The Okinawa rail is a species of bird in the rail family, Rallidae. It is endemic to Okinawa Island in Japan where it is known as the Yanbaru kuina . Its existence was only confirmed in 1978 and it was formally described in 1981 although unidentified rails had been recorded on the island since at least 1973 and local stories of a bird known as the agachi kumira may refer to this species. The species was formerly placed in the genus Hypotaenidia.
Region
Ryukyu Islands (northern Okinawa Island)
Typical Environment
Confined to the subtropical evergreen broadleaf forests of northern Okinawa, especially dense understory along valleys and stream gullies. It favors thick ground cover for foraging and cover, using forest edges and secondary growth as well. Rails will also venture to roadside verges and small clearings, particularly at dawn and dusk. Nesting and most daily activity occur within intact forest blocks close to water and moist leaf litter.
Altitude Range
Sea level to 500 m
Climate Zone
Subtropical
Ease of Keeping
Beginner friendly: 1/5
Known locally as the Yanbaru kuina, the Okinawa rail was only confirmed to science in 1978 and described in 1981. It is almost flightless and often seen dashing across forest roads, which makes roadkill a significant threat. Intensive control of introduced mongooses has helped the population recover locally, but habitat loss and feral predators still pose risks.
Stuffed specimen of Hypotaenidia okinawae at the National Museum of Nature and Science, Tokyo, Japan.
Temperament
secretive yet sometimes bold near roads
Flight Pattern
mostly flightless; runs with short fluttering hops
Social Behavior
Typically found in pairs or small family groups and strongly territorial during the breeding season. Nests are placed on or near the ground in dense vegetation, with both adults involved in care. Chicks are precocial and follow adults soon after hatching.
Migratory Pattern
Resident
Song Description
Vocal, especially at dawn and dusk, giving loud, piercing squeals and repeated kek-kek or kiiin notes. Duetting between pair members is common and can carry far through the forest.
Plumage
Dark brown to olive-brown upperparts with bold black-and-white barring on the flanks and underparts; very short, rounded wings. The head and breast are dusky to blackish with contrasting pale facial markings.
Diet
Forages mainly on invertebrates such as earthworms, beetles, insects, spiders, and snails. It also takes small vertebrates like frogs and lizards when available and occasionally consumes seeds, berries, and fallen fruit. Food is gleaned from leaf litter, soft soil, and along stream margins.
Preferred Environment
Feeds on the forest floor in dense understory, along wet gullies, and near small streams. It may also use edges of tracks and roads where prey is easier to spot, retreating quickly to cover when disturbed.
