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Guanay Cormorant Phalacrocorax bougainvilliorum
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This species is suspected to have experienced moderately rapid declines in the past three generations (33 years) and as a result it is classified as Near Threatened.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
SACC. 2006. A classification of the bird species of South America. Available at: #

Taxonomic note
Phalacrocorax bougainvilliorum (del Hoyo and Collar 2014) was previously listed as P. bougainvillii.

Phalacrocorax bougainvillii

76 cm . Upperparts black, with blueish tinge to neck and head, white neck, chest, belly and undertail. Deep red skin around eyes and base of the bill is pink. Feet are also pink (Koepcke 1964). Similar Species: Within its range could be confused with Red-legged Cormorant, but latter is grey not black and has distinctive white neck patch.

Distribution and population
Phalacrocorax bougainvilliorum is found along the Pacific coast of Peru and northern Chile. A small population also bred on a short stretch of the Patagonian Atlantic coast of Argentina, but this appears to be ecologically extinct (Bertellotti et al. 2003). From historical times the Guanay Cormorant has been the dominant avian species in the Peruvian Coastal Current in terms of numbers and consumption of marine resources. The population in Peru was estimated as <4 million birds during the period 1909-1920; 21 million were estimated in 1954 and 3.7 million were estimated on the north-central Peruvian coast in 1996 (Zavalaga and Paredes 1999). Mass dispersal, breeding failures and temporary declines have resulted periodically from El Niño Southern Oscillation (ENSO) events, and both fish-stocks and the populations of seabirds that depend on them are adapted to these fluctuations. Although the species is now protected in Peru, fishing for anchoveta is banned, and the guano industry is adequately regulated, there are concerns that this species has been badly affected by the ENSO event of 1998 (G. Engblom in litt. 2003), and that declines now approach 30% over three generations (33 years in this species).

Population justification
Zavalaga & Paredes (1999) estimated the population at 3.7 million individuals, hence the population is best placed in the band 2,500,000-4,999,999 individuals.

Trend justification
The species has fluctuated in numbers in the past, but overall declines in the region of 20-30% are suspected in the past three generations (33 years).

Breeding occurs year round with an egg-laying peak in November-December (on the northern coast of Perú, breeding starts in June). It breeds on offshore islands and remote coastal headlands and feeds exclusively in the inshore environment usually within 3 km of colonies (Zavalaga and Paredes 1999). Unlike other cormorants it is not primarily a benthic feeder but preys mainly on the schooling Peruvian anchovy Engraulis ringens, Peruvian silverside Odonthestes regia and mote sculpin Normanichythes crockeri found in the cold water of the Humboldt Current (del Hoyo et al. 1992, Zavalaga and Paredes 1999).

Historical declines were due to guano exploitation and overfishing of key food sources (del Hoyo et al. 1992). These threats are now managed to some degree. Consumption of birds perhaps represents the biggest current threat with around 20,000 birds taken each year in Northern Peru (P. Majluf in litt. 2007). Another potential cause of population declines in Peru is high predation rates on eggs and small chicks by Band-tailed Gull Larus belcheri. Declines have been particularly evident since the final collapse of the anchoveta stocks in 1974 (del Hoyo et al. 1992).

Conservation Actions Underway
Several breeding colonies lie within managed guano reserves or in Marine Protected Areas. Closure of the Anchovy fishery has reduced impact of declining food sources. Education and awareness on the importance of the conservation of this species has helped raise its local profile. Conservation Actions Proposed
Development of a standardised methodology to estimate the population size throughout the breeding range. Evaluate the human consumption of the species in Peru and Chile. Protect important colonies and regulate, or if neccesary halt, exploitation.

Related state of the world's birds case studies

Bertellotti, M.; Donázar, J. A.; Blanco, G.; Forero, M. G. 2003. Imminent extinction of the Guanay Cormorant on the Atlantic South American coast: a conservation concern? Biodiversity and Conservation 12: 743-747.

Croxall, J. P.; Prince, P. A.; Hunter, I.; McInnes, S. J.; Copestake, P. G. 1984. Seabirds of the Antarctic Peninsula, islands of the Scotia Sea, and Antarctic continent between 80ºW and 20ºW: their status and conservation. In: Croxall, J.P.; Evans, P.G.H.; Schreiber, R.W. (ed.), Status and conservation of the world's seabirds, pp. 637-666. International Council for Bird Preservation, Cambridge, U.K.

del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: (Accessed: 19 June 2012).

Koepcke, M. 1964. Gráfica Morsom SA, Lima, Peru.

Zavalaga, C. B.; Paredes, R. 1999. Foraging behaviour and diet of the Guanay Cormorant. South African Journal of Marine Science 21: 251-258.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Calvert, R., Lascelles, B., Sharpe, C J & Symes, A.

Engblom, G., Frere, E., Majluf, P. & Roca, M.

Recommended citation
BirdLife International (2016) Species factsheet: Phalacrocorax bougainvilliorum. Downloaded from on 21/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 21/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Near Threatened
Family Phalacrocoracidae (Cormorants)
Species name author (Lesson, 1837)
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 466,000 km2
Country endemic? No
Links to further information
- Additional Information on this species