# Masked Booby

Scientific name: Sula dactylatra

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

Canonical source: https://birdsofpuertorico.com/bird/146/Masked-Booby

## Identification

The masked booby (Sula dactylatra), also called the masked gannet or the blue-faced booby, is a large seabird of the booby and gannet family, Sulidae. First described by the French naturalist René-Primevère Lesson in 1831, the masked booby is one of six species of booby in the genus Sula. It has a typical sulid body shape, with a long pointed yellowish bill, long neck, aerodynamic body, long slender wings and pointed tail. The adult is bright white with black wings, a black tail and a dark face mask; at 75–85 cm (30–33 in) long, it is the largest species of booby. The sexes have similar plumage. This species ranges across tropical oceans, except in the eastern Atlantic and eastern Pacific. In the latter, it is replaced by the Nazca booby (Sula granti), which was formerly regarded as a subspecies of masked booby.
  Juveniles of subsp personata on Kure Atoll in the Hawaiian island chain

## Distribution and habitat

The Masked Booby occurs throughout the worlds tropical 
and subtropical oceans (Raffaele 
and others 1998). It is a very 
rare and local year-round resident in the West Indies, 
where known breeding areas 
include the southern Bahamas, 
Jamaica, Puerto Rico, the Virgin 
Islands, Anguilla, Antigua, and 
the Grenadines (Raffaele and 
others 1998). It is described 
as uncommon in Puerto Rico 
and has been documented 
near Culebra, Monito (Oberle 
2018), and Desecheo islands 
(McCandless 1958). It usually 
inhabits warm tropical waters 
out at sea (Oberle 2018), except 
when attending its nest (Raffaele 
and others 1998). The atlas 
fieldwork yielded a total of 10 
records within six hexagons or 1 
percent of the 479 total hexagons 
(see map). Of the six hexagons where this species was found, 
breeding met the atlas definition 
of confirmed in 50 percent 
(three) of the hexagons, while 
the species was observed in 50 
percent (three) of the hexagons 
but without evidence of breeding 
(see map).Masked Booby 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. 

## Breeding

Previously published reports indicate that the Masked Booby 
generally breeds from February 
to August (Oberle 2018) and 
occasionally during September 
(Raffaele and others 1998). This 
is a colonial species, and the 
nest usually consists of a scrape 
cushioned with a fine layer       137Masked Booby/Boba Enmascaradaof weeds or grasses, usually made on the ground in small 
rocky islands (Biaggi 1997) or 
near a cliff face (Raffaele and 
others 1998). Atlas results show 
that this species breeds mostly 
from February to April, and to 
a lesser extent also during July 
and October (see chart). Overall, 
the breeding activity peaks in 
March, and it takes place on 
small offshore islands within the 
subtropical dry forest life zone 
(see chart). Results show that this species breeds in coastal areas 
within the subtropical dry forest 
life zone (100 percent of the 
hexagons) (see table and map).

## Conservation

The global population trend of the Masked Booby has not 
been quantified or assessed, 
but the species is described as 
fairly common (Stotz and others 
1996), and it is currently listed 
as a species of least concern by the IUCN (BirdLife International 
2018). Locally, this species is not 
listed in any of the threatened 
categories of PRDNER and 
USFWS. In Puerto Rico, the 
Masked Booby has a protected 
habitat in land of 2 percent or 
1.5 km2 of the total area covered by the hexagons where evidence 
of breeding was found for this 
species (96 km2).

Photo: https://birdsofpuertorico.com/static/images/webp/in_146_Im0.png.webp

Distribution map: https://birdsofpuertorico.com/static/images/webp/in_146_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.