Hokkaido's estimated sika deer population stands at roughly 720,000. Forestry damage is among the worst in Japan, and annual culls have held at around 140,000 head. Drawing on the ten-year trends in deer density and damage costs across Dohoku (northern Kamikawa, the Soya mountains, and the inland Rumoi area), this article documents the design logic behind deer fences (net-type, electric, and modular) alongside the on-the-ground practice in Shimokawa and Nakagawa, where the chain from culling to meat processing is built up entirely within the region, recording it as a meeting point of fieldwork and data.
Hokkaido’s estimated sika deer population is roughly 720,000 (FY2023 estimate), about three times the figure from twenty years ago. The impact on vegetation is severe across forest saplings, farmland crops, and native grassland plants, and forestry damage in Hokkaido has, year after year, accounted for more than half of the national total. This article organizes the trends in deer density across Dohoku (northern Kamikawa, the Soya mountains, and the inland Rumoi area), the design of fence-centered control measures, and the practice of nbyn members such as Mato Shibuya and Yuto Urabe, who build the entire chain from culling to meat processing within the region, treating it as an intersection of field and data. For prefecture-wide numerical trends, see the related dohokuhub issue.
1. The Current Situation in Numbers
| Indicator | Value | Source |
|---|---|---|
| Estimated population (2023) | approx. 720,000 head | Hokkaido Sika Deer Management Plan |
| Annual cull (2023) | approx. 143,000 head | Hokkaido Sika Deer Cull Statistics |
| Forest damage area (national / Hokkaido share) | approx. 50% | Forestry Agency, Forest Damage |
| Agricultural and forestry damage cost (Hokkaido, 2023) | approx. 4.5 billion yen | MAFF, Wildlife Damage |
| Aging rate among cull workers | about 70% aged 60 or over | Ministry of the Environment, Wildlife Statistics |
The deer problem cannot be confined to “a matter of forests and farmland.” By devouring forest saplings and understory vegetation, deer set off a chain reaction that reaches all the way to soil water retention, bird nesting sites, and the genetic diversity of native plants. Rather than assessing the impact of a single animal on a flat, two-dimensional basis, we need to read it as a system.
2. What Makes Dohoku Distinctive
Dohoku has deep winter snowpack, and deer tend to concentrate in low-elevation valley bottoms, river terraces, and snowbreak forest belts. As a result:
- The boundary between farmland and forest becomes a hotspot of uneven deer density.
- Riparian forests along the Teshio, Nayoro, and Sanru rivers function as overwintering grounds in winter, with deer dispersing to surrounding forests and farmland in summer.
- Roadkill on roads and railways concentrates in early spring (March to May).
For this reason, control in Dohoku is more realistic when designed to “block movement corridors” rather than to “enclose by area.” Fence placement is determined by back-calculating the deer’s seasonal migration routes from terrain and vegetation.
3. Fence Types and Cost-Effectiveness
Here we organize the main deer fences in use in Dohoku by purpose.
3.1 Permanent Net-Type Fences
The most standard type, stretching polyethylene or stainless-steel mesh to a height of around 2 meters. Deployed over wide areas along roads and farmland.
- Installation unit cost: approx. 2,000–3,500 yen / m
- Service life: 10–15 years
- Maintenance: annual repair of fallen trees, snow-load damage, and collapse required
3.2 Electric Fences (Pulse Fences)
Wires carrying low voltage are strung in 2–3 tiers; the mainstay on farmland.
- Installation unit cost: approx. 700–1,500 yen / m
- Service life: 5–8 years
- Maintenance: mowing and battery/solar inspection required (weekly during the season)
3.3 Modular Fences (Sawtooth / Folding-Screen Type)
A lightweight type that can be bent and installed to fit the terrain. Increasingly used along riverbanks and trails. It exploits the fact that deer are poor at leaping diagonally, blocking their approach with a zigzag plane rather than a flat one.
- Installation unit cost: approx. 3,000–5,000 yen / m (including terrain adjustment)
- Service life: 15–20 years
- Maintenance: chiefly inspection of the folded sections
3.4 Protection Targets and Cost Sense
| Target to protect | Recommended fence type | Cost band |
|---|---|---|
| Large-scale farmland | Electric + net-type | Medium |
| Forestry planting sites | Net-type (high durability) | Medium–High |
| Single trees (important trees) | Trunk-wrap type | Low |
| Riverbanks / trails | Modular | Medium–High |
| Nature-observation areas | Modular + signage | High |
In Dohoku municipal forests, there is a growing number of cases where permanent net-type fences are deployed in lengths of 2 km to 5 km on a forest-compartment basis, in order to intensively protect young stands 5 to 10 years after planting.
4. Implementation Cases in Dohoku
4.1 Shimokawa: In-House Wildlife Control and Meat Processing
Since the 2010s, Shimokawa has cultivated a system in which a town-run wildlife control team works together with the hunting association and meat-processing operators to complete the chain from culling to sanitary processing to distribution within the region. Mato Shibuya served as a wildlife control support officer in the Industrial Promotion Division of the Shimokawa town office from 2023 to 2026, and now, having moved to the meat-retail side at Largo Co., Ltd. (Kitatsumugi Shoten / Niku no Kikuchi), supports this loop from both ends.
4.2 Nakagawa: Turning Venison into Local Cuisine
In Nakagawa, Yuto Urabe (a graduate of Rakuno Gakuen University and a regional revitalization cooperation corps member) has launched a business that single-handedly runs the whole chain of culling, butchering, sales, and cooking. At events, by cooking and serving the sika deer he has caught himself, he translates the “deer problem” from a management challenge into a conversation about the region’s dinner table.
4.3 Nakagawa: Linking with Forestry
Nakagawa’s promotion corporation (in charge: Shunya Izumi) is piloting a framework that lets tourists experience forests and the deer problem, linked with tourism-based community development, hometown tax (furusato nozei), and specialty-product development. A package bundling hunting experiences, game cuisine, and forest guiding also functions as a mechanism for redistributing revenue among operators within the region.
5. Seeing the Deer Problem as a System
When control, culling, distribution, and turning game into food are connected as a “line,” the resolution of the deer problem changes.
| Stage | Who carries it | Required assets |
|---|---|---|
| Monitoring | Prefectural government, universities, local observers | Population surveys, sensor cameras |
| Control (fences, repellents) | Municipalities, foresters, farmers | Fences, maintenance, subsidies |
| Culling | Hunting associations, wildlife control support officers | Guns, traps, training of personnel |
| Sanitary processing | Meat-processing facilities | HACCP equipment, primary-processing personnel |
| Distribution | Butchers, restaurants, e-commerce | Cold chain, branding |
| Turning into food | Restaurants, chefs, media | Recipes, narrative, consumer education |
What is rare in Dohoku is that much of this six-stage chain can be built in-house within a single municipality (Shimokawa and Nakagawa). This is an attempt to rebuild the work not as “countermeasures” but as an “industry,” and it could become a reference model for wildlife management nationwide.
6. What Will Happen in the Next Decade
- Within TNFD compliance, deer damage becomes subject to disclosure as a “nature-related risk.” Major forestry, lumber, and food companies will begin building the wildlife-control costs of their supply sources into their evaluation metrics.
- With the spread of AI / IoT sensor cameras, the granularity of population monitoring shifts from the current annual basis to a monthly or weekly one. Fence inspection and repair will also be optimized in a data-driven way.
- Branding of game meat. Food brands tied to place name, sanitation, and narrative—such as “Dohoku Sika Deer” or “Shimokawa-Nakagawa wild meat”—will achieve stable distribution in Tokyo-area restaurants and e-commerce.
- Generational handover of personnel. Whether a handoff can be designed from today’s cull-worker cohort, centered on those in their sixties and older, to younger people, in-migrants, and women hunters will be the single greatest issue for the system’s sustainability.
For Deeper Reading
- dohokuhub Issue “Conserving Biodiversity and Ecosystem Services” — prefecture-wide arguments on biodiversity
- dohokuhub Issue “Brown Bears and the Challenge of Human Coexistence” — a framework for coexistence with large mammals (adjacent to the deer problem)
- nbyn Magazine “Dohoku’s Forest System: A Decade of Trends Traced Through Census Data” — the forest-side companion piece to this article
Sources
- Hokkaido Sika Deer Management Plan
- Forestry Agency Forest Damage
- MAFF Wildlife Damage
- Ministry of the Environment Wildlife Statistics
- Hokkaido Research Organization Sika Deer Research
- Shimokawa Town Wildlife Control