According to recent findings by a University of Montana student and his colleagues, wolves in Yellowstone National Park are more inclined to take risks and become pack leaders when they are infected with a common parasite linked to cats.
Major news outlets picked up the story. The study was first reported in the journal Communications Biology.
Connor Meyer, a wildlife biology doctorate student at the University of Michigan‘s Ungulate Ecology Lab, a unit of the W.A. Franke College of Forestry & Conservation, said of the research, “I’ve been blown away by it.” “I’m shocked and grateful, but it’s been a little unnerving with all the attention,” the speaker said.
Toxoplasma gondii, also known as the “mind-control parasite,” is a single-celled organism that Meyer and his team studied to produce the sensational story. It prefers to reside in felines, and infected cats excrete oocysts that are spore-packed. T. gondii, sometimes known as “toxo” by Meyer, is the reason pregnant women shouldn’t clean the litter box. Although the parasite is often controlled by human immune systems, it can be hazardous to fetuses and people with impaired immune systems, such as individuals with HIV/AIDS.
All warm-blooded mammals can contract T. gondii, and a third of people are thought to be carriers of the infection. The parasite settles in the muscles and the brain and is known to increase testosterone and dopamine levels. Behavior is impacted by this: According to studies, infected rodents become less afraid of cats or urine from cats and become more active outdoors, increasing their likelihood of being eaten. Chimpanzees kept in captivity who are infected stop being afraid of leopard urine.
It almost seems like the parasite is controlling them biologically to allow it to return to the cozy interior of its favorite feline host. But do animals that don’t normally go through the T. gondii life cycle also become affected?
In the spring of 2021, Meyer and Yellowstone Park scientist Kira Cassidy began a rigorous investigation of the incidence of T. gondii among park wolves. They found that wolves that are toxo-positive take greater risks and are 46 times more likely to become pack leaders and leave their original pack.
One of the most researched species in the world is the Yellowstone wolves. Park managers have obtained blood samples each time a wolf has been captured and collared since they were reintroduced in 1995. Through the help of a diagnostics lab at Cornell University, Meyer and his team ultimately tested the blood of 243 wolves for toxoplasma antibodies. They also made use of information from the current and extensive Yellowstone Wolf Project study. T. gondii infection was found in 74 of the wolves examined, accounting for more than 27% of the total.
The primary food of wolves, elk, was initially thought to be the source of the infection, the researchers surmised. However, none of the more than 100 elk that were tested for the parasite proved positive.
Finally, Meyer stated, “We discovered that the most important indicator of wolf infection was when their range overlapped regions with high mountain lion density.” Therefore, since no elk tested positive, we surmised that cougars were the source of their infection.
Only about 10 instances of mountain lions being killed and eaten by Yellowstone wolves have been reported since 1995. According to Meyer, wolves are more likely to become infected by toxoplasma by prowling around “scrape sites,” which are places where cougars establish their territory by urinating.
He added, “We also have a litter box theory.” Almost everyone with a dog and cat in the house is aware that the dog will loot the litter box if given the chance. Although there is no concrete proof that wolves have eaten mountain lion scat, there are several pictures showing wolves eating scratches from mountain lions. “We don’t believe it is too far of a leap because wolves consume a wide variety of foods.”
Meyer emphasized that they are not saying that toxoplasma makes wolves become leaders.
He added that other factors besides toxo also influence whether wolves will be pack leaders. “Like with people, it’s one of several factors that influence wolf behavior.” In our study, toxoplasma positivity reduced the time it took for individuals to disperse, but toxoplasma negativity did not affect dispersal or the ability of individuals to become pack leaders. “We’re not saying Toxo is in charge of everything; we’re just saying it might speed up some of these behaviors.”
He added that both of the two leaders of wolf packs, usually a male and a female, are equally likely to test positive for the parasite.
Meyer, a Whidbey Island native, originally developed an interest in the T. gondii life cycle while a student at the University of Washington. Dr. Matthew Metz, who received his Ph.D. from UM last year, was then hired to work for the Yellowstone Wolf Project, and he soon started working for the Yellowstone Cougar Project as well. He worked on numerous research projects over a six-year period, which put him in contact with Professor Mark Hebblewhite, head of the UM’s Ungulate Ecology Lab. Meyer began asking questions about graduate school.
“I had an interest in coming here since UM is one of the greatest graduate programs in wildlife biology in the country, if not the best,” Meyer said. According to Mark, working on the toxo article may help me get into his program.In 2021, when I first arrived at UM, Mark and I were working on a study on Canadian elk migration. “I felt a little more confident after finishing this paper as I dove right into a rigorous Ph.D. program.”
Meyer said we need to study more about the parasite despite his concern that some reports concerning T. gondii may be overly sensationalized and that too much may be given to its purported mind-bending abilities. According to studies, toxoplasma-infected people are more likely to appreciate cats, experience schizophrenia, or act out in the street. According to a recent study conducted on a college campus, toxo-positive students were typically considered to be more attractive.
Is it playing tricks on our minds?
Meyer declared that there must be more work to be done. Fortunately, we had all of that fantastic data from our study as well as all of the blood serum and the time, inclination, and encouragement to look into it.
