Phalacrocorax bougainvilliorum 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Suliformes Phalacrocoracidae

Scientific Name: Phalacrocorax bougainvilliorum (Lesson, 1837)
Common Name(s):
English Guanay Cormorant
Spanish Cormorán Guanay
Phalacrocorax bougainvillii
Taxonomic Source(s): SACC. 2005 and updates. A classification of the bird species of South America. Available at: #
Taxonomic Notes: Phalacrocorax bougainvilliorum (del Hoyo and Collar 2014) was previously listed as P. bougainvillii.
Identification information: 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.

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2016
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Barbraud, C., Engblom, G., Frere, E., Majluf, P. & Roca, M.
Facilitator/Compiler(s): Benstead, P., Calvert, R., Lascelles, B., Moreno, R., Sharpe, C.J., Symes, A.
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.

Previously published Red List assessments:

Geographic Range [top]

Range Description:

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, 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).
Countries occurrence:
Chile; Ecuador; Peru
Possibly extinct:
Colombia; Panama
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:2820000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:No
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Zavalaga and 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).

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Unknown
Extreme fluctuations:NoPopulation severely fragmented:No
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Breeding occurs year round with most egg-laying in May-December (on the northern coast of Perú, breeding starts in May-September, on the southern coast of Perú, breeding starts October-December, Passuni et al. 2016). It breeds on offshore islands and remote coastal headlands and feeds exclusively in the inshore environment usually within 19 km of colonies (Zavalaga and Paredes 1999, Weimerskirch et al. 2012). 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).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Unknown
Generation Length (years):11
Movement patterns:Not a Migrant
Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): 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. Competition with the industrial fishery represents the biggest current threat (Duffy 2000). Consumption of birds still represents a threat with around 20,000 birds taken each year in Northern Peru (P. Majluf in litt. 2007). Declines have been particularly evident since the final collapse of the anchoveta stocks in 1974 (del Hoyo et al. 1992), and the start of the industrial fishery (Duffy 2000). 

Conservation Actions [top]

Conservation Actions:

Conservation Actions Underway

Several breeding colonies lie within managed guano reserves or in Marine Protected Areas. 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 impact of anchovy fishery on foraging behaviour, breeding seasonality and population dynamics. Evaluate the human consumption of the species in Peru and Chile. Protect important colonies and regulate, or if necessary halt, exploitation. 

Citation: BirdLife International. 2016. Phalacrocorax bougainvilliorum. The IUCN Red List of Threatened Species 2016: e.T22696810A93588407. . Downloaded on 18 June 2018.
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