Lonely, sexually frustrated dolphin may be attacking swimmers in Japan, researchers say
A spate of dolphin attacks on swimmers in Japan’s Fukui Prefecture is being blamed on one bottlenose dolphin, who researchers believe may be particularly lonely, having been separated from a pod.
According to NBC News, Japanese news service NHK reported last week that a man had been bitten on both hands by a dolphin while swimming at a beach in the city of Tsuruga. The man was the 18th person to be bitten by a dolphin in the area since July 21. Since 2022, more than 45 people have been injured in the area.
Based on unique fin markings captured on film and in video, it is believed that many of the incidents are linked to a single male bottlenose dolphin.
Watch: Viral video captures bottlenose dolphins rocketing high through the air
A lonely dolphin
Because bottlenose dolphins are generally highly social animals that live together in pods, and this dolphin has been spotted swimming alone, marine researchers say that the dolphin’s unusual behavior may be caused by loneliness and sexual frustration after being isolated from a pod.
Tadamichi Morisaka, a dolphin ecologist at Mie University in Tsu, Japan, told Nature.com that playful biting is a common behavior amongst male bottlenose dolphins, who almost always live in pairs and groups.
“This includes behaviors like chasing each other and rubbing the other dolphin with their pectoral fins – which is thought to signal fondness – and even sexual behaviors, such as pressing their penises against each other,” Morisaka said, adding that “Gentle biting is one of these pro-social behaviors. So the dolphin in Fukui is acting like he’s playing with a male pairmate, but with humans instead.”
James Cook University researcher Putu Mustika said that dolphins can also become aggressive when exhibiting mating behaviors and may misinterpret human interactions.
It remains unclear, though, why this dolphin, in particular, has become isolated from its companions.
In response to the increasing attacks on swimmers, officials have increased lifeguard patrols in the area and reduced swimming hours to try and reduce human interaction with the lonely marine mammal.
Another lonely dolphin in 2018 exhibited similar behavior
It’s not the first time a dolphin has found itself alone and run afoul of humans.
In 2018, the French village of Landevennec had to temporarily ban swimming after a lone bottlenose dolphin, nicknamed Zafar, became overly playful with humans in the water. The 10-foot long Zafar tried to block multiple swimmers from returning to land and repeatedly bumped against swimmers and kayakers while swimming next to them.
Much like the bottlenose dolphin spotted off the coast of Japan earlier this month, Zafar was described as “sexually frustrated.”
Max Hauptman is a Trending Reporter for Paste BN. He can be reached at MHauptman@gannett.com