The clapper rail (Rallus crepitans) is a member of the rail family, Rallidae. The taxonomy for this species is confusing and still being determined. The Ridgway's rail (formerly the California clapper rail) and the mangrove rail have been recently split. Furthermore, some taxonomists consider that the King rail and Aztec rail should be considered within this group, as those birds look similar and the birds are known to interbreed where they share territories. The clapper rail is a chicken-sized bird that rarely flies. It is grayish brown with a pale chestnut breast and a noticeable white patch under the tail. Its bill curves slightly downwards.
The Clapper Rail occurs from the coastal United States south through South America including the West Indies (Raffaele and others 1998). It is a locally common resident in Puerto Rico (Raffaele 1983), especially on mangroves and salt fl ats along the coast (Oberle 2018, Raffale 1989a), and fairly common in Vieques (Gemmill 2015). The Clapper Rails habitat includes mostly salt marshes, mangroves (Raffaele and others 1998), and mudfl ats (Oberle 2018). It also occurs in pairs or small groups on offshore mangrove cays (J.A. Salguero-Faría, personal observation 2009). The atlas fieldwork yielded a total of 86 records within 55 hexagons or 11 percent of the 479 total hexagons (see map). Of the 55 hexagons where this species was found, breeding met the atlas definition of confirmed in 5 percent (3) of the hexagons, probable in 20 percent (11), and possible in 75 percent (41) (see map). Clapper Rail distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding.
The Clapper Rail builds a platform nest of sticks among mangrove roots, and breeding season extends from April to 91Clapper Rail/Pollo de MangleMay, according to previously published reports (Raffaele and others 1998). Atlas results indicate that the breeding season for this species extends throughout the year and peaks in May (see chart). Results show that this species is confined to the coast and breeds within the subtropical dry and subtropical moist forest life zones (73 and 27 percent of the hexagons, respectively), and it is closely associated with mangroves (e.g., note abundance of south and southwest coastal records in contrast to the north coast where mangroves are patchy, with the exception of Piñones, east of San Juan) (see table and map).
Overall, Clapper Rail population trends are decreasing worldwide due to habitat loss, but it is listed as a species of least concern by the IUCN (BirdLife International 2016). Locally, this species is not listed under any of the threatened categories. In Puerto Rico, the Clapper Rail has a protected habitat in land of 13 percent or 169 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (1315 km2).