For years, scientists have sprayed the lions’ noses with oxytocin, called the love hormone. Result: they became much kinder to their neighbors and less quick to roar at lions they did not know.
This work, published Wednesday in the journal iScience, could provide valuable help in light of the urban expansion that is forcing some animals to congregate in reserves.
“I’ve always loved lions,” Jessica Burkhart, neuroscientist and lead author of the study, told AFP. After studying the brains of these animals in the laboratory, she wanted to observe them in real life.
While cats have a reputation for being independent, lions reject that trend. They live in groups and win and defend territories on the African savannah.
“For example, male lions leave their group when they are a few years old, meet other males they do not know (…) that they will commit to for life,” he said.
This type of behavior indicates that lions – unlike leopard or cheetah lizards – are biologically attached to being social in certain situations. Which made it an interesting animal to test for oxytocin.
– Greater tolerance –
Oxytocin strengthens social bonds. It appears in a mother’s brain looking into her newborn baby’s eyes, causing a feeling of happiness and well-being. Some therapists even suggest that couples facing marital problems look into each other’s eyes to release oxytocin.
Similar effects have been observed in other species, for example between humans and their dogs.
Jessica Burkhart and her colleagues worked in the Dinokeng Game Reserve in South Africa and used pieces of meat to lure lions.
The hormone had to be injected directly onto their noses using something resembling an old perfume bottle to reach the brain directly.
The 23 lions that received the treatment proved to be more tolerant of other lions in their space, especially when they were in possession of a desirable object.
“When the lions received oxytocin, they got their favorite toy, and we saw the distance (between them and their relatives) reduced from 7 meters without treatment to 3.5 meters with it,” Jessica Burkhart detailed.
Treated lions also no longer roared back to listen to recordings of intrusive roars – unlike lions that received no treatment or others that had only been sprayed with saline solution.
– A fear –
This reduced aggression towards alien lions is particularly encouraging, according to the researcher, because oxytocin is also known to have a perverse effect in humans: if it evokes positive feelings towards close humans, it can also increase rivalry to outsiders.
According to Jessica Burkhart, this treatment can be helpful in several scenarios.
First, it could help lions rescued from circuses or zoos in war zones and then placed in shrines.
In addition, lions are facing a growing problem: Cities are expanding and penetrating more and more into their territory. Defenders of animals must therefore transport them to reserves where groups who do not know each other are forced to rub themselves. Oxytocin could help prevent conflicts here.
Finally, the treatment could also help when the lions return to the wild, adapting better to their new social environment, making them “more curious and less scared,” according to Ms. Burkhart.
But the treatment also raises fears that unscrupulous people – in the style of zoo officials portrayed in the documentary series “In the Kingdom of the Wild” – will use it to allow visitors to pet animals. A practice that is much criticized by associations.
“There are indeed corrupt people. But we can hope that oxytocin will help more than it will cause harm,” the researcher wants.