Birds
Inaccessible Island Rail
Laterallus rogersi · also called inaccessible rail
Slipping through dense tussock grass on a remote South Atlantic island that few humans ever manage to reach, an Inaccessible Island rail holds the record as the smallest flightless bird on Earth, protected for centuries by the very cliffs that make its home so hard to visit.
Overview
The Inaccessible Island rail, Laterallus rogersi, is the smallest flightless bird alive, confined entirely to grassland and coastal habitat on Inaccessible Island within the Tristan da Cunha group in the South Atlantic Ocean. Its record-holding tiny size, complete restriction to a single remote island, and survival owed largely to that island’s natural inaccessibility to introduced predators make it one of the most geographically unique and physically extreme birds found anywhere in the world.
Saved by difficulty itself
Where many flightless island birds were wiped out by predators introduced through human contact, the Inaccessible Island rail owes its continued survival to the very quality that gives its island home its name, a natural barrier of cliffs and rough seas that has kept invasive species away entirely.
Status
Vulnerable, with a stable population confined entirely to Inaccessible Island, a restriction that leaves the species inherently at risk despite currently healthy numbers.
Inaccessible Island Rail: common questions
Is the Inaccessible Island rail really the smallest flightless bird?
Yes, this species is the smallest flightless bird alive, weighing only a small fraction of what most other flightless birds weigh, a remarkable size record for a bird that has given up flight entirely.
Why is the Inaccessible Island rail found only on one island?
This species is confined entirely to Inaccessible Island, a small, remote island within the Tristan da Cunha group in the South Atlantic Ocean, and has survived as a flightless bird largely because the island's difficult access has kept it free of the introduced predators that doomed similar species elsewhere.
How did Inaccessible Island get its name?
The island takes its name from the steep cliffs and treacherous landing conditions that make it genuinely difficult to reach by boat, a natural barrier that has also happened to protect the rail named after it from many of the threats facing other flightless island birds.
Why is the Inaccessible Island rail considered Vulnerable despite a stable population?
This species is classified as Vulnerable primarily because its entire population is restricted to a single small island, meaning any future introduction of predators or major habitat disturbance could pose a serious risk to the species as a whole, despite its currently stable numbers.