# Masked Duck

Scientific name: Nomonyx dominicus

Bird group: [duck](https://birdsofpuertorico.com/family/duck)

Canonical source: https://birdsofpuertorico.com/bird/42/Masked-Duck

## Identification

The masked duck (Nomonyx dominicus) is a tiny stiff-tailed duck ranging through the tropical Americas. They are found from Mexico to South America and also in the Caribbean. Primarily not migratory, masked ducks are reported as very uncommon vagrants in the southernmost United States, along the Mexican border and in Florida. As of 2000, the conservation status for masked ducks in Texas is 3,800 birds. On April 1, 1962, it was recorded from Lowndes County, Georgia, where it was photographed by Alexander Wetmore.


## Distribution and habitat

The Masked Duck is a rare resident in Puerto Rico (Oberle 
2018, Raffaele and others 1998) 
and a rare visitor in Vieques 
(Gemmill 2015). The atlas 
fieldwork yielded a total of 20 
records within 11 hexagons or 2 
percent of the 479 total hexagons 
(see map). Of the 11 hexagons 
where this species was found, 
breeding met the atlas definition 
of confirmed in 18 percent (two) 
of the hexagons, probable in 9 
percent (one), and possible in 
73 percent (eight) (see map). 
This species inhabits freshwater 
swamps and canals with plenty of fl oating vegetation, as well as 
rice fields (Raffaele and others 
1998), brackish water ponds, and 
lagoons (Oberle 2018). 

## Breeding

Previously published reports indicate that the Masked Duck 
breeds from May to August and 
nests on swamp vegetation near 
or over the water (Raffaele and 
others 1998). Atlas results show 
that the Masked Duck breeding 
season extends throughout the 
year, but the most records were 
reported in June (see chart). 
Results show that the Masked 
Duck mostly breeds within the Masked Duck 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.      33Masked Duck/Pato Dominicosubtropical moist (73 percent of the hexagons) and subtropical 
dry forest life zones (27 percent 
of the hexagons) (see table 
and map). 

## Conservation

The Masked Duck population is suspected to be declining 
owing to over-hunting and 
other human pressure but is 
listed by the IUCN as a species 
of least concern (BirdLife 
International 2016). The Puerto 
Rican population is composed of around 50 pairs and is 
under pressure from illegal 
hunting and habitat degradation 
associated with human activities 
(J.A. Salguero-Faría, personal 
observation 2009). In Puerto 
Rico, the Masked Duck is listed 
as endangered (PRDNER 2016) 
and has a protected habitat in 
land of 15 percent or 39 km2 of the total area covered by 
the hexagons where evidence 
of breeding was found for this 
species (264 km2). 

Photo: https://birdsofpuertorico.com/static/images/webp/in_042_Im0.png.webp

Distribution map: https://birdsofpuertorico.com/static/images/webp/in_042_Im1.png.webp

Source note: Text is reproduced from this site's published record. Historical conservation statements and taxonomy have not been independently revalidated. See https://birdsofpuertorico.com/about for source credits and limitations.