Cave guide Juan Pablo Maschio noticed the first olm egg and informed Postojna Cave management and scientists who work there. All other olms, which could disturb the egg-laying process or even eat the eggs, were removed from the aquarium, with only the dragon mum and her egg left in it.

The day of the big relocation has come. We carefully moved the rock into the special container, so that we could move it to the aquarium away from the main cave tour route. Some of the eggs fell off and we moved them onto the mesh-like metal construction – some sort of an olm 'nursery'. Their development now continues close to the surface, where there is plenty of oxygen.

On the 30th of May, 142 days after one of Postojna Cave's guides first spotted the olm egg, the first baby dragon was hatched. He was born into the darkness of the underground world and the light of the world of excited fans who have been waiting for him with baited breath since 30th of January 2016. 

Up and down, up and down, the hatchlings are romping around their containers. They love swimming to the surface and back to the bottom of the container. It seems they get more than enough energy from egg yolk. With their heads, which are already trapezoid-like in shape, they increasingly resemble adults. But they are not yet white, they are still nicely pigmented. On the largest of hatchlings, hind legs are already visible as well.

Yoyo has hatched! The last baby dragon. We named it Yoyo, as it was – while still inside the egg – literally hanging from the stone on a string, moving back and forth. A day before, the so-called Laggard had finally hatched too. This hatchling had wanted to really make sure it was worth coming out of the egg envelope. We noticed that in terms of their size and development the last two hatchlings were very similar to others who had hatched well before them. It looks like they were overdue, having developed in the egg envelope in the same way they would have outside of it.

The baby dragons are celebrating! It's been exactly one year since the first olm egg was found on the glass of the large exhibition aquarium. Our 21 baby dragons are now six centimetres in length. When they hatched, their front legs were fairly well developed with digit gaps, while their rear legs were underdeveloped with digit rudiments. Now, all of their four legs are developed with a total of ten digits. Their head, which was short at the time of hatching, now already resembles a duck's beak, their pigmentation is gradually disappearing, their eyes are still visible. When olms hatched, their mouths had no opening, but had teeth rudiments and yolk reserves. Now, the yolk is all gone, their predatory instinct is well developed and the baby dragons finish off their prey in no time without hesitating, which you see on the following link: https://www.youtube.com/watch?v=GP0xltqovrA

TIME TO MOVE

The baby dragons are leaving their ‘nest.’ With a calm hand and a bit of excitement, our biologist and the head of the cave laboratory moved the first baby olm from the Postojna Cave laboratory. His new home is a new exhibition aquarium at the entrance to the Tartarus (the part of Postojna Cave where the subterranean river Pivka flows and is closed for regular cave tours). He will soon be joined by two more baby olms and you'll have the opportunity to get to know all three of them.

After Postojna Cave was nicknamed the House of Dragons by a National Geographic journalist, it was time for the Protect Proteus Project – a sustainable project focused on raising funds to ensure optimal living conditions for our baby dragons (olms) and a long-term preservation of clean drinking water.

Olms are known to have some super powers. But anyone can be a superhero by purchasing a Protect Proteus lucky charm bracelet and supporting the project.

Viktor Got a Place of His Own

Viktor – the baby dragon who had his limb bitten off by one of his ‘cavemates’ during a wild scuffle, but then regrew it with the help of regeneration – got a place of his own. He has been moved to a new spacious aquarium, where he can have fun and relax all by himself.

It’s Been Ten Years Since the Very First Olm Egg

Back in late January 2016, we were astonished by the incredible news that one of the olms in Postojna Cave’s large aquarium had laid an egg. Touched by this unexpected piece of news, we made sure the egg had the perfect conditions and immediately got in touch with scientists. In the subsequent weeks and months, we excitedly kept a close watch on the olm eggs’ development, and for the first time ever, we made it possible for the curious public to watch them via infrared cameras. Our video and photo materials are an invaluable source of data for scientists, providing a penetrating insight into the olms’ lives. The baby dragons hatched in 2019 have made history as the world’s first fully documented olm litter.