[Animals] Why do some cats seem to get along with other cats? Their hormones offer a clue.

[Jeenyuhs]

Despite a reputation for preferring to share space on their own terms, cats often live in groups. This behavior may seem contradictory, but new research suggests it’s a curious consequence of domestication — and biological factors can help explain why some felines may embrace their fellow cats more than others.

 

 

In a study published Wednesday in the journal PLOS ONE, scientists link displays of cat behavior to hormones and the gut microbiome. These elements shape interactions among cats and may explain how they tolerate cohabitation despite their solitary nature. 

For example, the study found that cats with lower cortisol and testosterone levels were more tolerant of other cats and more willing to share food. Cats with higher levels of these hormones were less likely to interact with their fellow study participants. Meanwhile, cats with higher testosterone levels were also more likely to try to escape the room where they were observed. 

Researchers at Azabu University in Japan conducted the study. 

 

Although the study team hypothesized these results — cortisol and testosterone are known to influence aggressiveness — they did not expect to find that high oxytocin levels were not associated with a greater chance of being friendly or peaceful. 

“We were surprised at the results,” Hikari Koyasu, a postdoctoral fellow at Azabu University, said. “Even though a positive correlation between oxytocin and affiliative behavior has been reported in animals living in groups, results in [these] cats were the opposite. Cats with high oxytocin had less affiliative behavior with other cats.” 

 

In other animals, like wild chimpanzees and domesticated dogs, oxytocin surges bond groups together. However, while cats may spend time together in the same space, the study team proposed that “they might not be able to form tightly connected groups since each cat might consider the other cats out-group individuals.” 

Most wild cats live solitary lives, with the notable exception of lions. Researchers think that when the ancestors of pet cats self-domesticated, they concurrently developed the ability to live in groups without too much conflict — it was better to put up with other cats than lose the opportunity to be fed by humans. This change is reflected in hormone levels observed in this study and beyond; other researchers have found that cortisol concentrations are higher in European wildcats than in feral cats. 

 

This study’s oxytocin discovery shows that hormones do not necessarily act the same way across different species, said Maren Huck, a senior lecturer at the University of Derby. While an expert in cats, Huck was not a part of this new study and said she would like to see this result confirmed in further research on solitary animals. 

 

"NBC"