EDGE Community

Project information

[Project name/title]
The Olm, Proteus anguinus in Croatia - Conservation research project plan

[Project description/overview]

This project focuses on the olm (Proteus anguinus), a cave dveling amphibian which is the only real cave vertebrate species in Europe. It is ranked 18th on EDGE list (and identified as a focal species) and 3rd on the Top 50 Evolutionarily Distinct Amphibians list.

In the area of the Dinaric karst, the olm is recognized as the most popular member of the subterranean fauna. Despite its popularity, general knowledge of the species’ ecology and biology is limited as it is a species that is actually rarely seen in nature and that is very vulnerable to human activity. Furthermore, there is a growing need for education of local communities in order to help the protection of this unique species.

The main reasons why the olm is endangered are the increasing and uncontrolled spread of urban areas and human made infrastructure, the uncontrolled excessive pollution of water habitats, and the use of crevices and cave entrances in olm habitats as landfill sites.

The olm is a species of European Community interest and a species in need of particularly strict protection, such as designating special areas of conservation and possibly reintroduction.


Croatia - Istra, Gorski kotar and Dalmatia

Project type:

Relevant EDGE species:
Olm (Proteus anguinus)

Project members:
Dušan Jelić

Relevant species
19. Olm (Proteus anguinus) VU

Europe‘s only cave-adapted vertebrate, the olm can survive for 10 years without food.

[Relevance description]

The aim of this project is to improve the baseline information available to conduct strategic conservation action planning for the olm in locations across its range in Croatia whilst raising general awareness among relevant stakeholders and local communities to facilitate achieving future conservation objectives.


- Improve the general knowledge of the olm distribution and ensure its long term survival

- Build up a scientific background for long-term conservation

- Create an action plan for removing or reducing the factors threatening the olm and its underground habitats

- Get local people involved in the conservation of underground habitats


In the area of the Dinaric karst, where it is a native species, spreading from north-eastern Italy, through southern Slovenia, Croatia and Bosnia and Herzegovina, the olm is recognized as the most popular member of the subterranean fauna. Students learn about it through their formal education and people are usually proud to have such a distinctive endemic species in their homeland. Despite its popularity, general knowledge of the species’ ecology and biology is limited as it is a species that is actually rarely seen in nature and that is very vulnerable to human activity. Furthermore, there is a growing need for education of local communities in order to help the protection of this unique species.

Project summary

The olm is has been recorded in 55 localities in Croatia but 12 of these have not been confirmed during the last 50 years. In order to update distribution data of the species, special effort will be given to confirm the data collected by speleologists and information sent by private contributors (questionnaires about sightings attached to educational material).

Population studies will be conducted on one of the three localities chosen based on the number of previous sightings, presumed population size and access to the site.

The localities are:

-           Rupećica spring and sink hole system

-           Miljacka II cave system

-           Temporary spring in village Vedrine near Sinj


The planned protocol of every captured/recaptured individual will be:

-           determination of sex

-           morphological data collection

-           DNA sampling

-           sampling for Chytrid fungus analysis

-           implanting Biomark PIT tags (8,5x2 mm)


Since detection of P. anguinus on the karst habitat is limited, we aim to collect fresh-water samples from different segments of the caves and analyse environmental DNA in order to assess the presence/absence of the species. Previous studies have shown that amphibian DNA was present in the water in sufficient quantity to detect a short monomorphic fragment of the species’ mitochondrial DNA even if amphibians were present in low numbers (Ficetola et al 2009).

In the beginning of the project we will print leaflets (2000 copies) with general data on distribution, biology, behaviour and conservation of Proteus anguinus in Croatia. The leaflets will also contain questionnaires for reporting the previous and recent sightings of olm in Croatia.

Public awareness is very important part of the project and we plan to have three workshops that will be held in three large areas where Proteus anguinus has been continuously recorded: Istria (city of Pula), Gorski kotar (city of Jezerane) and Dalmatia (city of Sinj). Education leaflets with olm sighting reporting forms will be distributed at these events and people will be asked to join the olm project Volunteer programme. Separate one-day training will be held for all the volunteers to give them sufficient knowledge to be able to help in further promotion of the project and setting up local educational teams and programmes.


a)    To assess the best localities for precise population studies within three chosen sites

b)    To collect genetic samples from different populations in the study localities

c)    To test for the presence of Batrachochytrium dendrobatidis (chytrid) within the sampled populations

d)    To conduct population and behavioural studies in the following areas:

- determine size and density of studied populations

- determine the demography of populations through long-term monitoring

- investigate the dietary habits and availability of prey

- determine potential predators

- investigate and describe main threats to these populations

- determine required protection actions for long-term preservation of these populations

- develop methodology for long term monitoring of Proteus anguinus

e)   Raise awareness among local people so that in the future they will be the initiators of olm conservation


With this project we expect to contribute to the current knowledge about one of the most mysterious species of amphibians in the world. Life characteristics of the olm are still unknown due to its unique and inaccessible underground habitat. All the results of this research will be published in Croatian and international scientific journals, and as a summary on the official web pages of Croatian Herpetological Society .

We hope to increase general knowledge on distribution, phylogeography, population dynamics and structure. This short-term study should set ground for much wider study of population ecology and ethology of olm in the future.

Raising of the awareness and educating the local people is the only way to protect highly sensible underground karstic habitats from pollution and destruction.

We also hope to create and test a new method for detection of elusive underground animals by using the environmental DNA technique. This could be a breakthrough in research of deep underground living animals that constitute the majority of endemic species in Dinaric karst area. These animals live in underground rivers and lakes that are impossible to reach in any currently known way, with their only connection to the world above ground is through the water that is pushed out. This water caries valuable samples that can prove the presence of the hidden world underneath.

Project members
Dušan Jelić : Project leader

I am a biologist from Croatia working on amphibian and reptile ecology and conservation.

[Member role description]
Within this project:
Management of project activities in Croatia.
Project partners

State Institute for Nature Protection - SINP, Zagreb (Državni Zavod za Zaštitu Prirode)

Trg Mažuranića 5, 10 000 Zagreb, Tel: +385 (0)1 5502 900,Fax: +385 (0)1 5502 901, Web: www.dzzp.hr, E-mail: info@dzzp.hr

SINP is an institution centrally responsible for specialized nature protection activities in Croatia. It was set up by the Decree of the Government of the Republic of Croatia dated 30 October 2002 and started operating in September 2003. The State Institute for Nature Protection performs a number of activities with the aim to ensure the maintenance and enhancement of nature conservation in Croatia in the long run by high quality expertise work.


Croatian Herpetological Society, Zagreb (Hrvatskog herpetološkog društva - HYLA)

Radučka 15, 10 000 Zagreb, Tel: +385 095 9050736, Web: www.hyla.hr, E-mail: hyla@hyla.hr

HYLA’s goal is to promote and develop research and protection of amphibians and reptiles and their habitats and to raise public awareness of the need to protect these species in Croatia. The Society and its members have years of experience in organising and carrying out public awareness campaigns about amhpibians or reptiles.


Hungarian Nature History Museum, Budapest (Magyar Természettudományi Múzeum – MTM)

Ludovika tér 2-6., 1083 Budapest, Tel: +36 1 210-1085, Web: www.nhmus.hu, E-mail: mtminfo@mttm.hu

The Hungarian Natural History Museum is one of the finest institutions of its kind in Europe, housing magnificent collections of major historical importance and an inspirational place. In order to promote understanding and protecting the natural world, the museum collects, researches, preserves, and presents objects and knowledge of science and the natural environment. The museum's mission is to make its precious collections, knowledge and expertise available for everybody via exhibitions, educational publications, special events and the museum experience. MTM has a newly built, well-equipped Molecular Taxonomy Laboratory, established in 2006, which is capable of fulfilling the project’s laboratory needs. The research scope of the laboratory covers molecular taxonomy and phylogenetics, phylogeography, population biology and conservation biology topics.


Autonomous Diving Club Society, Budapest (Autonóm Búvár Club – ABC)

Medve u. 15. II/26., 1027 Budapest, Tel: +36 20 4787070, Web: www.abc-e.hu, E-mail: abc-e@freemail.hu

ABC was formed by experienced divers in order to promote diving, and protection of underwater ecosystems. The club and its members own the required scuba diving equipment, and are willing to allow this to be used for the first phase of the proposed project. Members of ABC’s Cave Diving Group have extensive diving experience in low temperature underground underwater environment.

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Olm (Proteus anguinus) flushed out from cave system

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Associated Blog Posts
12th Sep 12
Since the Croatian Herpetological Society started the olm conservation project "PROTEUS” in 2011, we have hosted several very important meetings and round-...  Read

1st Mar 12
Hi! My name is Dušan Jelić and I live in Zagreb, the capital city of a beautiful country called Croatia (Central Europe). I have just become an EDGE Fellow...  Read

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