A study of 26 years of wolf behavioral data and analysis of the blood of 229 wolves revealed that the parasite infection Toxoplasma Wolves are 46 times more likely to become pack leaders.
The study says the impact of this parasite in the wild is horribly understudied and its role in ecosystems and animal behavior underestimated.
If you have a cat, you’ve probably heard of this parasite. This microorganism can only reproduce sexually in cats, but it can infect and reproduce in almost any warm-blooded animal.
This includes humans, who are usually asymptomatic (but Potentially deadly) is called a parasitic disease Toxoplasmosis.
Once transferred to another host, the individual Toxoplasma If the parasites don’t want to become an evolutionary dead end, they need to find a way to get their offspring back into the cat’s body — and they have a kind of creepy way of maximizing their chances of doing so.
Animals etc. mouse or rat Cats infected with the parasite become more risk-taking and in some cases become fatally attracted to the smell of cat urine, making them more likely to be killed by the cat.
For large animals, e.g. ChimpanzeeThis means a higher risk of encounters with big cats such as leopards. Infected hyena Toxoplasma Also, Killed by a lion.
Wolf(CanineThe bears in Yellowstone National Park are not technically prey for cats, but their habitat is dominated by pumas (PUmacon Color), known carrier Toxoplasmaand both species prey on moose (Canadian deer),bison(Bison Bison), Mule deer (Odocoileus hemionus) is also there.
Wolves can also occasionally become infected by eating dead mountain lions or ingesting mountain lion feces.
Data collected on wolves and their behavior over nearly 27 years has provided a unique opportunity to study the effects of parasites on animals in the wild. Intermediate host.
The researchers, led by Yellowstone Wolf Project biologists Connor Meyer and Kira Cassidy, also examined blood samples from wolves and mountain lions. Toxoplasma infection.
Wolves whose territories overlap with those of mountain lions were found to be more likely to become infected. Toxoplasma.
However, there were also behavioral consequences, such as a significant increase in risk-taking behavior.
Infected wolves were 11 times more likely to leave the pack and migrate to new territory, and infected males had a 50% chance of leaving the pack within six months, whereas uninfected males more commonly left the pack within 21 months.
Similarly, infected females had a 25% chance of leaving the group within 30 months, compared with 48 months for uninfected females.
Infected wolves were also significantly more likely to become pack leaders. Toxoplasma Testosterone levels increase, which can result in increased aggression and dominance, traits that help wolves establish themselves as pack leaders.
This has several important consequences: pack leaders breed, Toxoplasma Contagion can be congenital and passed from mother to offspring, but it can also affect the dynamics of an entire herd.
“Gray wolf packs have a communal structure that gives pack leaders a disproportionate influence over pack mates and group decisions.” The researchers write in their paper:.
“If the leader wolf gets infected Toxoplasma and exhibit changes in behavior…This can create a dynamic where behavior caused by the parasite in one wolf can affect other wolves in the pack.”
For example, the leader of the pack cougar urine smell As they boldly venture into new territory, They may be more exposed to parasites, resulting in Toxoplasma The infection spreads throughout the wolf population, creating a kind of feedback loop that leads to increased duplication and infection.
This is compelling evidence that small, understudied factors can have large effects on ecosystem dynamics.
“This study shows how community-level interactions can influence individual behavior and has potential extensions to group-level decision-making, population biology and community ecology,” the researchers said. write.
“Incorporating the effects of parasite infections into future wildlife studies is essential to understanding how parasites affect individuals, groups, populations and ecosystem processes.”
This study Communication Biology.
A previous version of this article was published in November 2022.
