FUTTSU, Chiba Prefecture--About 100 native macaques are on the loose after a typhoon destroyed their enclosure at Takagoyama Shizen Dobutsuen (nature zoo) here.

The city-run zoo dedicated to native Japanese macaques was severely damaged by Typhoon No. 15 on Sept. 9, and about 100 animals escaped.

There are now fears that the Japanese macaques could start interbreeding with non-indigenous Rhesus macaques that originated on the Asian continent.

Residents are also incensed that they were not informed the monkeys had gone missing from the zoo until about a month after the fact.

A Futtsu city government official explained that local authorities had their hands full dealing with the damage from the typhoon. They also have no idea when new steel fences can be installed at the zoo because the city government lacks funds.

A visit to the zoo site on Nov. 9 confirmed that macaques are running around on top of toppled metal roofs and moving into and out of the facility through breaches in the metal fences. Feces was found on the ground in and around the zoo.

Takagoyama has been designated by the central government as a natural monument, with about 11 square kilometers set aside as a natural environment for the Japanese macaques. Emperor Emeritus Akihito visited the site when he was still crown prince.

The zoo is a major tourist draw in Futtsu, receiving about 10,000 visitors annually. The local tourism association has been managing the zoo for about 60 years.

When Typhoon No. 15 hit, the strong winds tore down the fences, freeing the 100 or so macaques kept there. Twenty are still unaccounted for. The remaining macaques return to the zoo during feeding times in the morning and evening, but essentially they are not being cared for.

Zoo officials contacted the public health office and local police about two weeks after the monkeys ran wild. The public was told two weeks after that.

While there have been no reports of injuries to humans, one woman in her 60s living near the zoo said, "I am worried about possible damage to farm produce."

The zoo has faced problems resulting from interbreeding in the past.

Efforts have been made by the Chiba prefectural government since 2005 to rid the Boso Peninsula area of Rhesus macaques.

Still, DNA testing in fiscal 2016 identified 57 macaques with genes of both species at the zoo. Those animals were euthanized to prevent further genetic contamination.

Naofumi Nakagawa, president of the Primate Society of Japan and a professor of primatology at Kyoto University, called for immediate steps to be taken as autumn is considered the breeding period for Japanese macaques.

"If the situation is one in which Rhesus macaques can easily enter the fenced area, work will have to start all over again to eliminate cross breeds," Nakagawa said. "The fence must be repaired without delay."

(This article was written by Susumu Imaizumi and Erika Matsumoto.)