Japanese Takagoyama Nature Zoo Culls 57 Snow Monkeys Carrying Invasive Alien Genes

Fifty-seven snow monkeys in Takagoyama Nature Zoo in the city of Futtsu, Chiba, northern Japan have been culled after zoo authorities found them to be carrying genes of an “invasive alien species.” The monkeys were killed by injecting them with a lethal injection.

According to zoo authorities, one third of the snow monkeys at the zoo had escaped from their enclosures and then crossbred with the wild rhesus macaque outside the facility. Rhesus macaques are native to China and India, are banned in Japan, and categorized as an “invasive alien species” in the country.

Zoo officials revealed that DNA testing confirmed that monkeys had been crossbred with the rhesus macaque.

Prior to killing, there were about 164 snow monkeys (Nihonzaru or Japanese macaques) at Takagoyama Zoo, and all were believed to be purebred.  Snow monkeys are a popular tourist attraction in Japan and can be seen bathing in hot springs in the wild. They have red faces, brown-grey fur, and short tails. They mostly live in colder areas that are covered with snow for most part of the year.

A zoo official told the Japan Times that the snow monkeys that crossbred with rhesus macaque had “to be killed to protect the indigenous environment.” If they escaped, they could reproduce in the wild and pose danger to native species.

According to Junkichi Mima, spokesman for conservation group WWF Japan, invasive species cause problems “because they get mixed in with indigenous animals and threaten the natural environment and ecosystem.”

“Preventing exposures to foreign animals is very important,” said Tomoko Shimura of the Nature Conservation Society of Japan.

According to zoo officials, a memorial service was held at a Buddhist temple to “appease their souls.”

Many people in Japan have reacted angrily to the culling.

“This seems a bit of a harsh response,” a user on Facebook said.

“Why? Send them out of Japan if need be, but killing them?” another added.

A ministry official from the Office for Alien Species Management said the culling was “unavoidable.”

“Keeping a government-designated invasive alien species is unlawful, if one cannot look after them in an absolutely secure facility in which an animal can never escape from,” the official said.

The zoo authorities have now tightened the security of the enclosure.