Leos are generally not inclined to make new friends. Giant cats fiercely defend their territory and can mortally injure an enemy with a single swipe. While aggression is an advantage for apex predators in the wild, it poses real challenges for lions in reserves or captivity, a number that is increasing due to habitat loss. Researchers working at a wildlife sanctuary in Dinokeng, South Africa, found that an intranasal application of the “love hormone” oxytocin could make lion meat-cuts less lethal. Their work appears March 30 in the journal iScience,
In the summers of 2018 and 2019, a team led by University of Minnesota animal biologist Craig Packer and neuroscientist Sarah Heilbroner spent their days using a pile of raw meat to lure lions to a fence so they spray oxytocin on their noses. can do Appliance that looks like an antique perfume bottle.
“By spraying oxytocin directly on the nose, we know it can transport the trigeminal nerve and the olfactory nerve directly to the brain.” First author Jessica Burkhart says. “Otherwise the blood-brain barrier can filter it out.”
After these treatments, Burkhart and his colleagues observed that 23 lions who were given oxytocin were more tolerant of other lions in their location and displayed less alertness to intruders. “You can see that their features soften immediately, they go from wrinkly and aggressive to this completely calm demeanor,” Burkhart says. “They completely calm down. It’s amazing.”
Researchers measure social tolerance by observing whether a lion that has a desired object, in this case a toy, will allow others to approach it. “When the lions were treated with oxytocin, and we gave them their favorite pumpkin toy to play with, we observed that the average distance between them dropped from about 7 meters to about 3.5 meters after the oxytocin was administered.”
In a scenario where food was present, however, the big cats did not show an increased tolerance to each other even after they were given hormones. Importantly for future introductions, hormone-treated lions significantly reduced their alertness to potential intruders, never roaring in response to the recorded roar of unfamiliar lions, whereas untreated lions always roared in response.
This type of treatment can be especially helpful as cities in Africa spread and encroach on lions’ territories. To keep them safe and away from humans, many have been moved to private fenced reserves, often resulting in lions from different herds mingling with each other. “We are currently working on the introduction of animals that have been rescued from circuses or overseas or war zones that now live in sanctuaries,” Burkhart says. “Hopefully this will translate to animals relocating to the wild, helping them become more accustomed to their new social environment so that they are more curious and less fearful, leading to more successful bonding.”
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