Small
size [58-73 cm (23-29 inches) in length], long tail, and
yellowish throat patch should distinguish it from other cormorants in
the region. In adults and immatures this throat patch is thinly
bordered with white. Often seen in small flocks. Plumage varies between
juveniles, immatures and adults. Voice: guttural, pig-like grunts.
Adults know to live for at least 12+ years.
Adults
Throat
pouch smaller, pale yellowish-brown in color with white
border and ‘v’ shaped in comparison to that of Double-crested
Cormorant. Tail proportionally longer than Double-crested. White tufts
on sides of head.
Juveniles
Totally
brown, lacks white border to gular pouch; immatures
have suggestion of gular pouch border, underparts, including neck light
off white. Tufts on sides of head lacking.
Alternative Names
The
Neotropical Cormorant, P.
brasilanus is the currently
accepted name, but this bird appears as the Olivaceous Cormorant, P.
olivaceus, in many recent publications.
This
cormorant probably constitutes a superspecies with the Double–crested
Cormorant with which it is marginally sympatric. The northern
portion of the West Indies region is one such area of overlap. Two
subspecies recognized. P.
b. mexicanus occurs in southern United
States, Central America and the Bahamas and Cuba.
Likely locations
Coastal
areas
throughout region, as breeding species primarily in Bahamas and US
Virgin Islands. Typically feeds inshore but can forge far at sea.
Distribution
For
the most part a freshwater South American species with estuarine
populations adjacent to coastal areas along northern South American
coast, Central America, and the upper Gulf of Mexico north and east to
Texas and Louisiana. Also in Cuba and the Bahamas. Non-migratory to
short-range migrant in upper Gulf of Mexico. This is not primarily a
marine species.
In
West Indies region, known to breed in the Bahamas (San Salvador, Cat
Island,
and Great Inagua) and Cuba (Isle of Youth); wanders to Dominican
Republic, Jamaica, and Puerto Rico.
Biology
At
sea
Not
a marine species but adaptable and found in brackish and
marine habitats. In coastal sites remains inshore, mostly sheltered
bays and inlets. Not migratory. Feeds by pursuit diving, but unlike all
other cormorants also by plunge-diving. Feeds mostly on small (18-230
mm) shallow water fish.
At
the nest
Information
from studies outside the region.
Colonial with a course platform of sticks for the nest. Typically 2-4
light sky blue
eggs, with chalky white deposits. Incubation period 22-26 days. Begin
swimming and diving near colony at 8 weeks, parental care continues for
11 weeks. Independent by 12th week. Young or adults will occasionally
disperse up to 65 km from breeding colony
Current Population
Total
global population unknown. US population has
fluctuated in recent decades; 3,000 pairs in Louisiana and 500 pairs in
Texas (Clapp and Buckley 1984) but estimated later at 16,000
individuals [less than 8,000 pr.] (Kushlan et al 2002). Currently
expanding.
Cuban
populations have increased in recent decades probably as a result of
fish farming and rice plantations. This may account for increased
number of reports for other West Indies islands. Size of West Indian
breeding populations unclear, but populations are not large and
probably fewer than several 1,000 pr.
Area
Estimate
Source
Louisiana
3000-6000
Clapp
and Buckley 1984; Kushlan et al. 2002
Texas
500-2000
Clapp
and Buckley 1984; Kushlan et al. 2002
Bahamas
<1000
Cuba
<1000
Total
~10000
Conservation Status
Continentally,
this is a common species in freshwater and
estuarine habitats and excluding local peripheral populations it is not
a species of conservation concern. Increasing in numbers and
distribution in southern United States and to some extent in Cuba, but
remains relatively uncommon in West Indies region.
Conservation Needs
Tolerant
to a wide variety of aquatic habitats, and to
vehicular traffic, boating, and fishing. Cuban population expanding;
exploits reservoirs and fish farms. Is intolerant of close approaches
to nest. No obvious current conservation needs. This bird’s limited
dispersal simplifies implementing any needed local conservation
initiatives This species remains largely unstudied (except for
interactions with fish farms in US) and no known surveys or studies
within West Indies. Studies of Cuban and Bahaman breeding population
are warranted.
Photos
Selected References
Clapp,
R. B. and P. A. Buckley 1984. Status and conservation of seabirds in
the Southeastern United States. Pages
135-155 in J. P. Croxall, P. G.
Evans and R. W. Schreiber (eds). Status and Conservation of the World’s
Seabirds. ICBP Tech. Publ., No. 2. 778 p.
Kushlan,
J.A. et al. 2002. Waterbird Conservation for the Americas: The North
American Waterbird Conservation Plan, Version I. Waterbird Conservation
for the Americas, Washington, DC. 78 p.
Telfair,
R. C. II and M. L. Morrison. 1995. Neotropical Cormorant (Phalacrocorax
brasilianus). In The Birds of North America, No 137 (A.
Poole and F.
Gill, eds.). The Academy of Natural Sciences, Philadelphia, and The
American Ornithologists’ Union, Washington, D.C.
Compiled
by: Dave Lee and Will Mackin
West
Indian Breeding Seabird Atlas by Will
Mackin and David Lee is licensed
under a Creative
Commons Attribution-Noncommercial-No Derivative Works 3.0 United States
License. Based on
work at www.wicbirds.net.
Permissions beyond the scope of this license may be available at www.wicbirds.net.
Suggested
Citation: Lee, D. S., W. A. Mackin. 2009. Neotropic Cormorant. West Indian
Breeding Seabird Atlas
<http://www.wicbirds.net/neco.html>. Last Updated: _____.
Date accessed: ______.
