Biodiversity is defined as the diversity of living organisms or the diversity of all living world (Kazimir Tarman quoted in: Biotska raznovrstnost Zemlje, Proteus, October 1998).

The term can be explained as the diversity of living organisms, regardless of their source, including mainland, marine and other ecosystems, as well as the complex ecological systems these organisms are a part of. Furthermore, the term also covers the diversity within a species, the diversity among various species, as well as the diversity of ecosystems (Convention on Biological Diversity). Thus, the term covers all forms of life on Earth – from viruses to tropical forests. To sum up, the term is made up of the following 3 levels: the diversity of species (number of species), the genetic diversity within species (the number of representatives of the same species), and the diversity of living environments (habitats).

Why does diversity of living creatures matter?

Biodiversity is the source of numerous goods and benefits for humankind. People only become aware of many of these goods and benefits once they are lost.

  • Biodiversity provides food, fuel, oxygen,
  • shelter and construction materials,
  • clean air and water,
  • detoxifies and contributes to the decomposition of waste,
  • contributes to a stable and favourable climate,
  • reduces the negative effects of floods, drought, extreme temperatures and heavy winds,
  • creates and restores the fertility of the soil,
  • pollinates plants, including numerous agricultural crops,
  • controls pests and illnesses affecting crops,
  • preserves genetic resources that are essential for the development of new species, medicines and other products,
  • provides cultural and aesthetic benefits,
  • gives the ability to adapt to changes.

More: Economics of Ecosystems and Biodiversity


Orchids are the most extensive family of plants. According to data from a guide published in 2015, Orhideje Slovenije (Orchids of Slovenia) by Branko Dolinar, 79 species and subspecies grow in Slovenia. Depending on the type of environment they grow in, orchids are classified as grassland or forest plants, and as species of dry or marshy soils, while some only grow in highland areas. Our data shows that in the Kozjansko region, 4x(?) species and subspecies of orchid have been found so far. The majority can be found on thermophilic highland dry grasslands and thermophilic forest slopes.

In the last decades, especially the grassland species have been heavily exposed to an intensified exploitation of grasslands, which is why the populations of these species is shrinking. This is why we try our best to make sure that viewing the rarest species is organised in small groups under professional guidance. All orchid species in Slovenia are protected. Dry grasslands as habitats are additionally “protected” by the Habitats Directive, which was the basis for the inclusion of meadows on the hills of Vetrnik, Oslica and Bohor into the Natura 2000 ecological network.

The greatest number of blossoming orchids can be seen from the end of April to the end of June. However, in the forests, the blossoming season continues to the end of July (the Hellebores genus).

Special botanical features

Due to the various geographical characteristics, species typical of alpine, Panonic and submediterranean areas can be found in the Kozjansko region in addition to the common continental species. Many of those species reach the extreme limits of their habitat. Below, some of the species are described in more detail.

Dark purple Hellebore (Helleborus atrorubens)

This is a hellebore species that can only be found in the area comprising Kozjansko, Lower Carniola, Bela Krajina and part of Croatia. Its deep purple (scarlet) blossoms can mostly be seen on the edges of the forest and often also in the forests or meadows. If the species grows where there are green-blossomed fragrant hellebores (H. odorus), cross-fertilization may occur. Like all hellebores, this species is also protected (transplanting and collecting seeds is forbidden).

Blagay daphne (Daphne blagayana)

Most of the locals refer to this species as the royal flower. Along with the edelweiss, it was the first plant to be protected on Slovenian soil (in 1898). It was discovered on the Grmada hill by Polhov Gradec and was named after Count Blagaj. This low evergreen shrub shows all its beauty in April when it blossoms. It grows on steep and shady forested gorges in several places in Kozjansko.

Winter aconite (Erantis hyemalis)

One of the most early blooming plants with first blossoms appearing right after the snow melts away. It can even withstand snow once it has formed its blossoms. It grows on the forest floor and also on forest edges in Podsreda and on Bohor hill. Usually the plant completely covers the ground, thus colouring the ground completely yellow. Since 2004 it has been a protected species. Seeds can be obtained from certain garden centres.

Narrow leaved sandwort (Moehringia bavarica)

Like all sandworts, the narrow leaved sandwort also grows in rocky walls. It forms mats around the crack, in which its permanent root is positioned. In the middle of April, snow-white blossoms develop. It can be found above the Orešje village and on dolomite solitary rocks of the Kopitnik hill. It is mainly endangered due to physical destruction caused by climbing.

Mountain cowslip (Primula auricula)

As the name itself indicates, this is a mountain species and is one of the symbols of alpine flora. In the hills of the Kozjansko region, it can be found on shady dolomite walls, where it had already grown in the period of ice ages (a glacial relict). The edges of its tough, leathery leaves are coloured white due to limestone secreted by the plant. It normally blossoms in April, but this depends on the duration of wintery conditions. Since the species is protected, it is prohibited to transplant it into artificial rock gardens.

Fringed pink (Dianthus monspessulanus)

Of all carnations, this species features the most magnificent blossoms. At first sight it appears as if its floral leaves had been ripped by a strong wind. On dry, grassy and sun-exposed areas of Vetrnik, Oslica, and Bohor hills, as well as in rocky walls of the Zagaj gorge, the plants blossom in July. The blossoms can be either pinky or completely white. With the exception of sweet William, all the other species are protected in Slovenia.

Water caltrop (Trapa natans)

Water caltrop is an annual water plant. It has no real root, so the plant is fixed into muddy grounds by means of auxiliary roots, while roots growing from parts above the ground are green and used in the process of photosynthesis. Leaves, which develop above the water surface, have the shape of a diamond with serrated edges. The bubble-like inflated stems float on the water’s surface. The fruit appears as an irregular shaped light brown nut with four horned growths, a hard shell and a single, large white seed. Once the nut is ripe, it falls to the ground and a new plant develops from it. It is distributed by water birds. The seeds have a pleasant sweet taste, which are reminiscent of walnuts or chestnuts. Water caltrop was widely used as a food as early as in the early stone age.

Butcher’s-broom (Ruscus aculeatus)

This is an evergreen perennial plant, growing up to 1m in height with modified leaf-like shoots (phylloclades). The stem is split into forks and forms a bushy shape. Leaf-like shoots, up to 3.5cm long, are egg-shaped, leathery and have a spikey edge. Tiny green and white blossoms grow from the very centre of these leaves. A bright red berry develops from the blossoms. Due to excessive use for decorative purposes, the species is rare and has consequently been protected.

Grass-leaved iris (Iris graminea)

This is the smallest of all “wild” irises. It grows on thermophilic ground with little soil, usually on forest edges. Flowers, which appear in May, can hardly be seen due to its long, sabre-shaped leaves. In Slovenia, all iris species are protected.

Birds in meadow orchards

Thanks to old trees, the absence of spraying and non-intensive use of land, meadow orchards are an important habitat for many bird species.

Eurasian wryneck (Jynx torquila)

The smallest woodpecker species in Slovenia. It is also the only migratory species. It requires suitable trees with holes or anthills for its successful nesting. The bird raises its offspring in existing cavities (or nesting boxes) that are only present in older and thicker fruit trees. The offspring mainly feed on ants. The Eurasian wryneck is one of the few species known for singing abilities in both the males and females.

Common redstart (Phoenicurus phoenicurus)

In April, one of the most beautiful birds in Slovenia returns from warm regions of Africa. It nests in tree cavities, as well as in suitable nesting boxes. The common redstart has become highly endangered due to destruction of extensive orchards with tall trees, use of phytopharmaceutical agents on fruit trees (poisoning of insects that the common redstarts feed on), and the degradation of the African environment where they spend the winter. In recent decades, the common redstart has become extinct in several parts of Slovenia.

European scops owl (Otus scops)

This owl species (commonly known as “small owl”) prefers a moderate climate, which is why the majority of European population lives in the Mediterranean. This is a migratory bird, which prefers rural areas – meadow orchards and gardens, while it avoids thick forests. It builds its nest in tree cavities, holes in walls, as well as in nesting boxes. It feeds on larger insects, such as grasshoppers, beetles, moths, earthworms, as well as small vertebrate animal, such as mice, frogs, small birds and lizards. It is endangered by the lack of appropriate nesting spots and the general chemical pollution of the environment.

European goldfinch (Carduelis carduelis)

This is a non-migratory bird, which lives in orchards and open areas with individual trees and bushes, parks and gardens. It builds its nests on the ends of branches of deciduous trees, at least 2 metres above the ground. It feeds on insects, thistle seeds, grass and crop plants, as well as tiny tree seeds and buds. In the winter, it eats sunflower and millet seeds from birdfeeders.

Red-backed shrike (Lanius collurio)

Like other representatives of shrikes, the red-backed shrike is a carnivorous bird, which is also shown by its strong beak with a curved end. It mainly feeds on larger insects, as well as vertebrate animals, e.g. smaller birds, reptiles and rodents. This bird inhabits cultural landscapes – in areas where meadows are interrupted by cultivated land and low bushes. It builds its nest in thorny bushes (such as hawthorn or dog rose), using twigs, which they then cover with grass. It has often been reported that it sticks its prey on thorns. However, such behaviour is quite rare. Populations of this species are shrinking in most parts of Europe, which is why efforts are being made to protect it in Natura 2000 areas. The red-backed shrike is a migratory bird, which flies to Africa in the autumn and usually returns in May.

Forest birds

Extensive forests are of key importance for the survival of numerous bird species living in forests. Some of these species are present in various kinds of forests (finch), while others require special types of forests (goldcrest). Many forest birds are migratory birds, while species mostly feeding on seeds do not migrate.

Finch (Fringilla coelebs)

It is one of the most widespread species in the forests of the Kozjansko region. Its round, well-built nest is made of moss, lichen and blades of grass. The bird uses fur and the soft parts of plants in its nest. It builds its nest on forked branches near the trunk. It feeds on various insects, beechnuts, tiny tree seeds and berries. In the winter, it can also be spotted around birdfeeders.

Blue tit (Cyanistes caeruleus)

This is a small, adorable and lively species of tit, which behaves as if everything around it is under its control. It is very attracted to winter birdfeeders. Its nesting spots are tree cavities, wall holes, and nesting boxes. Blue tits often pick unusual nesting places. Of all the songbirds, blue tits have the largest brood. Often, there are 15 eggs in a single brood.

Tawny owl (Strix aluco)

The most common and well-known representative of the owl family in Slovenia. It is assumed that it has the best night vision of all birds. It appears in two colour variants – light grey and, rarely, multi-coloured (red-brown). It lives in deciduous and mixed forests, forest edges, fields and also human settlements. In feeds at night by hunting mice, voles, shrews, dormice, frogs, smaller songbirds, larger insects, and earthworms. In the old days, it was embarrassing for a rural boy not to be able to imitate this bird’s sounds.

Middle spotted woodpecker (Dendrocopos medius)

It primarily lives in oak forests. It nests in old and dying trees – its beak is not as strong as the beaks of other woodpeckers, which is why it only can make holes in rotten wood. It feeds on insects and in the winter also on seeds. Due to the lack of nesting space it has become very rare and is considered an endangered species on a European scale. The middle spotted woodpecker is also one of the Natura 2000 species (Natura 2000 classification species of the Dobrova–Jovsi SPA area).

Collared flycatcher (Ficedula albicollis)

This is a migratory bird, which spends its winters in Africa. It returns to our forests in the second half of April. It is known for its typical hunting pattern – it flies from its perch to catch the insect, and then returns to its primary position. The collared flycatcher can be found in light deciduous forests with old trees, as well as in orchards and groves. It is endangered due to the lack of appropriate natural nesting sites. Nesting boxes should be equipped with a 32mm-wide entrance opening, since other suitable nesting sites are already taken by other secondary woodpeckers by the time the collared flycatcher returns from Africa.

European bee-eater – nesting site in Bizeljsko

Since the 1980s, the Župjek pri Bizeljskem quarry is the home of the European bee-eater colony (Merops apiaster). The number of nesting bird couples varies, but is usually between 10 and 20. In the first days of May, the European bee-eater returns from places where it spends the winter. It builds its nest in a passage of a vertical sandy wall – almost 1 meter deep. European bee-eaters are excellent fliers and mostly feed on flying insects, especially dragonflies, bumblebees, and bees. The best time for spotting them is the beginning of June, when breeding is almost finished and adult birds often fly to and from their homes, and sometimes the young birds can be seen waiting right by the entrance.

There is an observatory available for bird-watching as the presence of people by the wall disturbs the birds may cause adult birds to stop feeding their offspring. There is an information board next to the observatory.


There are more than 3600 butterfly species living in Slovenia (180 of these are Rhopalocera butterflies), more than 1100 of which have already been spotted in the Kozjansko region. Thanks to the geographical characteristics of the area, wide-spread species can be found here, as well as species that normally live in either warmer Mediterranean or colder alpine regions. Due to a quite high level of conservation of the natural environment, and the presence of meadow orchards and meadows, several species can be found here that are otherwise rare. Every year, several events are hosted to observe night butterflies, and you can also participate in European nights for the observation of night butterflies. Visitors can get to know the butterflies on guided tours through dry grasslands or by means of image-supported lectures.

Peacock butterfly (Inachis io)

It has brown-red striped wings with black, yellow, and blue spots and one “eye” on each wing. The bottom side is coloured in dark brown shades. It spends the winter like all other butterflies do – it hides in garden sheds, cellars, and attics, where it goes numb and waits for warmer days. It can be found on forested river banks, wet grasslands and pastures, as well as in areas where humans are always present and where there is an abundance of stinging nettles (food for caterpillars). Female lays eggs on the nettle (Urtica sp.). Black caterpillars with white spots hatch from the eggs. They live in groups of tens of caterpillars. Adult butterflies feed on tree sap and nectar, while caterpillars feed on nettle leaves.

Common yellow swallowtail (Papilio machaon)

It lives in larger parts of Europe and Asia, as well as in North America. The base colour on the wings is sulphur yellow. The wings are scattered with black spots, while there is a brown-red “eye” on the inner edge of both back wings. On the rear part of the wings, the butterfly has a short tail – hence its name. The common yellow swallowtail is a fast flier and can best be seen floating above blossoms and sipping nectar. It is the largest Rhopalocera butterfly in Slovenia. The caterpillar is of intense green colour with contrasting black and orange spots. Its warning colour is used as a signal to possible predators by secreting a foul-smelling substance from the glands located behind its head.

Southern festoon (Zerynthia polyxena)

The southern festoon is a middle-sized butterfly from the swallowtail family. Caterpillars feed on different species of the birthwort genus (Aristolochia). Adult butterflies tend to spend most of the time in light deciduous forests and on forest edges from April to June, whereby this includes one prolonged generation. They are rare and thus protected on a European scale (it is a species for which Nature 2000 must be defined).

Emperor moth (Saturnia pavonia)

Its wing span is up to 80mm. The emperor moth is a grey colour with big dark “eyes” on the wings. Males are smaller (up to 60mm) and have orange-red back wings with one “eye” on each of them. This species can be seen from April to June. Males also fly during the day, while females mostly fly in the night. Males can detect the presence of a female several kilometers away using their large brushy tentacles.

Japanese oak silkmoth (Antheraea yamamai)

It originally comes from Japan. In Europe, it first appeared in the village of Veliki Slatnik under the hilly Gorjanci area in the Lower Carniola region. Jan Mach, an entrepreneur from the village Veliki Slatnik near the hilly Gorjanci region tried to breed the caterpillars on oak trees in 1866 in order to produce shantung silk. His attempts were successful. However, he was not careful enough and some pupae were left in nature. In the following century, the species gradually spread into neighbouring areas and other European countries. Adult representatives of this species do not consume food, since their only role is reproduction. For the purpose of finding females, males use large feather-shaped antennae, which allows them to successfully detect females over long distances. Females usually carry a lot of eggs, which is why it is quite difficult for them to fly. Since adult animals do not consume food, they use supplies from before, which last for 3 to 4 days.

Necklace veneer (Euchromius ocellea)

The necklace veneer (Euchromius ocellea) is a species indigenous to subtropical and tropical parts of Africa, and which migrates to Europe each year. In September 2012, it was spotted twice in the park. This was the first spotting of this butterfly species in Slovenia. It is hard to believe that butterflies of this species, which only have wing span of 16–25mm, can fly such long distances.


At the moment, 350,000 species of beetles from around the world have been recorded (Europe: 8000, Slovenia: 6000 species), which is approximately 40 per cent of all insect species and a quarter of all animal species recorded. The first publication systematically dealing with beetles in Slovenia was written by Scopoli (Entomologia carniolica, 1763). Coleopterology in Slovenia increasingly developed with the description of the Leptodirus beetle, the first cave beetle in the world, which was discovered by Luka Čeč in 1831 in the Postojna cave. Undoubtedly, two of the most well-known beetle species are the Rosalia longicorn (Rosalia alpina), one of the first protected and one of the biggest beetles in Slovenia, and the stag beetle (Lucanus cervus), the biggest beetle in Europe.

Stag beetle (Lucanus cervus)

It is the largest European beetle with adult species reaching a length of 25 to 85mm. It was named after the enormous mandibles of males that resemble stag horns (in Latin cervus = stag). They are used for ritualized combat for both territory and females. They are active at dusk in summer months when the males fly around making a low-pitched buzzing noise looking for females. They take four years to mature. The larvae drill through the rotten wood of dead and dying trees (oak). Afterwards, they pupate in the ground for three months before emerging as adult animals. Adults feed on plant juices, which they get by cutting into bark using their mandibles. Due to the excessive removal of dry wood from forests, the species has become rare – which is why it is protected by Slovenian and European legislation (a Natura 2000 species).

Rosalia longicorn (Rosalia alpina)

It is a representative of the longhorn beetles and measures from 15 to 38mm in length. Its antennae are the same length as the body in females, while being much longer in males. The elytra are flat, with a blue-greyish colour and various black spots, including a distinctive patch in the chest area. The antennae and legs are the same colour as its other body parts. This types of colouration acts as good camouflage in the beetle’s habitat, i.e. beech forests at 600–1,200m above sea level. The development of the larvae, which takes several years is dependent on dry (dead) beech wood. The drying of logs and beech wood in the forest over the summer is disastrous for the species since the females lay their eggs in this wood. Due to the excessive removal of dry wood from forests, the species has become rare – which is why it is protected by Slovenian and European legislation (a Natura 2000 species).

Capricorn beetle (Cerambyx scopolii)

It is also known as the small oak Capricorn beetle. The development of its larvae primarily depends on oak trees, but also willow and chestnut trees. Adults can often be found during the day on flowering plants, especially on the flowering black-berried elderberry.

Carabus gigas (Procerus gigas)

The damp forest environment is perfect for the Carabus gigas beetle, which also moves around during the day, especially in rainy or cloudy conditions. Quite often it can be observed indulging in the remains of a squashed snail in the middle of a path, not minding what is going on around it. However, do not disturb the large and otherwise seemingly peaceful beetle too much. Like all ground beetles, the Carabus gigas has a habit of lifting its sternum when in danger and spraying a foul-smelling and caustic fluid right into the offender’s eye. (AL Vrezec, Planinski vestnik, 2011, Vol. 9)


Bats are nocturnal animals and the only mammal species capable of active flight. Their front extremities have evolved into wings. There is a special membrane between its extended finger and arm bones as well as its body and rear legs, crisscrossed by elastic fibres and capillaries. In our region, bats feed on insects and other arthropods. Their excrements – guano – is considered to be an extremely high-quality fertiliser worldwide since it contains a lot of nitrogen and phosphorus, thus acting as a nematicide and fungicide. Bats see exceptionally well. At night, they have no problem catching even the smallest of insects. They have well-developed eyes and good vision, but they are not the main sensory organ for seeing. They have developed a special system that works like sonar. They only emit inaudible ultrasonic pulses (in a frequency range above 20,000Hz) and listen to the echoes as they hit obstacles, thus creating an image of the surveyed environment and the position of their prey – this process is known as echolocation. That way, horseshoe bats can detect even threads as thin as just 0.05mm! So far, 1,116 bat species (Chiroptera) have been discovered worldwide, which represents a quarter of all mammals in the world. In Europe, there are only examples of small bats from 32 species, whereas in Slovenia alone, 30 species have been discovered (reference:

Usually, the main reason for people killing or poisoning bats is a prejudice against them. Try to think of bats as your neighbours. They eat a lot of insects that would otherwise be buzzing around your bedroom or munching on your vegetables in the garden. It is also prohibited by law to kill or disturb bats. Bats are among the most endangered animal groups in Slovenia, Europe and elsewhere in the world. Often, they are endangered as a result of human ignorance. By familiarising ourselves with the habits of bats, we can protect them.

The biggest danger to bats are people because they interfere in their living environment, e.g. by destroying their shelters when renovating buildings, preventing their access to buildings by installing nets on openings, with the unsuitable placement of bars on the entrances of caves, disturbances in their shelters (e.g. cave tourism), illuminating the passages in the habitats, and general light pollution, destruction of forests, or through changes of forest management (removal of old hollow trees, destruction of their feeding areas), destruction of crucial linear elements in nature (hedgerows, hedges, isolated trees, etc.), excessive use of pesticides on agricultural surfaces, application of wood preservation agents that are poisonous to mammals in bat sheltering areas.

Sometimes, out of fear and prejudice as well as due to dirt from bat excrement (guano), or sadly out of pure cruelty, people kill or poison bats near their homes on purpose.


Today, there are around 6,000 species of amphibians in the world. The study of amphibians, together with the study of reptiles, is called herpetology. The life cycle of most amphibians starts with an aquatic larva that breathes through gills all the way to the adult land animal that breaths with lungs. Amphibians regulate the number of insects, snails, spiders and earthworms since they feed on them. Amphibians are mostly endangered by the destruction of their habitat (drying out and filling up of wetlands), water pollution, the use of chemicals (e.g. pesticides), environmental changes, and the disruptions to migratory routes over roads (amphibians get run over by cars). Recently, experts in Europe and worldwide have noticed that amphibians are dying due to a viral disease caused by a ranaviruses and due to a fungal disease called chytridiomycosis. Because they are highly endangered, all our amphibians are protected. It is prohibited to kill or poison them or to destroy their living environment.

In the Kozjansko park, we have helped amphibians migrate to their spawning grounds by the Trebče pond every spring since 1999. On both sides of the road, we place a barrier that prevents them from crossing the road. Twice every day (in the morning and in the evening), we manually carry them across the road. In this way, we transferred almost 6,000 amphibians in 2014. The most frequent species is the common toad, but we also deal with the common frog and the agile frog (two species of brown frogs), as well as the smooth newt and the alpine newt. Every year, the campaign receives help from local schools and interested individuals.

Amphibians (PDF 1) Amphibians (PDF 2)