The Calayan Rail (Gallirallus calayanensis) is a flightless bird of the rail, moorhen, and coot family (Rallidae) that inhabits Calayan Island in the Philippines. Though well-known to natives of the island as the "piding", it was first observed by ornithologist Carmela Espaņola in May 2004 and the discovery officially announced on August 16, 2004. The formal description as a species new to science appeared in the journal Forktail (Allen et al. 2004).
The Calayan Rail is one of the 20 known extant flightless rails. It is small and dark brown, with a distinctive orange-red bill and legs, and utters loud, harsh calls. Its habitat seems to be restricted to forests on coralline limestone areas on Calayan and extends to a total of less than 100kmē. Biologists estimate that there may be 200 pairs on the island.
The Calayan Rail's genus, Gallirallus, includes many species of Southwest Pacific islands, of which the most familiar in the English-speaking world is the Weka of New Zealand. Its species name was derived from the name of the island.
Due to its recent discovery, little further information on this species is available at this time.