NAGANO –
A herd of an estimated 200 to 300 deer has been filmed within the Southern Alps, highlighting a quickly increasing inhabitants that specialists warn is damaging mountain ecosystems, stripping vegetation, growing landslide dangers and creating issues throughout Japan starting from crop losses to site visitors accidents.
The footage was taken on August 1 by an plane mechanic aboard a helicopter transporting meals and different provides to a mountain lodge. It confirmed an enormous herd overlaying the bottom close to Futagoyama, near Southern Alps National Park, which spans Nagano, Yamanashi and Shizuoka prefectures.
The deer had been noticed on the northwestern facet of the mountain in Nagano Prefecture.
“There were probably 200 to 300 of them,” mechanic Tatsumi Kawasaki of Toho Air Service stated. “At first I thought the grass was a different color, but when I looked closely, they were all deer.”
Shinobu Saito, supervisor of the Umanose Hut within the Southern Alps, stated she had by no means seen a herd of that dimension. “I had never seen so many deer together, so I was simply astonished,” she stated. “It made me realize that their numbers have increased far beyond what we had imagined.”
Wild deer typically reside for six to seven years, and one of many major components behind their speedy inhabitants development is their excessive reproductive capability.
Takayoshi Yamauchi, an affiliate professor at Iwate University, stated deer can proceed producing offspring quickly so long as ample meals is offered.
Large herds have been noticed within the space earlier than. Footage from three years in the past confirmed deer filling a part of a hillside earlier than all of a sudden scattering in all instructions.
Their growing numbers have turn into a significant issue within the Southern Alps, the place alpine vegetation is being closely broken.
Saito stated deer have eaten vegetation together with the Japanese globeflower, a flowering species discovered within the mountains.
Although deer are herbivores, their impression on vegetation may create dangers for individuals.
A big landslide that occurred in Maibara, Shiga Prefecture, in 2024 is believed to have been linked to feeding injury attributable to deer. Vegetation on the mountain was eaten away, leaving the floor uncovered and permitting water to move extra simply down the slope, contributing to the collapse.
Similar injury is being reported throughout Japan.
At Anji Kamo Shrine in Himeji, Hyogo Prefecture, deer have reportedly been coming into the grounds at night time for a couple of decade and consuming hydrangeas.
Chief priest Yoshiki Sanada stated as many as 10 deer can generally be seen directly and that they’ve turn into so accustomed to individuals and automobiles that they usually don’t transfer out of the best way when vehicles strategy.
In Koriyama, Fukushima Prefecture, deer brought about in depth injury to a area that was anticipated to supply about 1.8 million sunflowers for an annual pageant in August.
Chihiro Muramatsu, head of the organizing committee for the Konan Festival in Koriyama, stated the fields seen in each course had been presupposed to be crammed with sunflowers, however the vegetation had been nearly utterly destroyed.
Footprints believed to have been left by deer had been discovered all through the positioning in 2026, whereas safety digicam footage from a close-by area confirmed deer feeding on crops. The injury pressured organizers to cancel the pageant.
Deer are additionally creating rising dangers on roads.
In Sapporo, Hokkaido, collisions involving deer occurred in city areas in 2025. Across Hokkaido, the variety of site visitors accidents involving Ezo deer has been rising, reaching a report 6,705 instances in 2025.
In the Kanto area, one other member of the deer household, the Reeves’s muntjac, recognized in Japan as kyon, has additionally expanded quickly.
During reporting in Isumi, Chiba Prefecture, on August 31, a muntjac was noticed within the space, adopted by two extra crossing a street.
Footage from a digicam within the backyard of an area residence confirmed one of many animals noticing the digicam earlier than approaching whereas sniffing round.
According to Chiba Prefecture, Reeves’s muntjac populations had turn into established in solely 5 municipalities in 2004, however their vary had expanded to 18 cities and cities by 2025. The inhabitants is estimated at 94,100.
One Isumi resident stated the animals appeared to outnumber the town’s human inhabitants and that individuals had begun rising vegetation and crops that muntjac had been much less prone to eat.
Residents have additionally constructed selfmade fences, though the animals can leap over them from a standing place and transfer into neighboring properties. One resident stated newly sprouting greens had been notably susceptible.
The rising deer inhabitants is subsequently making a broad vary of issues, together with feeding injury, elevated pure catastrophe dangers and site visitors accidents.
Yamauchi stated the ecological penalties of deer might be extra extreme than these attributable to bears as a result of their numbers enable them to eat nearly all the undergrowth in forests.
“When there are large numbers of deer, they can eat all of the vegetation covering the forest floor, creating concerns about landslides and other disaster-prevention risks,” Yamauchi stated.
He stated heavy rainfall has turn into extra frequent and there have been repeated instances of muddy torrents resembling flash floods flowing down from mountain areas after intense rain, elevating suspicions that deer-related vegetation loss could also be contributing to the issue.
“The impact deer have on ecosystems is much greater than that of bears, so they are dangerous animals in that sense,” he stated.
Experts consider the worsening drawback can also be linked to the declining and ageing inhabitants of hunters in addition to local weather change.
Yamauchi stated the variety of hunters has fallen considerably and the remaining looking inhabitants is ageing, making it more and more troublesome to seize sufficient deer to manage their numbers.
Declining snowfall related to hotter temperatures can be permitting deer to develop into larger elevations the place they had been beforehand unusual, he stated, additional extending their vary into mountain ecosystems.
Source: FNN