Jezevčí vrch (665 metres above sea level and previously known as Jílový vrch, Limberg and Dachsberg) dominates the south-eastern part of the Lužické hory mountain range and lies in the Liberecký kraj – Liberec Region. The hill is a relatively extensive phonolite neck with bodies of basalt. The lower elevations are built of Turonian sands and sandstones. Jezevčí vrch belongs to the Ralská pahorkatina hilly land geomorphological region and to the Cvikovská pahorkatina district. The Jezevčí vrch block is separated from the main Lužické hory mountain range (Hvozd and Sokol bocks) by the Heřmanice Fault line.
The Czechoslovak Ministry of Culture and Information declared Jezevčí vrch a State Nature Reserve in 1967 on an area of 79.16 ha and the area was redeclared as an NNR in 1992. The main subject of the protection is the typically preserved mixed forest with the character of herb-rich beechwoods and talus and ravine forest with a rich herb layer on the phonolite basement with the occurrence of many protected animal and plant species. The borders of the reserve are marked as red stripes on the trees and the state emblem on access paths. To visit Jezevčí vrch NNR you should follow the yellow marked tourist trail to the east from the summit. The whole peak is covered with tall forest stands and does not offer views over the surrounding countryside.
On the slopes below the summit the most extensive forest type in the reserve – the herb-rich beechwoods can be found. The tree layer is dominated by beech (Fagus sylvatica) and includes other tree species such as sycamore, ash, hornbeam, wych elm, Norway spruce and more rarely silver fir. The rich herb layer includes typical species for herb-rich beechwoods, including dog’s mercury (Mercurialis perennis), coralroot (Dentaria bulbifera), nine-leaved toothwort (Dentaria enneaphyllos), woodruff (Galium odoratum), herb Paris (Paris quadrifolia) and the extensive and significant growths of perennial honesty (Lunaria rediviva). The carpets of perennial honesty here in the NNR are among the largest in the Lužické hory mountain range.
Wych elm (Ulmus glabra) which is a characteristic tree of the talus and ravine forests is currently represented in the tree species composition of the Lužické hory mountain at only 0.01%. In suitable conditions wych elm forms mixed stands with beech, sycamore, ash and lime. This semi-shaded, frost-resistant tree requires slightly damp humus and mineral-rich soils on which it can grow to 40 metres in height and lives for 300-500 years. The wych elm also has high demands on air moisture content and has characteristic rough leaves with a hairy underside and saw tooth-shaped edges.
In the first half of the 20th century elms were affected by a serious disease – the so-called Dutch elm disease – which spread widely in Holland after the First World War and from there it spread all over Europe. The disease is caused by the microscopic fungus Ophiostoma ulmi which fills up the water-carrying tissue in the trees and prevents nutrients from being carried up the tree. The elms dry out from the crown and tips of the branches. The fungus is mostly carried by wood-borers and bark beetles. The most significant carrier of Dutch elm disease is the smaller European elm bark beetle (Scolytus multistriatus) which burrows into the bark of the elm.
Wych elm is more resistant to Dutch elm disease than the other elm species, but nevertheless it is still a rarity in the current Lužické hory mountain forest stands.
Of the 162 invertebrate species which have been recorded in the Jezevčí vrch NNR, the majority belong to the ground beetles (Carabidae) and rove beetles (Staphylinidae), although other groups have not been researched in detail. A total of 78 vertebrate species which are typical representatives of the Central European deciduous forests have also been recorded here, of which 4 are amphibians, 4 are reptiles, 48 are birds and 22 are mammals.
The rare ground beetle Carabus irregularis and the ground beetle Cychrus attentautas are examples of relict species which indicate that the forest stands are of natural origin, as these beetles are closely bound to native mixed forests.
The sandstone rocks on the Jezevčí vrch slopes are a traditional nesting site for eagle owls (Bubo bubo) – which are the largest owl species in the Czech Republic. The nest is often in a rock cavity, cleft or directly on the bare ground although eagle owls often use the old nests built by other birds (large birds of prey, herons, black storks). At the end of March or in April the female lays 2 – 4 eggs, on which she sits for around 35 days and during this time the male brings her food. The young owlets stay in the nest for about 6 weeks. The main food for eagle owls are small to medium-sized rodents but especially voles.
Birds of prey which can be found in the reserve are the goshawk (Accipiter gentilis), hobby (Falco subbuteo), buzzard (Buteo buteo) and sparrow hawk (Accipiter nisus). Black storks (Ciconia nigra) have been observedseveral timesas they flew over the reserve.
Greater, middle and lesser spotted woodpeckers ((Dendrocopus major, Dendrocopus medius and Dendrocopus minor) and the black woodpecker (Dryocopus martius) are birds of the woodpecker family with strong beaks which they use to hollow out nesting holes in the trees and to extract the larvae of woodborers and bark beetles on which they feed. Two kinds of pigeons nest in the reserve – wood pigeon (Columba palumbus) and stock dove (Columba oenas). The raven (Corvus corax) is a regular visitor here and has become more common in the Lužické hory mountains in recent years. Here we can also observe strong populations of cuckoo (Cuculus canorus) and jay (Garrulus glandarius). Notable songbirds which occur in the reserve are the ring ouzel (Turdus torquatus) and spotted flycatcher (Muscicapa striata).
Small predators which live in the forests are the beech marten (Martes foina), stoat (Mustela erminea), weasel (Mustela nivalis), western polecat (Mustela putorius) and badger (Meles meles). Small rodents which live in the undergrowth are the yellow-necked mouse (Apodemus flavicollis), striped field mouse (Apodemus agrarius) and bank vole (Clethrionomus glareolus) while red squirrels (Sciurus vulgaris) can be seen high in the trees.
The occurrence of the thermophyte agile frog (Rana dalmatina) in Jezevčí vrch NNR makes this its only known locality in the Lužické hory mountains. These frogs have obviously spread here from their regular occurrence in warmer parts of the Česká Lípa district.