Neotropic Cormorant
Encyclopedia
The Neotropic Cormorant or Olivaceous Cormorant (Phalacrocorax brasilianus) is a medium-sized cormorant
found throughout the American tropics and subtropics, from the middle Rio Grande
and the Gulf and California
n coasts of the USA south through Mexico
and Central America
to southern South America
. It also breeds on the Bahamas, Cuba
and Trinidad
. It can be found both at coasts (including some mangrove areas) and on inland waters. There are at least two subspecies
: P. b. mexicanus from Nicaragua
northwards and P. b. brasilianus further south.
in 1789. Many later authors preferred to use the name Phalacrocorax olivaceus based on Alexander von Humboldt
's 1805 description because the identity of Piso's birds was considered uncertain. Recently, many authorities such as the American Ornithologists' Union
have begun to use Phalacrocorax brasilianus after M. Ralph Browning argued that Piso's description and paintings do indeed refer to the Neotropic Cormorant.
. It has a long tail and frequently holds its neck in an S-shape. Adult plumage
is mainly black, with a yellow-brown throat patch. During breeding, white tufts appear on the sides of the head, there are scattered white filoplumes on the side of the head and the neck, and the throat patch develops a white edge. The upper wings are somewhat greyer than the rest of the body. Juveniles are brownish in color.
Its diet consists mainly of small fish
, but will also eat tadpole
s, frog
s, and aquatic insect
s. Information about its prey is sparse, but inland birds seem to feed on small, abundant fish in ponds and sheltered inlets, less than 10 cm in length, with an individual weight of a gram or two, such as Poecilia
spp. especially the sailfin molly
Poecilia latipinna. This cormorant forages for food by diving underwater, propelling itself by its feet. Its dives are brief, between 5 and 15 seconds. It is also known to forage in groups, with several birds beating the water with their wings to drive fish forward into shallows.
Neotropic Cormorants are monogamous and breed in colonies. The nest is a platform of sticks with a depression in the center circled with twigs and grass. It is built a few metres above the ground or water in bushes or trees. Up to five chalky, bluish-white eggs
are laid. Most pairs lay 3 eggs, but the mean number hatched is less than 2. The eggs soon become nest-stained. Both sexes incubate for about 25–30 days, and both parents feed the young until around the 11th week. By week 12, they are independent. One brood is raised per year.
Unlike other cormorants, this bird can often be seen perching on wires.
This bird is largely a permanent resident, with some birds occasionally wandering
north in the warmer months.
Cormorant
The bird family Phalacrocoracidae is represented by some 40 species of cormorants and shags. Several different classifications of the family have been proposed recently, and the number of genera is disputed.- Names :...
found throughout the American tropics and subtropics, from the middle Rio Grande
Rio Grande
The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...
and the Gulf and California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
n coasts of the USA south through Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
to southern South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. It also breeds on the Bahamas, Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
and Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
. It can be found both at coasts (including some mangrove areas) and on inland waters. There are at least two subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
: P. b. mexicanus from Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
northwards and P. b. brasilianus further south.
Taxonomy
The species was documented in 1658 by Willem Piso after travels in Brazil. This formed the basis for the description and naming of the species by Johann Friedrich GmelinJohann Friedrich Gmelin
Johann Friedrich Gmelin was a German naturalist, botanist, entomologist, herpetologist and malacologist.- Education :Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen...
in 1789. Many later authors preferred to use the name Phalacrocorax olivaceus based on Alexander von Humboldt
Alexander von Humboldt
Friedrich Wilhelm Heinrich Alexander Freiherr von Humboldt was a German naturalist and explorer, and the younger brother of the Prussian minister, philosopher and linguist Wilhelm von Humboldt...
's 1805 description because the identity of Piso's birds was considered uncertain. Recently, many authorities such as the American Ornithologists' Union
American Ornithologists' Union
The American Ornithologists' Union is an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders...
have begun to use Phalacrocorax brasilianus after M. Ralph Browning argued that Piso's description and paintings do indeed refer to the Neotropic Cormorant.
Description
This bird is 64 cm long with a 100 cm wingspan. Adults males weigh from 1.1 to 1.5 kg, adult females 50 to 100 grams less. Birds of the southern populations tend to be bigger than the more northerly birds. It is small and slender, especially compared to the larger, heavier-looking Double-crested CormorantDouble-crested Cormorant
The Double-crested Cormorant is a member of the cormorant family of seabirds. It occurs along inland waterways as well as in coastal areas, and is widely distributed across North America, from the Aleutian Islands in Alaska down to Florida and Mexico...
. It has a long tail and frequently holds its neck in an S-shape. Adult plumage
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
is mainly black, with a yellow-brown throat patch. During breeding, white tufts appear on the sides of the head, there are scattered white filoplumes on the side of the head and the neck, and the throat patch develops a white edge. The upper wings are somewhat greyer than the rest of the body. Juveniles are brownish in color.
Behaviour
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, but will also eat tadpole
Tadpole
A tadpole or polliwog is the wholly aquatic larval stage in the life cycle of an amphibian, particularly that of a frog or toad.- Appellation :...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, and aquatic insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. Information about its prey is sparse, but inland birds seem to feed on small, abundant fish in ponds and sheltered inlets, less than 10 cm in length, with an individual weight of a gram or two, such as Poecilia
Poecilia
Poecilia is a genus of euryhaline brackish water fish in family Poeciliidae of order Cyprinodontiformes. The type species is P. vivipara. Live-bearers, the Poecilia species are collectively known as mollies, with the exception of Endler's livebearer and the famous guppy...
spp. especially the sailfin molly
Sailfin molly
The sailfin molly, Poecilia latipinna, is a species of fish, of the genus Poecilia. They inhabit fresh, brackish, and coastal waters from North Carolina to Texas and the Yucatán Peninsula of Mexico.- Taxonomy :...
Poecilia latipinna. This cormorant forages for food by diving underwater, propelling itself by its feet. Its dives are brief, between 5 and 15 seconds. It is also known to forage in groups, with several birds beating the water with their wings to drive fish forward into shallows.
Neotropic Cormorants are monogamous and breed in colonies. The nest is a platform of sticks with a depression in the center circled with twigs and grass. It is built a few metres above the ground or water in bushes or trees. Up to five chalky, bluish-white eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
are laid. Most pairs lay 3 eggs, but the mean number hatched is less than 2. The eggs soon become nest-stained. Both sexes incubate for about 25–30 days, and both parents feed the young until around the 11th week. By week 12, they are independent. One brood is raised per year.
Unlike other cormorants, this bird can often be seen perching on wires.
This bird is largely a permanent resident, with some birds occasionally wandering
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
north in the warmer months.
External links
- Neotropic Cormorant videos, photos & sounds on the Internet Bird Collection