It used to be that animals need much more time to lose the instinct of self-preservation.
Researchers from Melbourne University found that in 13 generations the northern marsupial martens, growing up far from predators, cease to be afraid of them. They wanted to save the animal population, but when they were returned to their usual habitat, it turned out that they had forgotten how to survive.
Scientists constantly resort to moving species to a safe zone without predators, if the animals are threatened with extinction. However, this can lead to a complete loss of the instincts necessary for survival in the wild. It was believed that this process is rather slow, but the northern marsupial marten changed the views of scientists.
In 2003, the martens were threatened with extinction: although they themselves were predators, they were successfully hunted by dingoes – secondarily feral home dogs. To save the population several individuals were transported to a separate island north of Australia. There were no predators eating martens, and the researchers expected to return the animals to the mainland, as soon as their numbers grow sufficiently.
To test their hypothesis, the researchers took several individuals from three groups of martens: grown on the mainland, grown up on the island and raised in captivity. They put food in front of them, but to get to it, it was necessary to thrust the muzzle into the hole with dingo or cat hair. The scientists considered the time spent near the feed and the amount eaten.
It turned out that the mainland martens spent more time investigating boxes of food and less eaten, just as their descendants grew up in captivity.
But the island martens behaved differently: they did not react to dingo wool and were bolder. It is believed that martens managed to survive among predators due to the fact that they avoided the places of their appearance, but after 13 generations they lost this instinct.
One researcher suggested that the reason for this may be survival features on the island: there was a small amount of food, so the brave martens had more chances, and this contradicts the principle of survival among predators.