IUCN status
Scientific name
Proteus anguinus
Bosnia and Herzegovina, Croatia, Italy, Slovenia and France
Underwater caves

Cave salamander

Olms can live up to 10 years without food and are adapted to living in total darkness. They eat, sleep, and breed underwater. Feeding on crustaceans like shrimp, insects and snails. Olm are only found in underground cave systems in the Balkans and are Europe’s only cave-adapted vertebrate, but despite being thought to live more than 100 years, they reproduce just once or twice per decade.

Olms are an ancient species of salamander, and diverged from all other amphibians almost 110 million years ago. Research published in our Journal of Zoology uncovered that olms live a sedentary lifestyle, and they can often be found within a few square metres over several years. This means olms are especially vulnerable to the threat of water pollution, and there is little knowledge of their population size because of their inaccessible habitat. 

Olm swimming in the darkness of a cave through the rocks, pale pink snake like in appearance with four small lake. Smooth with no clear features.
Olm in the darkness of a cave, pale pink snake like in appearance with four small lake. Smooth with no clear features.
Global conservation updates
Stay up to date with the latest in wildlife conservation, as we work across the world to restore wildlife.

Protecting olms

Through our EDGE of existence programme, we supported Olm conservation to better understood these unique animals. Our partnership with conservationists based in Croatia built a better understanding of the species, helping inform work to protect their cave eco-systems. 

Amphibians and reptiles

  • Chinese giant salamander sitting on a rock beside a stream
    Creating a new future for an ancient species

    Chinese giant salamander conservation

    Together with our partners, we completed the largest ever wildlife survey in Chinese conservation history, and discovered just 24 giant salamanders, all of which were likely escapees from farms.

  • Mountain chicken frog sitting on forest floor

    Mountain chicken frog conservation

    Creating routes to recovery through cutting-edge scientific research and breeding at London Zoo.

  • Adder in the UK
    UK's only venomous snake


    The adder was once a common sight in large parts of the British countryside but in the last decade it has slipped into decline.

  • sand lizard examination in gloves
    A closer look at sand lizard translocations

    Analysing disease risks during sand lizard translocations

    The sand lizard has disappeared over much of its former range in the UK. Habitat loss and fragmentation are cited as the main factors in the species decline.

  • A group of conservationists tag a sea turtle on a beach
    Safeguarding sea turtles

    Sea Turtle Tagging

    Developing and applying innovative technology to protect species around the world. 

  • Reptile and amphibian conservation