Masked Duck Nomonyx dominicus


Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size could fall within a wide range from moderately small to very large, but it is not thought to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Population justification
Partners in Flight estimate the total population to number 200,000 mature individuals (Partners in Flight 2019, see also Panjabi et al. 2019). However, Wetlands International (2019) have placed the population at 25,000-100,000 individuals, roughly equivalent to 16,000-70,000 mature individuals. The species is poorly known, and given this uncertainty the extreme values are used and the population is placed in the range 16,000-200,000 mature individuals.

Trend justification
This species is tentatively suspected to be stable (per Partners in Flight 2019, Wetlands International 2019).


Text account compilers
Ekstrom, J., Hermes, C., Butchart, S., Westrip, J.R.S.

Recommended citation
BirdLife International (2022) Species factsheet: Nomonyx dominicus. Downloaded from on 17/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 17/08/2022.