thirty years ago the population of these crayfish was high, but in recent years it has started to decline. The stone crayfish are sensitive to changes in the environment and are considered good indicators of the quality of water. Freshwater crayfish represent an important link in the food chain of stream ecosystems.
Small amphipods such as the endemic Niphargus elegans zagrebensis and Niphargus tauri medvednicae from the Dolje and Bliznec streams are also protected by the law.
Several crustacean species of groundwater and thermal sources fauna have been observed in the Medvednica area.