Zapata Rail - Conservation Status

Conservation Status

Island species of rails are particularly vulnerable to population loss since they frequently and rapidly evolve to become flightless or very weak fliers, and are very susceptible to introduced predators. Fifteen species have become extinct since 1600, and more than 30 are endangered.

The Zapata Rail appears to have been easily found in the Santo Tomás area until 1931, but there were no further records until the 1970s when birds were found 65 km (40 mi) away at Laguna del Tesoro. The few records in subsequent years suggest that numbers remain low, although after no official sightings for two decades, a 1998 survey found the birds at two new locations in the Zapata Swamp. Ten rails were detected at Peralta, and seven at Hata de Jicarita. On the basis of this sample it was estimated that 70–90 rails were present in the 230 hectares (570 acres) between the two sites.

The Zapata Rail is restricted to a single area, with an extent of about 1,000 km2 (400 mi2), and its small population, estimated on the basis of recent surveys and local assessments of population densities at between 250–1000 individuals, is assessed as decreasing. In the past, grass-cutting for roof thatch was a cause of extensive loss of breeding habitat, and habitat loss through dry-season burning of the vegetation continues. Predation by introduced Small Asian Mongooses and rats is a problem, and more recently, introduced African Sharptooth Catfish, Clarias gariepinus, have been identified as a major predator of rail chicks.

The Zapata Rail was classified as an endangered species on the IUCN Red List until 2011, when its status was uplisted to critically endangered. This had already been suggested, since given the lack of knowledge about its calls, the rail's population may be lower than currently estimated.

Two remaining sites are in protected areas, the Corral de Santo Tomás Faunal Refuge, and the Laguna del Tesoro nature tourism area. Surveys have recently been conducted throughout the species' range and proposed conservation measures include the control of dry season burning.