Natural Heritage Gems

 The great wealth of natural, cultural and historical heritage is both a great gift and great responsibility! Experience our destination adorned not only by our 2Parks, but by the area in-between 2Parks which proudly boasts equally valuable heritage.

Dear visitors, this comparative view of our 2Parks natural heritage will help you better understand just how sensitive and fragile this systems are and why we need your support to protect them even better!

Natural Link Between 2Parks
Licka Pljesivica Massif

The magnificent massif of Licka Pljesivica was first described back in 1669. Endowed with virgin forests, alpine vegetation, fossil finds and rich fauna, Licka Pljesivica had attracted attention of many scientists and researchers in the past, including the Saxon king Friedrich August II (Poljak, 1996., p. 426).

Licka Pljesivica represents a natural link between our 2Parks. The Plitvice Lakes National Park, one of the most impressive karst landscapes in the world, is nestled between the mountain slopes of Mala Kapela and Mount Licka Pljesivica. In the nearby vicinity is the Una National Park, a prominent landscape in Europe with valuable karst formations and the hydrography of the River Una, sheltered by Mount  Licka Pljesivica and Osjecenica.

Licka Pljesivica is a valuable natural site, find more about it under Explore Local.

2Parks Phenomenon

Given the relatively small distance between our two national parks, 2Parks share many common elements, and certainly the most valuable element of the landscape and the common phenomenon is - water.

Plitvice Lakes NP Lake System

Although occupying only 1% of the Park’s overall area, the water represents the most valuable part of the landscape composed of a system of sixteen larger and a few smaller cascading lakes interlaced with rapids and waterfalls. The system is divided into Upper and Lower Lakes with numerous tributaries and have the characteristics of typical trout and mountain waters.

Highly valuable and impressive, the lake ecosystem requires intensive monitoring efforts by the Park's expert service!!


Upper Lakes consists of 12 lakes of which the two largest ones are Lakes Proscansko and Kozjak. Lakes are separated by unique and extremely sensitive tufa barriers that change in a continuous biodynamic cycle.

The Lower Lakes make the system of four lakes formed in a canyon. The highest cliffs in the canyon are 40 m high, and Lake Milanovac is surrounded by 20 m high cliffs. Breathtaking views awaits you at Lake Novakovic with 25 m high cascades.

Dear visitor, your role in protecting natural heritage is crucial!
Please carefully follow all rules and instructions!

Una NP WaterCourses

Despite the fact that Una is located in the most sensitive karst terrain with less-developed river network, this wider regional area with rivers Una, Unac and Krka is one of the richest aquatic ecosystem hotspots in the Dinarides. Una of amazing bright emerald green color has main characteristics of mountain waters with waterfalls, cascades and tufa formations with still well preserved hydromorphology. Una's tufa river bed is very long, 212 km, with beautiful natural attractions featuring barriers, islets, waterfalls, and other formations.

Una's Source 
The source is a powerful karst spring located in a magnificent 150 m-high canyon in the Republic of Croatia, municipality of Gračac, at an altitude of about 450 m on the northeastern side of the Stražbenica Hill. Una's powerful source, surrounded by limestone cliffs, has been protected as a hydrological monument of nature since 1968 (Bioportal, n.d.).

Tufa Formation

Although our regional area is rich in tufa barriers and formations, "tufa barriers are a rare global phenomenon" (Institut za vode J. J. Strossmayer, 2025) and therefore more valuable for preservation. The combination of dissolved limestone and blue-green algae, diatom algae, various bacteria as well as microscopic unicellular and multicellular organisms is responsible for a highly complex and sensitive process of tufa deposition (Javna ustanova Nacionalni park Plitvička jezera, 2019, pp. 38 -39).

A necessary prerequisite for this complex process of tufa formation is the very solubility of karst rocks, which are made primarily of calcium carbonate or limestone and are therefore highly dependent and sensitive to changes in hydrogen strength (pH) (Institut za vode, 2025).

The uncontrolled, massive influx of tourists represents one of the greatest threats to this process and to the "tufa barriers themselves, because they, despite the enormous structure that was built over millennia, are extremely chemically and mechanically sensitive. They are threatened by the increase in organic pollution (sewage, leachate from landfills, etc.), carbon dioxide, as well as disturbances in biological factors" (Institut za vode, 2025).

Our 2Parks are adorned with many incredibly beautiful tufa formations - please access this areas with the utmost caution, follow all rules and instructions!! Thank you!

SCIENTIFIC RESEARCH

It is important to recall that national parks have the primary responsibility to protect and conserve the nature and to promote scientific research and education. We wish to draw your attention to the importance of this demanding work of the institutions.

History of scientific research

Plitvice Lakes National Park 
Established in 1949, the area of the largest and oldest national park in the Republic of Croatia has a long history of scientific research - more than 160 years. The „heart“of the Park's research activities is located in the Scientific Expert Center "Dr. Ivo Pevalek". Research costs are a mandatory part of the annual financial plan.

Education is certainly one of the most important tasks of national parks!

The young of today are the future scientists, ecologists, and socially responsible entrepreneurs. The work with the young, especially from the surrounding local communities, is extremely important for the future of protected areas.

The first extensive study at the beginning of the 19th century was prompted by the impressive plant species richness and diversity of the Plitvice Lakes area.

Detailed research, conducted by academician Ph.D. Ivo Pevalek in 1924 and in 1936, were crucial to declare Plitvice Lakes a national park.

The study by Prof Pevalek have proved that fresh-water algae and moss play a very important role in the creation of tufa and the decisive influence that tufa and tufa-forming plants have on the structure and form, or morphology, of the lakes.

Among numerous studies, the one about the flora of higher plants carried out by scientists Šegelj and Krga in 1984, have proved Plitvice Lakes to be a unique phenomenon in terms of the richness and diversity of these plant species.
More here: Historical overview

Una National Park
As a relatively new institution, established in 2008, the Una National Park faces some unique and predictable challenges that are reflected in some of its fundamental tasks; nonetheless, scientific activities are slowly starting up. The research results as well as historical data collected from external sources, are included in a publicly available document Management Plan for the period 2026 – 2035 (Javno preduzeće Nacionalni park Una, 2026).

Ongoing Scientific Research

Plitvice Lakes National Park
In collaboration with the universities of Zagreb and Rijeka, Park is currently conducting four (4) scientific researches:

• Hydrodynamic modelling of the Plitvice Lakes system - project leader Prof. Zvjezdana Bencetić Klaić, DSc;
• Flora and the vegetation of mosses and vascular plants of the tufa barriers of Plitvice Lakes - project leader Prof. Antun Alegro, DSc;
• Sedimentology, stratigraphy and structural and geological traits of the Plitvice Lakes - project leader Prof. Borna Lužar Oberitera, DSc;
• Monitoring of morphological changes of the course of the Korana River - project leader, docent Igor Ružić, DSc.

More here: Scientific research

The Park regularly conducts three (3) important monitoring programs:

• Monitoring of indicators of water quality, eutrophication and the tufa-building process;
• Monitoring hydrological indicators;
• National water quality monitoring.

More here: Monitoring

Una National Park
The last major study began in 2012 in collaboration with renowned experts Prof. Đuro Huber, DSc and Prof. Josip Kusak, DSc from the Faculty of Veterinary Medicine University of Zagreb, Croatia, and lasted until the end of 2014. The research was primarily focused to describe the use of space, patterns of movement and activities of bears.

The Park is also currently participating in a few of projects.
More here: Una projects

NATURAL VALUES of 2PARKS

Geology & Hydrology

Plitvice Lakes National Park
The geological history of the Park is very long, with various rock formations. In 1979, it was among the first natural sites in the world to be registered on the UNESCO World Heritage List by virtue of its karst hydrography phenomenon. Plitvice Lakes belong to the Dinaric mountain system and share its geomorphological position with Una.

Dolomite rock formations found in the area of Upper Lakes are from the Triassic geologic period - between 245 and 202 million years old (JUNP Plitvička jezera, 2019, p. 34)!!

Active tufa barriers you stroll by have been in a continuous and complex process of creation between 6,000 and 7,000 years (JUNP Plitvička jezera, 2019. p. 36).

But these are not the oldest deposits discovered at the Plitvice Lakes. The oldest ones date back to the last ice age!

Within the last ice age there were four main cold stages called glacials or glacial periods (from old to young: Günz, Mindel, Riss, and Wϋrm, named after rivers and the lake Wϋrm in the Alps in west-central Europe) and interglacials (shorter and warmer geological intervals that separated main glacials).

Scientific dating have determined that the ancient barriers at the Plitvice Lakes or palaeo-barriers range in age from 250,000 to 300,000 years old (Mindel-Riss interglacial interval) and 90,000 – 130,000 years old (Riss – Wϋrm interglacial interval) (JUNP Plitvička jezera, 2019, p.36).

Una National Park
Una is also proven to have a long geological history, it shares its geomorphological position with the neighbouring Park, and just like the Plitvice Lakes belongs to the Dinaric mountain system.

Although Una stll awaits detailed scientific study, current data from the "Management Plan" suggests remarkable age of Una deposits:

The relative age of tufa formations in the Park range in age from 3,000 (active) up to 250,000 - 300,000 years old (palaeo) (Bosna-S Sarajevo i Elektroprojekt Zagreb, 2011, p. 27).

Una, the greatest natural value of the Park, has valuable relief forms formed by tufa deposition – barriers, islets, caves, and other forms (JPNP Una, 2026, p. 23). 

It is important to know that Una's flow is weakened due to a small number of tributaries, which is why the river and its protection is the highest priority of the Park. Positive developments occurred in 2024, when a comprehensive river water quality monitoring was carried out at as many as 22 measuring stations (JPNP Una, 2026, p. 26).

River water quality depends strongly on a stable flow state and the ecological purity of the river basin - right where a negative human impact is extremely high. The biggest threats are the discharge of inefficiently treated wastewater directly into waterways, the use of numerous caves and pits for waste disposal, and intensive agriculture which causes groundwater contamination with pesticides.

Habitat Diversity

The value of 2Parks' natural heritage is impressive, for example, there are 40 different habitat types recorded in the Plitvice Lakes National Park (JUNPPlitvička jezera, 2019, p. 45).

Una National Park is also expected to have a great diversity of terrestrial and aquatic habitats.

It is already known that Una's diverse vegetation on tufa barriers is significantly different from other habitats in fresh waters - 42 species of plants (25 species of algae and 17 species of moss) were found, almost all of which participate in the creation of tufa formations (JPNP Una, 2026, p. 37).

Forests

Beautiful forests cover about one third of the Earth's land surface and are of extreme importance in many ways.

Forests provide a high percentage of freshwater globally, prevent soil erosion and have a major impact on stable global climatic and hydrologic conditions (UNEP, n.d.).

Today mostly endemic, but still present in our area and other southern parts of Europe, are the so-called Illyrian species, indigenous Dinaric species that managed to survive the last Ice Age.

Plitvice Lakes National Park
Forests cover about 75% of the Park, everything from bushes to virgin forests. Areas of exceptional natural value under special protection are (JUNP Plitvičja jezera, 2019, p.24):

1. "Čorkova uvala" Virgin Forest - it was declared a special forest vegetation reserve in 1965 and is developing without direct human influence - represents the most beautiful primeval forest of the Dinaric Alps.

2.  Although it no longer exists, it is important to mention the former monument of horticultural architecture - „Skupina Tisa“, the Taxus baccata group (Yew trees) in Sertic Poljana, which was protected as a monument since 1962. Unfortunately, it was completely destroyed in the Homeland War in the 1990’s - cut out and taken into the unknown by the aggressor (Javna ustanova Nacionalni park Plitvička jezera, 2007, p. 43).

The most common forest species in the Park is the common beech (Fagus sylvatica), and the second most common is the common fir (Abies alba). Illyrian beech forests cover almost 95% of the total forest area in the Park, and are represented by four communities. There is also a whole range of other forest communities present, such as: spruce forests, sessile oak, common hornbeam, black alder, black hornbeam, Scots pine and other forest communities (JUNP Plitvička jezera, 2019, pp. 46 and 292).

Una National Park
The characteristic feature of the Una NP is that it encompasses three climatic zones (continental, mountainous and Mediterranean), which is reflected in the diversity of forest communities. The most common forest species are common beech, deciduous oak and noble broadleaf trees (Querco Fagetea) (JPNP Una, 2026, p. 40).

Particularly worthy of mention is a  population of a relict species - Platanus orientalis, commonly called Oriental plane tree or oriental sycamore, highly appreciated due to its rapid growth, abundant shade, and beauty (JPNP Una, 2026, p. 41).

Underground

Plitvice Lakes National Park
A total of 114 speleological objects (82 pits and 32 caves) have been recorded in the area of the Park. This number also includes speleological objects located up to 500 m outside of the park boundaries (JUNP Plitvička jezera, 2019, p. 35):

• 91 are of smaller dimensions (up to 50 meters long)
• 23 are medium-sized speleological objects (50-500 m).

Due to their exceptional natural values, in 1964 three caves were additionally protected as geomorphological natural monuments (Plitvička jezera, 2019, p. 24), each characterized by valuable underground karst formations and fauna (JUNP Plitvička jezera, 2007, pp. 42 – 43):

1. Cave Golubinjača - known for it's numerous cave formations and cave-adapted isopods.
2. Cave Šupljara - apart from valuable cave formations, Šupljara abounds in subterranean fauna: subterranean beetles, cave crickets, butterflies and cave-adapted isopods.
3. Cave Crna pećina (Vila Jezerkina) - rich in cave formations of various colors and sizes and a large bat population as well as mammals and cave-adapted isopods.

Highly worth the visit is one more valuable natural site in the immediate vicinity of the Plitvice Lakes NP - Barac Caves in Rakovica, permanently protected as a significant landscape since 2016. 
More here: Barać Caves

Did you know that stalagmites hold climatic signatures of the very distant past, in some cases up to millions of years! Help us protect caves - follow the instructions!

Una National Park
So far only one cave is registered near Martin Brod that stands out as a geological and landscape feature of the Park (JPNP Una, 2026, pp. 22 - 23). Considering that 2Parks have the same geological features as parts of the Dinaric karst area,  we can assume that the upcoming research will confirm the existence of an impressive amount of speleological objects.

Flora

Plitvice Lakes National Park
In terms of the richness and diversity of its flora, the Park represents a unique phenomenon. Based on systematic research, a great diversity of flora has been determined - more than 1,400 vascular plant species and subspecies (JUNP Plitvička jezera, 2019, p. 44).

The area of the Plitvice Lakes National Park and the "northwestern part of Lička Plješivica and the area from Vrelo Korenicko to Bjelopolje are part of an Important Plant Area (IPA) due to the exceptional composition of rare, endangered and endemic taxa and vegetation of high botanical significance" (JUNP Plitvička jezera, 2019, p. 44).

Also worth noting is an extraordinary diversity of orchids in the Park, including lady's slipper (Cypripedium calceolus) - Europe's most beautiful orchid, which is also a rare and endangered species (JUNP Plitvička jezera, 2019, p. 45)

It is worth mentioning one more species - Ligularia sibirica. This threatened Eurasian species can still be found in only a few localities in Southeast Europe - one of them being the Plitvice Lakes (JUNP Plitvička jezera, 2019, p. 45).

Una National Park
This biologically rich area has preserved primeval vegetation and abundance of vulnerable and endemic species in the gorges and canyons of the River Una.

Namely, rare refugial habitats and relictpopulations, tertiary relict species that survived the last Glacial Maximum, roughly 20,000 years ago, have been found in this area, such as communities on steep limestone rocky faces and cliffs (Asplenietea rupestris) and others (JPNP Una, 2026, pp. 37 - 38).

The ecological conditions in the Park have enabled the development of more than 850 vascular plant species, out of a total of 4500 plant species present in Bosnia and Herzegovina (JPNP Una, 2026, p. 39).

Analyses have identified over 170 medicinal and aromatic plant species, some of which are sage (Salvia officinalis), chamomile (Matricaria chamomilla), St. John's wort (Hypericum perforatum), thyme (Thymus serpyllum), peppermint (Mentha piperita), marigold (Calendula officinalis) and numerous other species (JPNP Una, 2026, p. 40).

Endemics

Endemic, plant or animal, species are unique to a defined geographic location, with narrow and wider distribution ranges.

Plitvice Lakes National Park
The number of endemic species present, of both narrow and wider distribution, is high –  about 1.7% (24 endemic species and subspecies), and consists of valuable specimens such as Croatian clove (Dianthus giganteus D'Urv ssp.croaticus), Dalmatian scilla (Chouardia litardierei), hellebore (Helleborus multifidus) and others (JUNP Plitvička jezera, 2019, p. 44).

Una National Park 
Although a detailed inventory of the flora is yet to be carried out, previous research and more recent field research, conducted for the needs of the current Management Plan, indicate numerous endemic species of local and wider distribution, many of which are rare; therefore, more endangered.

Local stenoendemic species (JPNP Una, 2026, p. 41):

• Una bellflower (Campanula waldsteiniana ssp.Unaensis)
• Moehringia bavarica ssp. Malyi.

Endemics of wider distribution (Bosna-S Sarajevo i Elektroprojekt Zagreb, 2011, p. 35): Dinaric (11 species), Balkan (15 species), Balkan-Apennine (10 species), Dinaric-Apennine (1).

A significant number of endangered species have been identified in the area of the River Una, including globally endangered species of sedge: greater tussock sedge (Carex paniculata), great pond sedge (Carex riparia), grass like sedge (Carex panicea), meadowsweet (Filipendula ulmaria), common reed (Phragmites australis), St John's-wort (Hypericum tetrapterum), etc. (Bosna-S Sarajevo i Elektroprojekt Zagreb, 2011, p. 35). Coastal sedge is a diverse and valuable habitat for various animal species.

The combination of dense vegetation and abundant food makes sedge an important habitat for reptiles, birds, and mammals!

Fauna

The biodiversity of fauna in the Plitvice Lakes National Park is impressive, and the vertebrate fauna, with the exception of small ones, is well researched with more than 250 identified species (JUNP Plitvička jezera, 2019, p. 57).

Initial research into the state of macrozoobenthos communities, small aquatic invertebrates, was conducted in the Una National Park area for the purposes of developing a Management Plan, and historical data from previous faunal research indicate a great diversity of species (JPNP Una, 2026, str. 41).

Invertebrates

Plitvice Lakes National Park
Numerous invertebrates in the Park are still awaiting more detailed research, but among the numerous insects, which constitute a significant species in the terrestrial habitats of the Park, the most notable and well-researched are the caddisflies or tularids (Trichoptera), of which as many as 90 species have been registered so far. Among them is one endemic species that has its home location precisely in the Plitvice Lakes, the Lika spring tularid (Drusus croaticus) and one special endemic subspecies that was recorded for the first time also here in the Plitvice Lakes area - the Plitvice reticulated tularid (Ryacophila dorsalis plitvicensis) (JUNP Plitvička jezera, 2019, p. 63).

There are 90 species of diurnal butterflies and 350 species of nocturnal butterflies, and scientists presume that the number of total potential Lepidoptera fauna in the Park is significantly higher (JUNP Plitvička jezera, 2019, p. 62).

The Park is also home to three types of the critically endangered butterfly species of the Lycaenidae family, the Blues, all three species are listed in the IUCN Red List of Threatened Species, the European Red List, and the Red List of endangered plants and animals of Croatia (JUNP Plitvička jezera, 2019, p. 62):

• The Large blue (Phengaris arion);
• The Mountain Alcon blue (Phengaris alcon rebeli);
• The Alcon blue (Phengaris alcon alcon).

Una National Park
In the researches conducted by Matočkin i Pavletić in 1959, 1960 and 1963, a total of 68 species of invertebrates were registered; the largest group, 19 species, also belongs to the group caddisflies (Trichoptera) (JPNP Una, 2026, p. 41).

It is worth highlighting 11 species of terrestrial snails (Gastropoda) found in the Una Canyon that persisted throughout the last glacial maximum (JPNP Una, 2026, p. 41).

About 75 species of butterflies have been recorded in the Park, but so far none of the endemic or rare species of invertebrates (JPNP Una, 2026, p. 41 – 42).

There is one very interesting group of organisms that are utilized to screen the health of the natural ecosystem in the environment - bioindicators. 

Studies have proven daytime butterflies to be valuable environmental indicators. In addition to being extremely sensitive to subtle changes in the environment, butterflies also play a vital role in terrestrial ecosystems.

The major threat listed for butterflies today is widespread destruction of their main habitats - pastures and hay meadows. 

Vertebrates

The accelerated extinction rate of vertebrate species that the Earth is experiencing right now represents a serious threat to our very existence as human species and life as we know it on our planet!

The number of extinct vertebrate species in the last century is the highest ever, with 617 species becoming extinct since 1900 (Ceballos et al., 2015).

The study, Accelerated modern human-induced species losses: Entering the sixth mass extinction, led by a team of scientists from universities of Stanford, Princeton, and Berkeley, says that Earth is in the midst of its sixth mass extinction of plant and animal species (Ceballos et al., 2015). But now with a big difference, this is the first that includes human beings!!

Based on the analysis of the fossil vertebrate record, researchers found that the rate of extinction has been up to 100 times higher than in periods when Earth was not going through a mass extinction event (Ceballos et al., 2015).

“The most serious aspect of this ecological crisis is the loss of biodiversity. The evidence is overwhelming that recent extinction rates are unprecedented in human history. On a human timescale, this loss would actually be permanent. Avoiding a true sixth mass extinction will require rapid, significantly increased efforts to conserve already threatened species and alleviate pressures on their populations—particularly habitat loss, overexploitation of the Earth’s resources for economic gain, and climate change. However, the window of opportunity is rapidly closing” (Ceballos et al., 2015).

 Fishes

Plitvice Lakes National Park
Nine (9) species of fish are registered in the waters of the Park, among which four (4) species are indigenous: brown trout (Salmo trutta), Italian minnow (Phoxinus lumaireul) and "recent research determined two target species: Italian golden loach (Sabanejewia larvata) and spined loach (Cobitis bilineata). Fishing was allowed until the 1990s, which, along with stocking in the 1930s and 1960s, was the most responsible for the six non-native species recorded in the Park's waters (JUNP Plitvička jezera, 2019, p. 61). Fishing is strictly prohibited today!

Una National Park
The latest ichthyological research in the Una River basin, conducted at the end of 2023, determined the presence of seven (7) fish species: brown trout (Salmo trutta), grayling (Thymallus thymallus), European bullhead (Cottus gobio), chub (Squalius cephalus) and the Eurasian minnow (Phoxinus phoxinus), and two allochthonous species, rainbow trout (Oncorhynchus mykiss) and schneider (Alburnoides bipunctatus) (JPNP Una, 2026, pp. 35-36).

Of the autochthonous species, the largest share of the ichthyological population of the Una River is made up of salmonid species: brown trout (Salmo trutta) and grayling (Thymalsus thymallus), which are widespread in the Una River throughout the Park area as well as in the River Unac (JPNP Una, 2026, p. 36).

Una is also graced by two endemic species: the European Minnow (Phoxinus phoxinus) and Huchen or Danube salmon (Hucho hucho), otherwise endemic to the Black Sea basin, and endangered in BA (VU according to the IUCN categorization). Another rare species found here is the spirlin or the double-striped uklia (Alburnoides bipunctatus) (JPNP Una, 2026, pp. 42-43).

"Due to declining water quality and habitat quality, these species are increasingly endangered, not only at the local but also at the European level. In order to respond to these challenges, the Park plans to regularly, on an annual basis, stock the Una and Unac rivers with indigenous species of brown trout and grayling" (JPNP Una, 2026, p. 43).

Amphibians, reptiles, insectivores, rodents and bats

Plitvice Lakes National Park
The world of small vertebrates is very diverse in the Park, but still insufficiently researched, with the exception of bats, which, like some other small species, are endangered and strictly protected.

Research to date has determined the presence of more than 50 species of mammals, of which 11 are target species. The list of target and strictly protected mammals includes 28 species (JUNP Plitvička jezera, 2019, pp. 57 and 295).

As many as 22 species of bats have been confirmed and mapped in the Park, and among the targeted and strictly protected species are seven species: the Mediterranean horseshoe bat (Rhinolophus euryale), the greater horseshoe bat (Rhinolophus ferrumequinum), the western barbastelle bat (Barbastella barbastellus), the common bent-wing bat (Miniopterus schreibersii), the long-fingered bat (Myotis capaccinii), Bechstein's bat (Myotis bechsteinii), and the greater mouse-eared bat (Myotis myotis) (JUNP Plitvička jezera, 2019, pp. 58 and 295).

Bats are an extremely important part of the ecosystem and one of the species known as bioindicators of environmental health!

They represent a very important link in the natural regeneration of forests because they disperse seeds and pollinate a whole range of plants that bloom at night, and they are also known as „natural pesticide". Feeding almost exclusively on a wide variety of insects and spiders, bats provide biological control of these populations!

Visit the Bat Night - the event takes place the last full weekend of August. Every year since 1997 in more than 30 countries, including the Plitvice Lakes and Barac Caves in our corner of the world, people have a chance to learn more about this valuable species.

Scientific research has also confirmed and mapped (JUNP Plitvička jezera, 2019, pp. 60 - 61):

• 13 species of reptiles (class Reptilia): of which as many as 10 have the status of a strictly protected species that must be provided with additional protection through the provision of special protected localities/reserves within the Park;
• 14 species of amphibians (clas Amphibia): and among them is the Italian crested newt (Triturus carnifex), a strictly protected and rare native species.

Amphibians are excellent bioindicators of environmental health due to their high sensitivity to chemicals. They absorb nutrients through their skin, as well as environmental toxins, which accumulate in their bodies faster than other species, and thus quickly reflect the state of environmental health!

Una National Park
The Park lists 65 representatives of mammals from 19 different families that are likely to inhabit the Park area. Which species are potentially target species of the Park and what is the general state of their abundance and vulnerability needs to be determined (JPNP Una, 2026, p. 43).

Among the species that are highly likely to have a habitat in the Park area are (JPNP Una, 2026, pp. 43 - 46):

• bats (Chiroptera) - it is presume that there are 20 species of bats from two families;
• reptiles (Reptilia) - the Park lists 16 representatives of reptiles from six different families, the most numerous of which are wall lizards (Lacertidae);
• amphibians (Amphibia) - the presence of 13 species is assumed, of which 3 are very rare, namely the alpine salamander (Salamandra atra), a relict species in BA (VU status), the alpine newt (Triturus alpestris) which is also an endemic species, and another very rare species in BA - the Italian crested newt (Triturus carnifex).

According to the IUCN criteria, the following species have the status of endangered (JPNP Una, 2026, p. 46):

• Olm or proteus (Proteus anguinus) - status vulnerable – VU;
• European tree frog (Hyla arborea) - status near threatened – NT;
• the alpine salamander (Salamandra atra) - status VU "at risk", otherwise it is a relict species in BA.

Amphibians make up one of the most diverse groups of terrestrial vertebrates, many of which are facing the threat of extinction!!

Some of the biggest threats to amphibians remain the loss of habitat, environmental pollution, pesticides and infectious diseases!

 Birds

This extremely important species plays a key role in keeping ecological systems in balance. Birds eat insects that can cause great damage to forests and agricultural crops. Birds pollinate plants, disperse seeds, and are also important scavengers in many ecosystems by removing the carcasses of dead animals.

Plitvice Lakes National Park
The ornithofauna of the Plitvice Lakes area is very rich, especially in forest habitats, characterized by numerous species. So far, 168 species of birds have been recorded in the Park, of which as many as 21 are target species (JUNP Plitvička jezera, 2019, p. 58)

The ornithofauna of the Park also boasts several valuable bioindicators of environmental health. The presence of the white-throated dipper (Cinclus cinclu) indicates the purity of aquatic habitats, and large and stable populations of owls and woodpeckers indicate the health of forest ecosystems. The most numerous owl in the Park is the Ural owl (Strix uralensis), which is also a target species, with an estimated 70-80 pairs in the Park, which is about 10% of the total population of this species in Croatia (JUNP Plitvička jezera,2019, p. 58).

What makes the Ural owl stand out is its population density in the Park, which is 5.4 pairs/10 km² in the beech-fir forests of the NW part of the Park. This is not only the highest recorded density of the Ural owls in Croatia, but also among the highest in Europe. A great indicator of the health of forest habitats (JUNP Plitvička jezera, 2019, p. 58).

Unfortunately, the threat to birds in the Republic of Croatia is very pronounced: out of 230 bird species that regularly nest in Croatia, as many as 91 species (39%) are on the Red List of Threatened Plants and Animals of Croatia, of which 56 species are endangered (categories of critically endangered (CR), endangered (EN) and vulnerable (VU) species) (Tutiš et al., 2013).

The use of natural resources, esp. water management, forestry and poaching, pose the greatest threat to Croatian birds - they threaten the survival of 89% of endangered species (Tutiš et al., 2013).

Una National Park

The Park's ornithofauna is still awaiting systematic research; however, based on existing data obtained through observations and studies of birds in the wider regional area, it is expected that more than 120 bird species inhabit this area (JPNP Una, 2026, p. 44).

Although there are no records of endemic species present, the Una’s ornithofauna is unique due to the presence of some rare and endangered species such as: western capercaillie (Tetrao urogallus), Corn Crake (Crex crex), hazel grouse (Tetrastes bonasia), woodpecker (the bird family Picidae), owl (order Strigiformes), tits (Paridae) and others (JPNP Una, 2026, pp. 44 - 45).

Among the protected bird species, the following stand out (JPNP Una, 2026, p. 45):

• Golden Eagle (Aquila chrysaetos);
• Peregrine Falcon (Falco peregrinus). 

Given the fact that the Park area is located on one of the main migration corridors of migratory birds on their way to Africa, the so-called Adriatic Flyway, which is part of the wider African-Eurasian Flyway, and considering existing scientific data concerning ornithofauna of the wider regional area, including Lika and Pokuplje area in Croatia, it is assumed that the number of species could be greater than 160 (JPNP Una, 2026, p. 45), but this will be determined by upcoming detailed scientific research.

Large mammals

Plitvice Lakes National Park
Certainly the most famous large mammal representative of our region is the brown bear (Ursus arctos), also a part of the Plitvice Lakes National Park logo design. Other large mammal species that live here are the gray wolf (Canis lupus) an the Eurasian lynx (Lynx lynx) (JUNP Plitvička jezera, 2019, p. 57).

All three species are included in the Red List of Wild Species of Croatia, are near threatened and protected by law in the Republic of Croatia (MZOZT, 2025).

This group of large mammals is also placed on the IUCN Red List of Threatened Species (IUCN, 2026), and all three present the Natura 2000 important species, EU rare, endangered or vulnerable species (MZOZT, 2025).

The presence of the Eurasian otter (Lutra lutra) has also been confirmed, which is a strictly protected species in the Park (JUNP Plitvice Lakes, 2019, p. 295). The Eurasian otter is also a legally protected species included in the Red List of Endangered Plants and Animals of Croatia (MZOZT, 2025), as well as a Natura 2000 important species (MZOZT, 2025).

Many other large mammal species have been registered here, including foxes, European wild cats, badgers, European pine martens, beech martens, European polecats, weasels, etc., and Park's large herbivores include European roe deer, red deer, and wild boars (JUNP Plitvice Lakes, 2007, p. 39).

Una National Park
The group of large mammals from the order of carnivores (Carnivora) is represented by the brown bear (Ursus arctos), the gray wolf (Canis lupus) and the Eurasian lynx (Lynx lynx), of which the brown bear and the lynx are at high risk of extinction in the wild in Bosnia and Herzegovina (JPNP Una, 2026, p. 43).

Among other carnivorous species, the presence of the golden jackal (Canis aureus) and the European wild cat (Felis silvestris) has been recorded, and after several decades of absence, two returning species have also been confirmed: the red deer (Cervus elaphus L) and the chamois (Rupicapra rupicapra), whose movements are monitored by Park staff (JPNP Una, 2026, p. 43).

The Eurasian beaver (Castor fiber), which is present along watercourses throughout the Park, is also under close supervision (JPNP Una, 2026, p. 43).

There is a high probability of finding other species of this order, but they need to be confirmed in future studies. The status of the Park's biodiversity as well as species status assessments are forthcoming, hopefully with the most positive results.

Thank you for taking the time to read! With joint efforts we can make a major contribution to the protection of nature!

Welcome to GWT2P Destination!

References 

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