Amsterdam Island cows were a rare breed of wild cattle (Bos taurus) introduced in 1871 and living isolated on Amsterdam Island.
Cows left behind more than 150 years ago in a remote part of the planet, the same distance from Africa, Australia and Antarctica, ended up thriving, giving rise to one of the few wild populations of domestic cows in the world.
Around 1871, a farmer from the French island of Réunion, located off Madagascar, took his family and their cows to the distant island of Amsterdam — which is approximately the same distance from Africa, Australia and Antarctica — in the hope of being able to survive there.
Less than a year later, the family returned to Réunion, leaving the cows behind. Although history has practically forgotten this failed expedition, science continues to study the cows that remained there.
Amsterdam Island is little more than a volcanic outcrop emerging from the southern Indian Ocean, so it is no surprise that the French colonists left so quickly.
What surprises scientists, however, is that the cows left behind ended up thrivinggiving rise to one of the few wild populations of domestic cows in the world.
At its peak, says the , the cow population on Amsterdam Island reached around 2,000 animals — with researchers who worked there seasonally still they slaughtered around 50 per year for food.
Despite their scientific value, especially for geneticists, these cows were an invasive speciesdestroying the ecosystem and becoming a threat to endemic plants.
To halt the effects of environmental destruction caused by cattle, the French government built an electrified barbed wire fence to confine the animals on the north side of the island, culling the herd south of that barrier.
With the success of these measures, it was decided to eradicate the remaining population in 2010. Still, these cows continue to help us understand how evolution and natural pressures shape life.
Why are they so interesting
There are few wild cow populations in the world, which means there have been few opportunities to study the “ferralization” process of cattle. One of the big surprises for researchers was the genetic diversity of cows on Amsterdam Island.
According to a published in 2024 in Molecular Biology and Evolutionscientists discovered that the island’s wild cows have greater genetic diversity than their domestic European counterparts, despite having originated in a founding group of just five individualsjust over a century ago.
Researchers speculate that part of the success of the Amsterdam Island cows is due to their pre-savage heritage.
The ancestors of abandoned cows were mostly Europeanvery close to the Jersey breed, originally from the United Kingdom. Its relatively small size and prior adaptation to cold and humid climates gave them an advantage in the island’s subpolar conditions.
Wild cows on Amsterdam Island have since been eradicatedbut they were not the last wild cow population in existence. In , wild cows, and their impact on the environment, as an analogue of , the wild and extinct ancestor of cattle.
In Alaska, the cows wild animals of Chirikof Island are being protected as genetic safeguard against possible disease outbreaks. For the cows on Amsterdam Island it is already late, but we can still protect the remaining wild populations.
