Photo/Illutration Local authorities confirm the brown bear named OSO18 was culled on July 30. (Provided by the Kushiro General Promotion Bureau)

After years of evading capture, a brown bear that attacked 66 cattle in the eastern part of Hokkaido has been culled, according to Hokkaido government sources.

The bear, named OSO18, had been killing cattle around the towns of Shibecha and Akkeshi for the last four years, including an attack in June.

The damage to livestock exceeded 20 million yen ($137,000) in total.

Officials have confirmed that liver and tooth samples collected from the culled brown bear match OSO18’s DNA, finally putting the long hunt for the cattle-killer to an end.

Local authorities said on Aug. 22 that OSO18 was culled in Kushiro town on July 30. 

The first reported attack by OSO18 occurred on July 16, 2019, when a grazing cow was found dead in the Osotsubetsu area of Shibecha.

By September that year, 28 cattle had fallen victim to the bear.

Yet, the culprit behind this unprecedented aggression remained unclear.

After analyzing the footprints and hairs left at the sites, local authorities determined that the cattle had all been attacked by the same bear. It was named OSO18 after the 18-centimeter-wide footprints and the name of the area of the first attack.

The Shibecha town government began tracking investigations and patrols in cooperation with a local hunting association.

Still, the attacks continued. In 2020, five cattle were killed by OSO18.

The following year, the carnage spread to Akkeshi, which borders Shibecha. Three cattle were killed there that July.

As the threat continued to spread, an “OSO18 countermeasure meeting” was set up in November 2021 by the Kushiro General Promotion Bureau, which oversees the administration of a wide area.

Officials installed hair traps to collect bear fur for DNA analysis and tried capturing photos of OSO18 using an automatic camera.

In June, they successfully took the first color photograph of the notorious bear.

Previously, the animal was estimated to be a large bear weighing around 300 kilograms based on its 18 cm footprints. However, it turned out to be a typical adult male bear with a foot width of 15 to 16 cm and a standing height of around 2 to 2.2 meters.

Still, officials had little clue about OSO18’s whereabouts, admitting, “We don’t know where it is.”

The Kushiro bureau even considered using GPS to monitor cattle for abnormalities.

Masami Yamanaka, a senior member of the “Higuma no kai” (brown bear association) that has conducted the bear's research in the Shiretoko Peninsula for many years, pointed out OSO18’s high wariness.

“A bear cannot eat large prey in one sitting, so it usually stays near its prey. If we kill the bear there, that’s it, but (OSO18) disappears quickly,” Yamanaka said.

The fact that the bear avoided box traps and did not return to sites disrupted by humans suggested it was highly wary of humans, he said.

Yamanaka also pointed to the environmental conditions of the area. The affected areas were hilly with pastures intertwined with forests, making it difficult to determine the bear’s movements, he said.

Another factor was that eastern Hokkaido has a short snowfall period compared to other regions. The snow melts more quickly in the region, unlike areas with deeper snowfall. This meant that footprints remained visible for only a short period, which made tracking difficult.

Yamanaka also said that fewer hunters had experience pursuing bears during the remaining snow season, as bear hunting in the spring is prohibited.

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