KAMIKITAYAMA, Nara Pref. — It was a rainy Monday in July when Fumio Minamiura came across a shocking scene: a stray dog trotting along with the head and fore-parts of a young deer in its mouth. Blood was still dripping from the fresh kill.

A feral dog carries part of a deer along a road in Nara Prefecture.

Minamiura was driving up the Odaigahara Parkway to conduct research on wild deer and feral dogs. As a member of the Wildlife Conservation Committee in Nara Prefecture, a volunteer group set up 41 years ago, Minamiura is deeply interested in the problem of the overexpansion of the deer herd in the Kii Peninsula, which has resulted in disastrous damage to the forests in Odaigahara.

As forest browsers, deer nibble young shoots and saplings, and strip the bark from mature trees. If their numbers are not limited, they are capable of stripping mountainsides as cleanly as any timber company. According to Senji Iwamoto, a Nara prefectural government official at Odaigahara Visitor Center, wild deer have caused severe damage to trees on some 40 hectares of land in the 200-hectare eastern Odaigahara sector, including some 20 hectares which have been effectively deforested.

Historically, Japanese deer have been prey to wolves and man, but the Japanese wolf has been extinct since the last one was captured in Higashi Yoshino, Nara Prefecture, in 1905. Due to hunting’s decline in popularity in recent decades, the deer herd has grown to many thousands.

Another conservation organization, the Japan Wolf Association, has for some time advocated the re-introduction of wolves from foreign populations to bring the deer under control. But Minamiura’s discovery in June suggests that nature is already responding to the problem. As the photo shows, feral dogs may be replacing wolves as predators of the deer.

Minamiura had seen feral dogs several times at Mount Odaigahara, in the southeast of the prefecture, but this scene was the first clear proof of the role the animals could play in preserving the balance of the region’s ecosystem. The dog was brown, some 80 cm in length and about 17 kg in weight; from her teats, Minamiura could see the dog was a female raising a litter of pups.

“I am convinced that feral dogs can be an effective answer to the increasing number of wild deer,” says Minamiura. “These feral dogs are believed to live in packs of five to six. Most of them were abandoned by their owners and have adapted to living in the wild.

“In the Odaigahara area,” Minamiura says, “I think there are four or five such packs. Exactly how many live there and how they are living are questions I now have to work on.”

Iwamoto at the visitor center is doubtful that there are enough feral dogs to curb the wild deer population.

“Odaigahara is not a steep mountain,” he notes, “so the deer can usually run faster than the dogs. Unless the feral dogs outnumber the deer, they would not really be effective as a predator.”

Minamiura, however, thinks that the dogs would be a better option for controlling the deer than introducing foreign wolves to act as predators.

“There are plenty of wild deer for feral dogs to eat,” he says. “I hope to make further observations of the feral dogs, although they are very cautious and difficult even to spot.

“This photo was very rare, taken only by a lucky chance. I don’t think I will see a dog with a deer in its mouth like that again.”