Velebit Leech (Croatobranchus mestrovi)
Velebit leech, a species endemic to Northern Velebit, was discovered in Lukina pit in 1992 and is the most significant animal discovery in the Park. It is completely adapted to the life in the subterranean, and has so far been discovered in only four deep pit caves in the Park. It is mostly found at depths below 500 meters, usually clinging to the walls in a thin layer of flowing water or in hollows with running water. It has a flat body, about 25 - 45 millimeters long and 10 millimeters wide, with ten pairs of lateral gill-like processes characteristic of this species, most probably serving as respiratory organs. The leech is milky white to yellowish in color, it has no eyes and is bisexual. It has a small sucker at the front of the body, and a larger one at the back. It is often seen clinging to the wall with the help of its back sucker, the front facing a water stream, while twisting its body as if trying to catch something. Very little is still known about the life of Velebit leech.

Apollo (Parnassius apollo)
A member of the swallowtail family, Apollo is one of our most beautiful butterflies. This butterfly species inhabits very restricted small areas, mountain pastures and rocky highland habitats at altitudes ranging between 1000 and 2000 meters. Its most distinctive features are the red, black-edged eye-spots with a white centre on its wings. An interesting fact is that each Apollo has different shaped eye-spots, similar to fingerprints in humans. The wings are covered with scales and partly with white hairs. It is believed that the Slovene mountaineer Alojz Knafelc, the inventor of the Knafelc trail blaze, was inspired by the Apollo butterfly in creating this mark. In Croatia, Apollo is strictly protected and is included in the Red List of Threatened Butterflies of Croatia under the Vulnerable category.

Clouded Apollo (Parnassius mnemosynae)
Clouded Apollo is similar to Apollo, but lacks the red and white spots on the wings, which are partly transparent. It is more common than Apollo, and is usually found at altitudes above 1000 meters, and only rarely in dry and hot habitats close to the sea level. In Croatia, it is a strictly protected species and is included in the Red List of Threatened Butterflies of Croatia under the Least Concern category.

Hummingbird Hawk Moth (Macroglossum stellatarum)
This moth is a member of the hawk moth family. It normally flies during the day until dusk, and rests on the rocks during the night. It is a very good, agile and persistent flyer. It sucks the nectar with its long proboscis never sitting on the flower, but hovering and fluttering above it like a hummingbird. Flitting from flower to flower, it can visit as many as a hundred flowers in 4-5 minutes, transporting pollen with its proboscis.

Olive Bee Hawk Moth (Hemaris croatica)
Described for the first time in Karlovac, this hawk moth is resident in southeast Europe and parts of southwest Asia. It has a beautiful light olive-green body with a red second pair of wings. Its way of life is similar to that of hummingbird hawk moth and is commonly found on the south-lying slopes of mountain ranges. It is incorporated in the emblem of the Croatian Entomological Society.

Common Yellow Swallowtail (Papilio machaon)
This large-sized butterfly has a wingspan of 75 millimeters. Lovely markings and hind wings with protruding dark tails make this species one of the most beautiful butterflies. It is found in grasslands and rocky grounds on calcareous base. In mountain areas it can be found up to altitudes of 1500 meters. It is classified as a strictly protected species.

Scarce Swallowtail (Ipchiclides podalirius)
A large and easily recognized diurnal butterfly, it is similar to the common yellow swallowtail. Somewhat less colorful, it has vertical black stripes on the wings and a longer tail on the hind wings. It usually flutters around flowers, bushes and ponds.

Alpine Newt (Mesotriton alpestris)
Alpine Newt resides in wet woodlands in mountain and alpine regions and is more commonly found in and near water than in terrestrial habitats. Alpine Newts are especially interesting at mating time, when the males change color and appearance and try to court the female with their dance. During the breeding season, the males have a colorful crest on the back and tail. Alpine Newt is a protected species.

Salamander (Salamandra salamandra)
Salamander lives in wet terrestrial habitats, but lays its offspring in water, where the larvae live until they reach adulthood. It is mostly active in the evening or at night, and in rainy weather can also be seen during the day. It feeds on earthworms, snails, insects and spiders, while the larvae feed on small aquatic invertebrates. Adult salamanders have poisonous glands along the entire body. The poison they secrete irritates the eyes and mouth of the attacker, which is why salamanders are avoided by most animals. Adding to this is their conspicuous black and yellow color which warns the predator that they are poisonous and not tasty. The yellow spots on each specimen are unique in their pattern, size and shape. Salamander is a protected species.

Common Toad (Bufo bufo)
Mostly active at night, the Common Toad comes out at dusk, and during the day hides under stones, in rock crevices and in holes in the ground where it also hibernates. It feeds exclusively on insects, larvae, spiders, snails and other invertebrates catching the prey with its sticky tongue. As a protection against predators, it has glands that secrete an irritating substance through the skin, which acts as a deterrent to most predators. Common Toad is a protected species.

Horvath’s Rock Lizard (Iberolacerta horvathi)
Native to the Velebit mountain, Horvath’s Rock Lizard is a petrophilic species inhabiting rocks, cliffs and other stony grounds. It has a very restricted habitat and is also found in east Alps and the northern regions of the Dinarides. It is present in high mountains in areas up to the upper boundary of forest vegetation (up to 1600 m above sea level). In Velebit, it was first identified around Mrkvište and Veliki Alan by Miroslav Hirtz in 1908. Horvath’s Rock Lizard is a strictly protected species.

European Ratsnake (Zamenis situla)
European Ratsnake is among the most beautiful non-venomous snakes in Croatia. It is found on the coast-facing side of the Park in dry, rocky habitats overgrown with shrubs. It moves relatively fast and is active during the day, and sometimes also at dusk. Young snakes feed on insects, while adults feed on rodents and small reptiles. European Ratsnakes suffocate their prey by constriction. They are often mistaken for venomous snakes because of their colorful body and people often kill them out of fear and ignorance. European Ratsnake was once very common, but is today much harder to encounter in nature. It is a strictly protected species and is listed in the Red List of Reptiles in Croatia under the Data Deficient category..

Aesculapian Snake (Zamenis longissimus)
This up to 2-meter long, non-venomous, slander snake is among the longest snakes in Europe. Adults can be brownish, grayish-green, sometimes almost black, with white-edged scales, especially at mid body. The belly is yellow to whitish. Aesculapian Snake can move very fast and is agile in climbing trees and bushes. It feeds on mice, voles, sometimes squirrels, lizards and smaller birds. It suffocates its prey by constriction. The name of this snake refers to the Greek god of healing Aesculapius (lat. Aesculape). Entwined around Aesculapius's rod, this snake is the symbol of medicine and pharmacy. In Croatia, Aesculapian Snake is a strictly protected species.

Nose-Horned Viper (Vipera ammodytes)
Nose-Horned Viper is Europe's largest venomous snake. It normally resides in dry, rocky areas covered with low shrubs and trees, and avoids wet habitats. Its distinctive characteristics are its relatively short, heavily built body, its slightly triangular head, a dark zigzag line running along the back and a single horn on the snout. Males are usually grey and females are brown. Nose-Horned Viper locates its prey, primarily rodents, birds and lizards, by smell and mostly lies in wait for the prey. It normally hunts at night, and spends the day curled up sleeping and digesting the food. The prey is first killed by venom and then swallowed. Nose-Horned Viper hibernates in colder regions. In Croatia it is a protected species.

Woodpeckers
Woodpeckers are an extremely important group of birds in many ecosystems. During the day they hop from one tree to the next in search of food which they find on or underneath the tree bark. They are able to do so owing to their short and strong legs, with their hard and stiff tail feathers serving as support. To declare their territory, they drum on trees, selecting for this purpose trees with good resonance. Woodpeckers nestle and spend the night in hollows of trees. They dig out holes with their powerful, chisel-shaped beak in places where the tree has become soft due to decay. They need about 10 to 25 days to drill a hole. Since they mostly nestle in decaying older trees or even in dead upright trees, woodpeckers do no damage to commercially viable parts of trees. Woodpecker holes are extremely important for the survival of a large number of other bird species, mammals (especially bats) and other animals which use old woodpecker holes for nesting and shelter. This is why the woodpeckers are considered key species in the ecosystem, being species that, though not necessarily present in large number, have an exceptionally important impact on the structure and functioning of ecosystems. The Park is home to a number of woodpecker species: Three-toed Woodpecker (Picoides tridactylus), White-backed Woodpecker (Dendrocopos leucotos), Lesser Spotted Woodpecker (Dendrocopos minor), Great Spotted Woodpecker (Dendrocopos major), Grey-headed Woodpecker (Picus canus) and Black Woodpecker (Dryocopus martius). They are strictly protected and all, except the Great Spotted Woodpecker and the Black Woodpecker, are included in the Red List of Threatened Birds of Croatia.

Capercaillie (Tetrao urogallus)
The largest wood grouse in Croatia, Capercaillie resides at altitudes above 1000 meters in high mountain forests of beech, fir and spruce. In winter it feeds on beech buds and fir and spruce shoots and needles, and in summer eats seeds, forest fruits, insects, caterpillars and snails. Due to habitat disturbance, the population of Capercaillie has significantly decreased in the past decades. Its greatest enemy is man, but is also threatened by predators such as the fox, the European pine marten, the wild boar, the owl, the eagle and the buzzard. In Croatia, capercaillie is today found only in the mountain regions of Lika, Gorski Kotar, and the north and central Velebit. The Northern Velebit National Park is one of the few refuges for these rare birds in Croatia. They can mostly be encountered on forest paths where they collect stones or along mountain trails when forest fruits they feed on are in season. Capercaillie is a strictly protected species in Croatia and is included in the Red List of Threatened Birds of Croatia under the Endangered category.

Common Crossbill (Loxia curvirostra)
Common Crossbill inhabits fir and spruce forests in Velebit. The name Crossbill explains the unusual, strong and twisted beak with overlapping tips. It mainly feeds on conifer seeds, but may also eat beech and maple seeds. It hangs from branches or clings to the bark while feeding, holding the cone with both legs or pressing it against a branch. Crossbills insert their bill into the cone from the side, pry open the cone bract and extract the seed with their tongue. Common Crossbill is a strictly protected species.

Tengmalm's Owl (Aegolius funereus)
Tengmalm's owl is commonly found in fir, spruce and beech forests. It is not sociable and normally spends the time alone. Its prey are mostly smaller mammals, but it also eats insects and some smaller birds. It uses its acute hearing to hunt, and can track mice under shrubs and snow. The enemies of this bird are the European Pine Marten, Tawny Owl and Eurasian Eagle Owl. Tengmalm's Owl is a strictly protected species and is included in the Red List of Threatened Birds of Croatia under the Least Concern category.

Ural Owl (Strix uralensis)
In mixed beech and fir forest Ural owl is the most common owl species. It has quite a long tail and grayish-white feathers with wide dark brown streaking, which makes it look like a hawk when flying, hence its Croatian name (Jastrebača, jastreb = hawk). It nests in hollows in trees or old nests of other large birds. It is mostly active at dusk or dawn, but often also during the day. The Ural Owl feeds on small rodents, but may also hunt smaller birds and other mammals. In Croatia, Ural Owl is a strictly protected, species and is included in the Red List of Threatened Birds of Croatia under the Least Concern category.

Brown Bear (Ursus arctos)
The bear is a big and powerful animal with a highly developed sense of smell and hearing, but considerably less developed eyesight. It weighs between 100 - 150 kilograms, with some specimens reaching a weight of up to 300 kilograms. Although having a digestive system typical of carnivores, the bear is not picky when it comes to food, and will eat whatever is on offer: from fruits and vegetables, forest herbs, grubs and insects to carcasses. Illegal rubbish dumps are particularly dangerous for both people and bears, because the food remains attract the bears which, by feeding on rubbish dumps, start to lose their innate fear of humans becoming a danger to man if encountered. The brown bear is a protected species in Croatia and is hunted outside protected areas, while on European level it is a strictly protected species.

Grey Wolf (Canis lupus)
In the past wolves were present throughout the Croatian territory. In 1894, they occurred in all Croatian counties, but from this point on their population started to dwindle, primarily in low-land continental regions. Wolves have been persecuted and killed for hundreds of years and have therefore withdrawn deep into the forest, into remote and impassable areas. The wolf is a carnivore and its main prey includes the roe deer, red deer, wild boar and smaller mammals. Wolves also hunt emaciated, sick and famished animals or cubs positively affecting the health of the prey population and contributing to the stability of the entire ecosystem. In Croatia, the wolf primarily occurs in larger forests of mountainous and alpine regions. In the wider area of north Velebit there is a wolf pack present whose territory also includes the Northern Velebit National Park. The main reasons why wolves are today endangered are illegal hunting, traffic accidents and lack of natural habitat. The wolf is a strictly protected species and is included in the Red List of Threatened Mammals of Croatia under the Least Concern category.

Eurasian Lynx (Lynx lynx)
The Lynx was extirpated in Croatia at the beginning of the 20th century. The extant lynx population is the result of repopulation of lynx in Slovenia in 1973, with the species spreading to Croatia already the following year. Today, lynxes permanently inhabit the areas of Gorski Kotar and Lika. The lynx is a territorial animal and is usually solitary, especially during the mating season. It generally feeds on roe deer, red deer, chamois, hare and larger rodents. The lynx primarily hunts animals that have the largest population in its territory and are the easiest to catch. It hunts like a cat, stalking and jumping its prey from the ground, and not from a tree, as usually believed. It can catch a prey three to four times larger than itself and feeds on it for a couple of days. The lynx is the least well researched large carnivore, being a very secretive animal that is very difficult to spot. The lynx is a strictly protected species and is included in the Red List of Threatened Mammals of Croatia under the Least Concern category.

Chamois (Rupicapra rupicapra)
The chamois was reintroduced to the mount Velebit thirty years ago and can now be encountered on mountain tops in the National Park. It inhabits the highest mountain regions with pastures and rocky terrain, and descends to lower regions in winter. It is not picky when it comes to food and eats all types of mountain plants, and will also feed on leaves, buds and young tree shoots. The chamois has a body adapted to life in the most rugged terrains. Its strong and stoutly built body allows it great agility, flexibility and gracefulness of movement. It moves very nimbly and lightly on its relatively short and strong legs. Chamoises are exceedingly cautious and timid animals and if they sense a danger, they will alert the other members of the herd with a shrill „whistle“. They are socially well organized animals that live in the so-call female herds of goats with kids and young males up to three years of age, while adult males live solitary and join the herd only in the mating season. The chamois is a protected species in Croatia and is included in the Red List of Threatened Mammals of Croatia in the Least Concern category.

Balkan Snow Vole (Dinaromys bogdanovi)
Endemic to the Balkans area, this rodent is a living fossil (it belongs to an old genetic line and its closest relatives are fossil species). It inhabits karst rocky terrains, usually at higher altitudes. The Balkan Snow Vole reproduce slowly compared to other rodents – during its entire life the female produces only four young. It feeds on grass and other herbs. The species is very poorly researched. The Balkan Snow Vole is included in the Red List of Threatened Mammals of Croatia under the Data Deficient category and is strictly protected.

Edible Dormouse (Myoxus glis)
Edible dormouse is a rodent similar to squirrel and is the largest member of the dormouse family. It is a nocturnal animal, but can also be encountered during the day. In Velebit, it inhabits mountain, coastal and subalpine beech forests. It has small ears without tufts and big, bulging eyes. The dormouse has a voracious appetite and primarily feeds on beech nuts, acorns, hazels and forest fruits, but also eats insects, snails and eggs of young birds. It is very agile and easily climbs on flat surfaces, rocks and walls. It has no fear of humans and enters houses, attics and food storage rooms, especially in autumn when it collects energy reserves for the winter sleep. Edible dormouse hibernates almost 7 months, from September to the beginning of May, depending on weather conditions. It loses up to 50% of its body weight during hibernation. Its primary enemies are marten and wood owl. Edible dormouse is a strictly protected species and is included in the Red List of Threatened Mammals of Croatia under the Least Concern category.