Assessing the extent of occurrence, area of occupancy, territory size, and population size of marsh tapaculo (Scytalopus iraiensis)

Abstract

First described in 1998, the marsh tapaculo (Scytalopus iraiensis) is an endangered bird of the family Rhinocryptidae. It is endemic to Brazil and is restricted to the wet flood plains of rivers and streams. Due to its cryptic habits and environments of occurrence, information available on its biology, natural history and distribution is scarce. We compiled occurrence records (99 records), delimited the extent of occurrences (296,584 km²), calculated the area of occupancy (84 km²), estimated territory size (5,313 ± 1,201 m² per pair), population density (3.76 ± 0.85 individuals per hectare), and population size (31,584 ± 7,140 mature individuals) of marsh tapaculo. The species was recorded in marshes associated to four types of vegetation and in four ecological zones. This new information is extremely important to support revaluation of the species’ threat category and to enhance knowledge about this endemic and little known bird from Brazil.