Biro Island is an uninhabited island floating in the Hyuga-nada Sea off Kadogawa Town, Higashiusuki District, Miyazaki Prefecture. Its name comes from the birow palm trees that once grew abundantly on the island. According to an old legend, a beautiful woman once lived there, which is why local people also call it “Beautiful Woman Island” or “Bijoga-shima.” Rich in natural attractions, the island is known as a destination for recreational activities such as fishing and birdwatching.
Biro Island lies approximately 6 kilometers offshore from Kadogawa Bay. It is a small uninhabited island with an area of 4.12 hectares and a coastline of approximately 1.5 kilometers. The entire island is part of Nippo Coast Quasi-National Park.
One of its most distinctive geological features is its steep cliffs, formed by columnar joints associated with underwater volcanic activity. These dramatic rock formations create an impressive natural landscape that attracts visitors.
An old legend tells that when Emperor Jimmu’s fleet attempted to attack a whale, the whale transformed into a beautiful woman and pleaded for its life. This story is said to be the origin of the island’s alternative name, “Bijoga-shima,” or “Beautiful Woman Island.” The legend adds to the mysterious atmosphere surrounding the island.
Biro Island is nationally famous as the world’s largest breeding ground for the Japanese murrelet, a bird designated as a National Natural Monument of Japan.
During winter, Japanese murrelets live offshore. When the breeding season arrives, they move south and gather on Biro Island to nest in groups. They build their nests on the cliffs and slopes of rocky coastlines. One of the species’ remarkable characteristics is the way newly hatched chicks roll down the cliffs to reach the sea.
In addition to Japanese murrelets, Biro Island is known as a habitat for various other wild birds, including Styan’s grasshopper warblers and Japanese wood pigeons. The island’s rich natural environment attracts many different bird species every year, making it an excellent destination for birdwatchers.
Whales and dolphins have also occasionally been spotted in the waters around Biro Island. Visitors may be fortunate enough to see these graceful marine animals. The surrounding sea is a rich habitat for marine life, making the area particularly appealing to nature enthusiasts.
Biro Island is widely known as a premier destination for rock fishing. The surrounding waters are influenced by the Kuroshio Current, which creates favorable conditions for fishing and attracts many anglers.
The area is particularly popular for fishing species such as groupers and threeline grunts. Both beginners and experienced anglers can enjoy fishing here.
To enjoy rock fishing on the island, visitors take a fishing boat from Iori Fishing Port in Kadogawa Town. The boat journey takes approximately 20 minutes.
During the trip, anglers can enjoy the beautiful surrounding scenery. The island’s towering cliffs offer dramatic views rarely seen elsewhere, making the area attractive not only for fishing but also for landscape photography.
Visitors reach Biro Island by taking a boat from Iori Fishing Port in Kadogawa Town. The port is approximately a five-minute drive from JR Kadogawa Station, making it convenient to reach from the railway station.
The boat journey to the island takes approximately 20 minutes. Advance reservations and confirmation of weather conditions are necessary, but the island can be reached relatively easily when conditions permit.
As part of Nippo Coast Quasi-National Park, Biro Island is surrounded by other sightseeing destinations. Visitors can use Kadogawa Town or Hyuga City as a base and combine a visit to the island with trips to nearby attractions.
The beautiful waters of the Hyuga-nada Sea also provide opportunities to enjoy scenic drives and hiking in the surrounding area.
The Japanese murrelet is a rare seabird whose breeding has been confirmed in only a limited number of locations in Japan.
It is a small bird measuring approximately 24–25 centimeters in total length, with a wing length of 12.3 centimeters and a body weight of approximately 164 grams. During its summer plumage, the feathers on the crown of its head grow approximately 3–5 centimeters long, forming a distinctive feature known as a crest.
The bird mainly feeds on fish, but it also eats crustaceans and plankton.
Japanese murrelets arrive at Biro Island, their breeding ground, in December. They build their nests on cliffs and slopes along the rocky coast.
After hatching, the chicks leave their nests within one to two days. Responding to calls from their parents, they roll down the cliffs and make their way toward the sea. This unusual behavior is one of the remarkable natural phenomena associated with the species.
However, the population has been declining due to predation by rats and crows, as well as the effects of human marine recreational activities.
Biro Island is home to many wild animals, including the Japanese murrelet. However, fishing and marine recreational activities have raised concerns about people landing in breeding areas and damaging the birds’ habitat.
Other problems include discarded garbage that attracts predators and the accidental capture of birds in set fishing nets.
To address these threats, the Japanese government has designated the Japanese murrelet’s breeding grounds as a national wildlife protection area and is promoting conservation activities.
Biro Island is a mysterious uninhabited island where rich natural scenery, rare wildlife and ancient legends come together. Visitors can appreciate its natural beauty while enjoying outdoor activities such as rock fishing and birdwatching.
Although tourism development is being considered, conservation activities are also underway. It is important to enjoy the island in a way that allows people and nature to coexist, while protecting its valuable environment for future generations.
Biro Island offers a rare opportunity to experience the natural wonders of the Hyuga-nada Sea and learn about the wildlife that depends on this special island.