# Sooty Tern

Scientific name: Onychoprion fuscatus

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

Canonical source: https://birdsofpuertorico.com/bird/126/Sooty-Tern

## Identification

The sooty tern (Onychoprion fuscatus) is a seabird in the family Laridae. It is a bird of the tropical oceans, returning to land only to breed on islands throughout the equatorial zone.
  O. f. nubilosus flying on Rodrigues Island in the Indian Ocean

## Distribution and habitat

The Sooty Tern occurs through the tropical oceans of the world 
(Oberle 2018, Raffaele and others 
1998). In the West Indies, it is 
generally a common breeding 
resident from May to August 
(Raffaele and others 1998). It is 
fairly abundant in Puerto Rico 
during the summer months 
(Biaggi 1997), and it can be seen 
on the nesting colonies in Mona, 
Monito, and Culebra, as well as 
the Cordillera Natural Reserve 
(Oberle 2018). It is also found on 
Vieques, where it is considered 
an extremely rare summer visitor (Gemmill 2015). It mostly 
occurs far offshore (Raffaele 
and others 1998), except when 
nesting (Oberle 2018). The atlas 
fieldwork yielded a total of 24 
records within 14 hexagons or 3 
percent of the 479 total hexagons 
(see map). Of the 14 hexagons 
where this species was founds, 
breeding met the atlas definition 
of confirmed in 43 percent (six) 
of the hexagons and possible 
in 7 percent (one), while the 
species was observed in 50 
percent (seven) of hexagons but 
without evidence of breeding 
(see map).Sooty Tern 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.       117Sooty Tern/Charrán Oscuro

## Breeding

Previously published reports indicate that the Sooty Tern 
breeds from April to August 
(Raffaele and others 1998). The 
nest is a scrape made on coral 
rubble or below overhanging 
vegetation, mostly in large and 
gregarious colonies (Raffaele 
and others 1998). Atlas results 
show that this species breeds 
from March to July (see chart). 
The breeding activity peaks 
in June and takes place in 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 current overall population trend of the Sooty Tern is 
described as unknown, as some 
of the populations are decreasing 
and others are increasing or 
have unknown trends (Delany and Scott 2006). This species 
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 Sooty 
Tern has a protected habitat in 
land of 2 percent or 3 km2 of the total area covered by the 
hexagons where evidence of 
breeding was found for this 
species (167 km2).

Photo: https://birdsofpuertorico.com/static/images/webp/in_126_Im0.png.webp

Distribution map: https://birdsofpuertorico.com/static/images/webp/in_126_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.