Biro Island Subtropical Plant Community: A Living Treasure in Shibushi Bay
Rising from the sparkling waters of Shibushi Bay in Kagoshima Prefecture, Biro Island (枇榔島, Birōjima) stands as one of Japan's most remarkable natural sanctuaries. This small, uninhabited island — its entire surface blanketed in ancient subtropical vegetation — has remained virtually untouched by human hands for centuries. Designated as a Special Natural Monument of Japan, the Biro Island Subtropical Plant Community represents a rare window into the primeval landscape of southern Kyushu, offering visitors a glimpse of what this coastal region looked like long before modern civilization took hold.
Located approximately 4 kilometers offshore from Shibushi Port, the island sits near the center of Shibushi Bay and forms part of the Nichinan Coast Quasi-National Park. With a circumference of about 4 kilometers, an area of 17.8 hectares, and a highest point reaching 83 meters above sea level, Biro Island may be modest in size, but its ecological significance is extraordinary. The island's geological foundation consists of early Cenozoic sandstone and shale layers, providing a stable base upon which one of Japan's most pristine subtropical ecosystems has flourished.
Why Was It Designated a Special Natural Monument?
The plant community on Biro Island first received national recognition on March 3, 1921, when it was designated as a Natural Monument during the Taisho era. This initial designation acknowledged the island's outstanding botanical value. Then, on July 19, 1956, the Japanese government elevated its status to Special Natural Monument — the highest level of protection afforded to natural heritage sites in Japan. Only 75 sites across the entire country hold this prestigious designation.
Two key factors contributed to the exceptional preservation of Biro Island's vegetation. First, the island's small size and rugged terrain made it unsuitable for permanent human habitation, meaning it was never cleared for agriculture or settlement. Second, the presence of Biro Shrine (枇榔神社) on the island's northern slope — said to have been founded during the Wadō era (708–715 CE) — meant that the surrounding forest was protected as sacred shrine woods, and the cutting of trees was traditionally forbidden. These combined circumstances allowed the island's subtropical plant community to survive in a near-pristine state, making it one of the most representative examples of undisturbed primeval forest among Japan's coastal islands.
The Botanical Wonders of Biro Island
The island takes its name from the Biro tree — the Chinese fan palm (Livistona chinensis) — which dominates its appearance when viewed from the mainland. The southern slopes are home to a dense pure stand of these majestic palms, with individual specimens estimated to be 300 to 400 years old. Several thousand of these ancient trees form a striking palm forest that is rarely seen at this scale elsewhere in mainland Japan.
Beyond the iconic fan palms, the island harbors more than 180 species of subtropical and tropical plants, creating a multilayered forest of extraordinary botanical diversity. The northern slopes are covered in broadleaf evergreen forest, where enormous epiphytic plants and climbing vines drape themselves over towering trees. In the moist valleys and wetland areas, dense colonies of ferns blanket the ground, while species such as Mokutachibana (Ardisia sieboldii), Shiratama-kazura (Psychotria serpens), and Kuwazuimo (Alocasia odora) — a giant-leaved relative of taro — contribute to the lush, almost jungle-like atmosphere.
The island is also home to a remarkable diversity of insect life, with approximately 235 species recorded. This rich entomological community further demonstrates the health and integrity of the island's ecosystem.
Conservation Efforts: Protecting the Island's Ecosystem
Maintaining the ecological integrity of Biro Island requires ongoing conservation efforts. One notable challenge emerged in the 1990s when an invasive bamboo species called Tōchiku (Bambusa multiplex) was discovered growing aggressively on the island. By the time the problem was identified, the bamboo had reached heights of about 12 meters with stems around 8 centimeters in diameter — far larger than typical specimens — and thousands of culms were threatening to encroach on the precious Biro palm forest.
Beginning in 2006, a coordinated effort involving the Shibushi City Board of Education, the Ōsumi District Forest Office, and botanical experts undertook a comprehensive eradication program. Through twice-yearly cutting and removal campaigns conducted over many years, the invasive bamboo was progressively eliminated. By 2021, no Tōchiku specimens could be found on the island, and a 2024 survey confirmed that the eradication appears to have been successful — a testament to the dedication of local conservationists and the power of patient, sustained environmental management.
Biro Shrine and the Legend of Emperor Tenji
On the northern hillside of the island stands Biro Shrine (枇榔神社), a small but historically significant Shinto sanctuary. According to tradition, the shrine was established during the Wadō period (708–715 CE), making it over 1,300 years old. The shrine is associated with legends involving Emperor Tenji, the 38th emperor of Japan who reigned in the 7th century. These legends add a layer of cultural and spiritual significance to the island beyond its botanical importance.
The presence of the shrine played a crucial role in preserving the island's vegetation over the centuries, as the surrounding forest was revered as sacred grounds. Even today, the shrine remains an integral part of the island's identity, connecting its natural heritage with Japan's spiritual traditions.
Visiting Biro Island
Biro Island is an uninhabited island without regular ferry service, and access can be limited depending on conditions. The island's pier was damaged by typhoons in the past, and landing may not always be possible. Visitors interested in seeing the island should contact the Shibushi City Tourism Association or the Shibushi City Board of Education for the latest access information.
Even without landing on the island, its impressive silhouette — entirely covered in subtropical greenery — can be appreciated from several vantage points on the mainland. The Daguri Cape Observatory (ダグリ岬展望台) offers a particularly fine panoramic view of the island set against the expanse of Shibushi Bay. From this elevated lookout, approximately 40 meters above the water, visitors can clearly see the distinctive palm-covered profile of Biro Island and appreciate the broader landscape of the bay.
Nearby Attractions and Things to Do
The area surrounding Shibushi Bay offers a wealth of experiences for visitors who come to admire Biro Island and explore the wider region.
Daguri Cape Area
Daguri Cape (ダグリ岬) is part of the Nichinan Coast Quasi-National Park and features an amusement park with rides including a Ferris wheel offering panoramic bay views, a go-kart track, and a monorail. In summer, a seawater swimming pool with water slides opens for families. The Daguri Cape Beach is a beautiful stretch of white sand backed by subtropical vegetation, ideal for swimming and marine activities.
Shibushi Bay Daikoku Dolphin Land
Located in Shibushi Bay, this marine facility is the only place in Kyushu where visitors can swim with dolphins. Additional activities include natural rock pool fishing, penguin feeding, and interactive marine creature exhibits.
Shibushi Samurai District
The historic samurai residences of Shibushi, including the well-preserved Amamizu Family Traditional Garden, offer a quieter and more authentic alternative to Kagoshima's famous Chiran Samurai District. The neighborhood preserves Edo-period streetscapes with traditional gardens built on natural bedrock.
Homanji Temple and Daiji Temple
These historic Buddhist temples near Shibushi feature beautiful gardens that are particularly stunning during autumn when ginkgo and maple trees create vibrant displays of gold and red foliage. Daiji Temple is designated as a cultural property of Kagoshima Prefecture and houses notable Nio guardian statues.
Local Cuisine
Shibushi is known for its distinctive Maruchon Ramen — a local noodle specialty — as well as fresh seafood from Shibushi Bay. The region is also one of Kagoshima Prefecture's premier green tea producing areas, and visitors can enjoy tea tasting experiences at facilities such as Osumi Teanery.
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Q＆A
- Can I visit Biro Island directly?
- Biro Island is an uninhabited island without regular ferry service. The pier was damaged by past typhoons, so landing is not always possible. Please contact the Shibushi City Tourism Association for the latest access information. Alternatively, the island can be viewed beautifully from the Daguri Cape Observatory on the mainland.
- What is the difference between a Natural Monument and a Special Natural Monument?
- In Japan, Natural Monuments are sites of significant scientific or cultural value designated under the Cultural Properties Protection Act. A Special Natural Monument is an elevated designation reserved for those of exceptional national or international importance. As of recent counts, only 75 sites in Japan hold this top-tier status, and Biro Island's subtropical plant community is one of them.
- What is the best season to view Biro Island?
- Biro Island's subtropical vegetation remains green year-round, so there is no single "best" season. However, spring and autumn offer the most comfortable weather for exploring the Daguri Cape area and enjoying views of the island. Summer brings opportunities for beach activities at nearby Daguri Cape Beach. Winter tends to be mild in this subtropical region.
- How do I get to Shibushi to see Biro Island?
- Shibushi is accessible by car from Kagoshima Airport (approximately 1 hour 15 minutes) or from Kagoshima-Chuo Station (approximately 1 hour 30 minutes). The JR Nichinan Line serves the area, with Osumi-Natsui Station being the closest stop to the Daguri Cape viewpoint. Shibushi Port also offers ferry connections.
- Are there English-language resources available in the Shibushi area?
- While Shibushi is not a major international tourist destination, the city publishes a tourism guidebook called "Shibushi no Koto" in both Japanese and English. Major attractions like Daguri Cape and the Dolphin Land facility generally have basic English signage. For a smoother visit, consider downloading translation apps or contacting the Shibushi City Tourism Association in advance.
Basic Information
| Official Name | Biro Island Subtropical Plant Community (枇榔島亜熱帯性植物群落) |
|---|---|
| Designation | Special Natural Monument of Japan (国指定特別天然記念物) |
| Initial Designation | March 3, 1921 (Natural Monument) |
| Special Designation | July 19, 1956 (Special Natural Monument) |
| Location | Shibushi City, Kagoshima Prefecture (志布志市志布志町帖) |
| Geographic Position | Approximately 4 km offshore in Shibushi Bay |
| Island Circumference | Approximately 4 km |
| Area | 17.8 hectares |
| Highest Elevation | 83 meters |
| Plant Species | Over 180 subtropical species |
| Insect Species | Approximately 235 species recorded |
| Geology | Early Cenozoic sandstone and shale layers |
| Park Designation | Nichinan Coast Quasi-National Park |
| Nearest Viewpoint | Daguri Cape Observatory (ダグリ岬展望台) |
| Access | Approximately 30 minutes by boat from Shibushi Port (service not regularly scheduled) |
References
- 【国指定文化財】 枇榔島亜熱帯性植物群落 - 志布志市公式ホームページ
- https://www.city.shibushi.lg.jp/soshiki/22/1492.html
- 枇榔島亜熱帯性植物群落 - 鹿児島県立博物館
- https://www.pref.kagoshima.jp/bc05/hakubutsukan/tennen/kuni_tokubetu/06birojima.html
- 枇榔島亜熱帯性植物群落 - 文化遺産オンライン
- https://bunka.nii.ac.jp/heritages/detail/164201
- 枇榔島（ビロウジマ） – 志布志市観光特産品協会
- https://www.sibusi-k-t.jp/%E6%9E%87%E6%A6%94%E5%B3%B6%EF%BC%88%E3%83%93%E3%83%AD%E3%82%A6%E3%82%B8%E3%83%9E%EF%BC%89/
- 枇榔島 (鹿児島県) - Wikipedia
- https://ja.wikipedia.org/wiki/%E6%9E%87%E6%A6%94%E5%B3%B6_(%E9%B9%BF%E5%85%90%E5%B3%B6%E7%9C%8C)
- 枇榔島亜熱帯性植物群落 - かごしま文化財事典プラス
- https://k-bunkazai.com/cultural/d-o-40102/
- 無人の枇榔島でなぜか繁殖した侵入植物「トウチク」 - 南日本新聞
- https://373news.com/news/local/detail/206362/
Last verified: 2026.03.02