Calayan Rail Gallirallus calayanensis is currently listed as Vulnerable under criteria D1; D2, on the basis that its population numbers fewer than 1,000 mature individuals, and is restricted to a very small area such that it is prone to the effects of human activities or stochastic events, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period. Mapping of records and the Extent of Occurrence (EOO) by ISLA Biodiversity Conservation (2008) has allowed BirdLife to estimate the EOO at 68 km2. The occurrence of the species on only one small island means that it is considered to occupy one location. With this in mind, any evidence of a continuing decline either in its EOO, Area of Occupancy, area, extent or quality of habitat or number of mature individuals will warrant uplisting of the species under criterion B1a+b. Information is requested on the rate of habitat loss, prevalence of other threats and the species’s likely population trend.
Updated BirdLife range map for Calayan Rail
ISLA Biodiversity Conservation (2008) Establishing a Wildlife Sanctuary in Sitio Longog, Calayan Island. Technical Report. Calayan Rail Project II: Building Stakeholders Capacity to Conserve an Island-Endemic Species.