There are brutal men in the animal kingdom too.Image: www.imago-images.de / imagebroker
On a small island in Lake Prespa, female turtles die from massive mating pressure. Researchers speak of a “demographic suicide” – and predict extinction by 2083.
Feb 19, 2026, 7:31 p.mFeb 19, 2026, 7:31 p.m
Kathrin Martens / watson.de
In the middle of the border triangle of North Macedonia, Albania and Greece lies a tiny island with a dramatic name: Golem Grad, translated as “Big City”. In fact, it is just 18 hectares small. The island in Lake Prespa is uninhabited, forested, surrounded by steep cliffs and notorious for its many water snakes.
Golem grade.Image: www.imago-images.de
But the real tragedy doesn’t take place in the water, but on land. Around 1,000 specimens of the Greek tortoise live on the so-called Snake Island – and their population is heading towards a bleak end.
There are 19 males for every female
The species is actually considered long-lived. But on Golem Grad the sex ratio is completely out of balance: there are 19 males for every female. What initially sounds like a statistical curiosity has fatal consequences.
Ecologist Dragan Arsovski from the Macedonian Ecological Society has been observing the animals since 2008, the “Standard” knows. Initially the population appeared dense and stable. But what his team documented in the years that followed is shocking.
Groups of males willing to mate literally pursue individual females. When they are exhausted, the group pounces on them. The males bite – sometimes to the point of drawing blood – and mount and push the fleeing females with the pointed ends of their tails. According to the journal Ecology Letters According to a published study, around three quarters of females have injuries to the genital area.
Female turtles throw themselves off cliffs
The long-term stress leaves its mark: the females are emaciated, reproduce less often, lay smaller eggs and have significantly lower survival rates than their counterparts on the mainland.
Particularly disturbing: Researchers observed several times how females threw themselves from the steep rocks into the void – even though the animals are actually good at climbing. An experiment brought clarity. Arsovski simulated a cliff in an outdoor enclosure.
Females from the mainland avoided the abyss. Many island females, however, threw themselves down – especially when there were several aggressive males in the enclosure. Some were pushed. But only the island females jumped voluntarily.
Forecast: extinction by 2083
Arsovski collected data for more than 16 years. The result is bitter because if nothing changes, the last female on Golem Grad will die in 2083.
The researchers speak loudly standard of a “demographic suicide”. No loss of habitat, no predators, no direct human intervention – the population collapses solely due to the extreme gender imbalance. Such a case has never been documented in the wild before.
It is unclear why there are so many males on the island. Females actually predominate on the mainland. A chance development – or human intervention – would be possible. Particularly puzzling: numbers are scratched into the shells of the oldest males. Nobody knows where they come from or what they mean.
Even Arsovski is in the dark. Despite discussions with numerous people from the region, there is no explanation. And while the mystery remains unsolved, the turtles are running out of time.