Courtesy of Shinshu University
Japanese sika deer have damaged alpine plants and other vegetation in the Southern Alps.
The Yomiuri Shimbun
12:14 JST, August 18, 2025
INA, Nagano — A wide-ranging initiative to reduce the number of Japanese sika deer around Mt. Senjogatake on the border of Nagano and Yamanashi prefectures has been launched in a bid to protect and regenerate vegetation in the area.
Starting this fiscal year, the Ina municipal government, the Environment Ministry and a council formed by the city and other entities to combat damage caused by pests in the Southern Japanese Alps has embarked on a project to protect alpine plants and virgin forest in the mountains from deer.
This initiative will cover areas near forest roads that the deer use and a remote mountainous area that previous attempts to rein in deer numbers failed to address. The project will also involve conventional methods such as deer fences.
Mt. Senjogatake, which stands at 3,033 meters, was once carpeted with alpine plants such as globeflowers to such an extent that it was affectionately known as the “flowering Senjo.” However, grazing by deer wiped out the flower fields and completely changed the mountain’s appearance.
Alarmed by this situation, the nearby Ina city government spearheaded the formation of a council with the prefectural government, the Forestry Agency, Shinshu University and other entities in fiscal 2007. The council has engaged in efforts to protect the vegetation such as by annually erecting deer fences to keep the animals out of an area that has gradually been expanded since fiscal 2008.
In the last fiscal year, the council installed a total of about 1,990 meters of netting, including some commissioned by the ministry, to surround 19 locations in the vicinity of Mt. Senjogatake.
In recent years, about 200 to 350 deer per year have been eradicated from Hase district at the foot of the mountain, generally between spring and summer, in a bid to reduce damage that the animals cause to crops. However, these efforts were mainly concentrated in areas near small villages and very few deer were captured deeper in the mountains. But now, the council has decided a more robust approach is required.
“Unless we bolster efforts to capture these animals in mountainous areas where it’s difficult to hunt them, we won’t fundamentally solve the problem,” an Ina government official said.
The council will attempt to trap the deer from autumn to early winter, when animals that had been at higher altitudes on the mountains come down and assemble in groups.
A deer population survey conducted by Shinshu University in autumn 2024 found that there were many deer at an altitude between about 1,900 meters and 2,200 meters near the Kitazawa-toge Pass, a base camp for climbers in the northern part of the Southern Alps. Mt. Senjogatake is also in this area. Consequently, the university concluded that reducing deer numbers near the pass was “essential.”
Based on this, the council commissioned a local hunting club to set about 60 snare traps near a forest road believed to be frequently used by deer to cross the pass. This intensive attempt to capture deer ran from May 18 until June 5 and captured 29 deer.
Since fiscal 2021, the ministry has also used snares to capture deer around the Umanose Hutte at an altitude of about 2,600 meters, near the Mt. Senjogatake summit.
“The alpine plants are starting to recover, but there’s still a very long way to go,” said Ina Mayor Takashi Shirotori, who also chairs the council. “This is a trailblazing project in Japan, so I hope it produces excellent results.”
AloJapan.com