Olm Diary

In 2016 the whole world was excited to witness a remarkable event. This is the story of the incredible development of our "baby dragons" from eggs to 8-month-old juveniles.

30.01.2016

DAY 01


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.

Did you know?

The pregnant female olm is fiercely defending her eggs from the other olms.

08.03.2016

DAY 39


Discovery Channel visited Postojna Cave to produce a feature about this one-of-a-kind event taking place in Postojna Cave.
The precious eggs have received extensive coverage by a number of media outlets across the globe. But no other camera is allowed near the eggs, except the infrared cameras recording their development in complete darkness. 

10.04.2016

DAY 72


The olms were seen making S-shaped movements, which made for a proper little dance performance and a source of entertainment for the cave visitors who were watching it on the screen inside the cave.

27.04.2016

DAY 89


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.

DID YOU KNOW?

Olms have a life expectancy of up to 100 years and can survive without food for up to 10 years.

30.05.2016

DAY 124


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. 

22.06.2016

DAY 146


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.

14.07.2016

DAY 168


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.

20.07.2016

DAY 174


The baby dragons are hungry. Five days ago, we treated the four oldest and largest ones to a proper feast – some delicious worms. Two of the hatchlings were happy to eat them. Although almost all olm hatchlings still have some yolk reserves left, the fact that they are already eating means they are developing just the way they are supposed to. In the days after, we fed the worms to the other hatchlings as well and we are happy to report that some of them munched their way through the prey like fearsome dragons. 

10.10.2016

DAY 256


This is the sound of our baby dragons carefully and slowly moving towards prey. Their hunting instinct is very much alive and kicking. Their eyes are clearly visible, the pigment is still present, but the yolk is all gone, as they now make sure they are not hungry themselves. The biggest baby dragons are between 4.5 and 5 cm long. As far as their looks are concerned, they are now already very much alike adult olms. 

30.01.2017

DAY 367


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

12.09.2019

DAY 1322


Victor is proudly showing off his new leg! A mere year and a half after a violent tussle between two young olms, the wounded ‘baby dragon’, Victor, has grown a new leg. We have kept a close eye on the olm’s remarkable ability to regrow limbs and have documented it all on a regular basis. The development of a new leg from a set of cells to a fully functional two-digit leg can be seen here.

04.03.2020

DAY 1496


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.

11.06.2020

DAY 1595


MEET THE ‘BABY DRAGONS’

We are proudly presenting our ‘baby dragons’. From today, Postojna Cave visitors can meet our baby dragons face to face. The only baby olms in history that we have been following since they were still eggs are now finally on view. You can visit them in the company of our biologists and learn all about these animals that can regrow the injured parts of their body, go without food for at least eight years, and live to be 100. You may even find out the secret of their eternal youth.