This winter, naturalist and woodland conservationist C.W. Nicol will be busy cooking up delicious meals using wild deer meat — slow-cooked keema curry, hearty shepherd's pie and soy-simmered nikudango meatballs, to name a few.

Like Nicol — a prolific author and broadcaster whose "Old Nic's Notebook" appears on this page every month — if more people start to incorporate venison into their diets, Japan may come closer to solving the problem of deer overpopulation that is threatening forests nationwide.

According to Koichi Kaji, a professor at Tokyo University of Agriculture and Technology, deer numbers rise 20 percent annually, meaning the population in Japan — presently estimated to be up to 875,000 — could double every four years. Now, even though around 140,000 animals are culled annually, that's not enough to keep pace with their rapid reproduction.

The current state of affairs — with the vegetation in nine of Japan's 29 National Parks classed by the Mammalogical Society of Japan as "suffering serious damage from deer" (as well as that in many quasi-National Parks) — differs sharply from previous eras.

Since ages past, Hokkaido has been home to a thriving population of sika deer (Cervus nippon), the indigenous variety of the Cervidae deer family native to much of East Asia. However, following the Meiji Restoration in 1868, people from other parts of Japan were encouraged to move there to exploit the sparsely populated northern island's natural resources — among them its deer. Although the animals had long been hunted for food by indigenous Ainu people using bows and arrows, the immigrants soon wrought drastic changes.

The new arrivals cleared forest areas for agriculture and used guns to hunt deer in large numbers, harvesting more than 500,000 a year betweem 1873-78 alone. Canneries were built, and their exports became a major source of income. Consequently, by 1900 deer numbers were down to near-unsustainably low levels.

As a result, from 1879, the Hokkaido government initiated various bans on hunting that covered much of the island for many years up to 1950, by which time deer numbers had recovered.

Since then, several factors have led to their successful repopulation of Hokkaido and other parts of Japan, with their range expanding by 70 percent since 1990.

Among these has been the increased area of pastures to meet growing demands for beef and milk — pastures that also provide easy grazing for deer. Postwar global warming and reducing snowfall have also allowed more deer to survive the winters. Meanwhile wolves, long their prime predators, were exterminated from Hokkaido and Japan's other main islands around the turn of the 20th century because they preyed on domesticated animals as well.

With climatic changes in their favor, and wolves gone, deer numbers continue to explode. Moreover, with rampant rural depopulation, and with it a decline in culling, the situation has become so serious that many local authorities are now paying hunters to control numbers.

Deer are voracious. Left to themselves, after clearing the forest floor of non-poisonous plants, they begin to nibble away at tree bark, which often kills the trees. Rare species of vegetation, dwarf bamboo and slow-growing elm and oak are most vulnerable.

Moreover, overgrazing by deer, Kaji warns, carries consequences that go beyond the disruption of ecosystems. Damage to the forest floor leads ultimately to soil erosion and, in some cases, landslides, he notes.

"After eliminating the surface vegetation, there is bare ground and the soil washes away," he explains.

Although the problem is most severe in northern Japan, Kaji, who has been studying deer populations for more than 30 years, says it is not limited to Hokkaido.

"They climb nearly to the top of the mountains in Nagano Prefecture and damage the alpine grassland (and delicate flora). It's awful," he reports.

Those living in the nation's capital don't have to go far to witness the downside of these Cervidae ruminants. The deer have harmed vegetation in the Okutama area of western Tokyo, site of the Ogouchi Reservoir, which is the city's major water resource.

Due to such problems, many local governments now pay hunters to cull the animals. But due to the shrinking number of hunters and the high cost of disposing of carcasses, the deer are still dominating.

Nicol advocates creating a federal corps of forest rangers and veterinarians to manage wildlife populations.

"There should be game wardens or rangers trained to assess the deer damage and cull them; vets to examine the meat and say, 'This is OK for people to eat, or not,' " Nicol urges. "We are pushing the new government to establish real foresters."

But for now, he says efforts should focus on encouraging people to eat venison.

Earlier this month, Nicol and Kaji both spoke at a Tokyo symposium intended to shed light on the issue, and last year Nicol had a book published, titled "Shika Niku Shoku no Osusume" ("Recommendations on Eating Deer"), in which he examines the overpopulation problem in detail and explains how to prepare deer meat. At the Afan Woodland Trust, the conservation organization he heads in Kurohime, Nagano Prefecture, he also often hosts venison dinners in hopes of educating people through experience.

Meanwhile, the environmental group and organic-produce home-delivery service provider Daichi wo Mamaoru Kai (Association to Preserve the Earth) is also supporting the cause.

Daichi started selling venison during the winter months three years ago, and has recently begun a campaign to promote its consumption, so reducing the animals' impact on plant and other species. Their first event this month featured a venison dinner at the Wako French restaurant in Tokyo's glitzy Ginza district.

Daichi spokesperson Yukie Ohno says the association is planning more events for the future, including venison cooking programs and casual lunches. On Feb. 27, it will also host a discussion on the topic of deer and biodiversity issues at a farmers' market event in Tokyo's Ota Ward.

Some believe that deer meat has a strong odor and are reluctant to eat it. The reason, according to Ohno, is a simple lack of information.

"People don't know how delicious it is. Now we mostly eat beef, pork and chicken, though we've had venison for thousands of years," she says. "Venison is low in calories and high in iron. It's good for women and people who exercise."

Although Nicol never buys farmed meat to cook at home, he doesn't believe it's necessary to eat venison exclusively to have a significant impact on the problem. "We don't want everyone to start eating it on a regular basis. We just want to be able, through the sale of the venison, to pay those who control the numbers."

The first step, Kaji notes, is to recognize deer as a valuable natural resource — then to create policies and support industries that can sustain it. The solution, he insists, must take a holistic approach, because the problem itself is much bigger than it seems on the surface.

"The deer problem is not only one of ecosystems, it's about land conservation," he points out. "There are a lot of deer on the watersheds and to protect them the deer must be managed. It's a land problem."

"If you're eating venison, you are helping, and if it was taken by a hunter, the deer was free," says Nicol.

Venison is scarce at supermarkets, but it is readily available online through such Web sites as the following: The Meat Guy (English, Japanese) at www.themeatguy.jp/app/en/products/index/10 Daichi wo Mamoru Kai (from January to March, Japanese) at www.daichi.or.jp/ Kitaichi (Japanese) at www.kitaiti.com/ezoshika/ez4—shop.html Hokusen (Japanese) at www.hokusen-kk.com/momiji/ Shariken (Japanese) at www.shariken.co.jp/ezoshika/ Mori no Bazaar (Japanese) at morinobazaar.com/SHOP/370710/list.html