The guanay cormorant or guanay shag (''Leucocarbo bougainvilliorum'') is a member of the cormorant

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

found on the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

coast of

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and northern

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. After breeding it spreads south to southern parts of Chile and north to

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

, and has also been recorded as far north as

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

and

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

, probably a result of mass dispersal due to food shortage in

El Niño EL, El or el may refer to: Arts and entertainment Fictional entities * El, a character from the manga series ''Shugo Chara!'' by Peach-Pit * Eleven (''Stranger Things'') (El), a fictional character in the TV series ''Stranger Things'' * El, fami ...

years. Its major

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s include shallow seawater and rocky shores. A former population on the Patagonian

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

coast of

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

appears to be

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

Taxonomy

Most taxonomic authorities, including the

International Ornithologists' Union The International Ornithologists' Union (IOU) is an international organization for the promotion of ornithology Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", ...

, place this species in the genus ''

Leucocarbo ''Leucocarbo'' is a genus of birds in the family Phalacrocoracidae. Several species within the genus are collectively known as blue-eyed shags. This is a group of closely related cormorant taxa. Many have a blue, purple or red ring around the ey ...

''. In the past, it was usually placed in a broad circumscription of the genus ''

Phalacrocorax ''Phalacrocorax'' is a genus of fish-eating birds in the cormorant family Phalacrocoracidae. Members of this genus are also known as the Old World cormorants. Taxonomy The genus ''Phalacrocorax'' was introduced by the French zoologist Mathurin ...

'', and some authors still follow this. The scientific name commemorates the French naval officers

Louis Antoine de Bougainville Louis-Antoine, Comte de Bougainville (; 12 November 1729 – 31 August 1811) was a French military officer and explorer. A contemporary of the British explorer James Cook, he served in the Seven Years' War and the American Revolutionary War. B ...

and his son

Hyacinthe de Bougainville Hyacinthe Yves Philippe Potentien, baron de Bougainville (; 26 December 1781 – 18 October 1846) was a French naval officer. He was the son of Louis-Antoine de Bougainville.Randier, p.292 He became Rear-Admiral on 1 May 1838. Career As a y ...

; the species epithet was corrected from the original ''bougainvillii'' to the plural spelling ''bougainvilliorum'' ("of the Bougainvilles") in 2020 to reflect this dual honoring.

Description

The guanay cormorant is similar in plumage to the rock shag ''Leucocarbo magellanicus'', but is larger, measuring 71–78 cm from the tip of the

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Pl ...

to the end of the tail, and has more extensive white on the underparts. The bill is grayish with some red at the base. The face is red with a green

eye-ring The eye-ring of a bird is a ring of tiny feathers that surrounds the orbital ring, a ring of bare skin immediately surrounding a bird's eye. The eye-ring is often decorative, and its colour may contrast with adjoining plumage. The ring of feather ...

. It has orange-pink feet. The head, neck and back are black, as are the outer parts of the thighs. The throat patch, breast and belly are white. In breeding plumage it has a few white feathers on the sides of the head and neck.

Ecology

Breeding occurs year round with a peak in November and December. The

nest A nest is a structure built for certain animals to hold Egg (biology), eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of ...

is built of

guano Guano (Spanish from ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a le ...

on flat surfaces on offshore islands or remote headlands. There are up to three nests per square meter in high-density

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

. The guanay cormorant lays two or three

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

of approximately 63 × 40 mm in size. It feeds mainly on the

Peruvian anchoveta The Peruvian anchoveta (''Engraulis ringens'') is a species of fish of the anchovy family, Engraulidae, from the Southeast Pacific Ocean. It is one of the most commercially important fish species in the world, with annual harvests varying betw ...

''Engraulis ringens'', and the Peruvian silverside ''Odontesthes regia'', which thrive in the cold

Humboldt Current The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America.Montecino, Vivian, and Carina B. Lange. "The Humboldt Current System: Ecosystem components and pro ...

. The guanay cormorant is the main producer of

Habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and degradation and over-fishing have resulted in a steady decline of the population of about 30% from an estimated figure of three million birds in 1984. This species is listed as

near threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. The bird's droppings were such an important source of fertilizer to the peoples of the Andes that it was protected by Inca rulers, who supposedly made disturbing the cormorants in any way punishable by death. The common name is an adaptation of the South American Spanish ''guanae'', a plural of the English equivalent ''guano''.

References

* * * *

External links

* {{Taxonbar, from=Q27074617 Guanay cormorant Guanay cormorant Birds of Chile Birds of Peru Birds of Ecuador Birds of Patagonia Taxa named by René Lesson Western South American coastal birds