A tiny parasite, believed to be living in a kind of hibernation in the bodies of millions of people around the world, can alter the behavior of wolves if noticed.
This is the result of a study published in the scientific journal Nature , but the researchers have been following wolves in Yellowstone National Park for 26 years and analyzed blood samples from the animals.
Controls the host
The parasite is a protozoan called Toxoplasma gondii and is mainly found in cats where it multiplies in the intestines.
New parasites are passed from the cat with faeces and can enter the body of any warm-blooded animal and live there – including humans, pigs, predators and rodents, which then become intermediate hosts for the parasite.
Various older studies have shown that the parasite changes the behavior of its intermediate host, and thus, for example, infected rodents become more risk-averse, less afraid, more aggressive, and not least the smell of cat feces attracts them.
The lack of fear is believed to be part of the parasite’s method of advancing into the cat’s intestine to reproduce. Now the new study shows that the parasite has the same effect on wolves, which, however, does not seem to be directly related.
Get to the top of the pecking order
The scientists observed 29 wolves in the national park and found that a quarter of them had antibodies against T. gondii in their blood and therefore had the parasite in them.
The infected wolves stood out very clearly: They were, for example, more risk-seekers and were 11 times more likely than others to leave the group and find a new territory.
It was also surprising that infected wolves were 46% more likely to become wolf pack leaders.
The reason for this is unknown, but the researchers cite the possibility that the parasite may stimulate testosterone production, which increases the wolves’ aggression and greed, helping them reach the top of the pecking order.
