Niceforo’s Wren Thryothorus nicefori is currently listed as Critically Endangered under criterion C2a(i), based on the species having a population of fewer than 250 mature individuals, experiencing a continuing decline, with all sub-populations numbering 50 individuals or less.
Recent records have extended the species’s known range, and the Extent of Occurrence (EOO) is now estimated at 4,700 km2. In addition, a recent estimate for the total population put the number of mature individuals at 250; however, the accuracy of this estimate requires verification (S. Valderrama in litt. 2008, 2010).
BirdLife range map for Niceforo’s Wren
Robust evidence that the total population indeed numbers at least 250 mature individuals would evoke downlisting of the species to Endangered under criteria B1a+b(iii, v); C2a(i); D1, on the basis that it has a declining population numbering fewer than 1,000 mature individuals, occupying an EOO of less than 5,000 km2. Comments on the likely total population size would be welcomed.