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Flightless Cormorant Phalacrocorax harrisi
BirdLife is updating this factsheet for the 2016 Red List
Please email us with any relevant information

This species qualifies as Vulnerable because it occupies an extremely small range, comprising only two locations, and its status could change in a short space of time, such that it qualifies as Critically Endangered, or even Extinct, owing to potential future threats.

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: #

Nannopterum harrisi Collar and Andrew (1988), Nannopterum harrisi Stotz et al. (1996)

89-100 cm. Unmistakable, very large, dark, flightless cormorant. Adults similar though male significantly larger. Tiny, tatty-looking wings. Almost black upperparts, brownish underparts, turquoise eye. Long, hooked beak. Juvenile glossy black with dull-coloured eye. Voice Adult makes low growl.

Distribution and population
Phalacrocorax harrisi is endemic to Fernandina and Isabela in the Galápagos Islands, Ecuador. It is found around most of the coast of Fernandina (mainly on the east), but only on the north and west coasts of Isabela (Valle and Coulter 1987, H. Vargas and F. Cruz in litt. 2000). In 1971-1972, the population was estimated at 800 pairs (Harris 1973). Between 1977 and 1985, it remained more or less stable at around 650 to 850 adults (Harris 1973, Valle 1986, Valle and Coulter 1987). However, during the 1983 El Niño event, the population declined by 50% to 400 birds, but recovered within a season (Valle and Coulter 1987). In 1986, it was estimated at 1,000 adults (Rosenberg et al. 1990). In 1999, a total of 900 individuals was counted during the census (H. Vargas and F. Cruz in litt. 2000). A total of 1,396 cormorants were counted in 2006, which is 10% less than the population counted in 2005. Nevertheless, the total counted in 2006 is one of the four highest counts among all cormorant surveys conducted since 1977. After the last El Niño event of 1997-1998, growth in the cormorant population has been higher than ever before in the survey period (1977-2006). Still, results as of 2003 show a decrease in the rate of population growth and a low percentage of juveniles (3% in 2006), suggesting that the population is stabilizing at a new high (Jiménez-Uzcátegui et al. 2007).

Population justification
In 2006, 1,338 adults were recorded. Therefore, the estimate of population size in 2006, according to the Valle (1994) methodology, was 1,679 individuals.

Trend justification
This species has undergone marked fluctuations since 1977, with the population estimate ranging from 400 individuals due to the 1983 El Niño (Valle and Coulter 1987) to 1,396 individuals in 2006 (Jiménez-Uzcátegui et al. 2007).

It usually nests in sheltered areas, on shingle and flat lava outcrops (Levéque 1963), mostly within 100 m of the shoreline (Harris 1974). It is thought to breed near the coldest and richest waters (Harris 1974, Valle 1986). It nests in small groups of just a few pairs (Levéque 1963), mainly during the colder season (July-October) when marine productivity is highest, and the risk of heat stress to chicks and incubating adults is reduced (Harris 1974). Some pairs may nest biannually (Valle and Coulter 1987). It is highly sedentary (Valle 1986) and fearless of humans (Levéque 1963). It preys on eels, octopuses and fish (Jiménez-Uzcátegui et al. 2007).

Its flightlessness and disinclination to disperse render it extremely susceptible to human disturbance (Levéque 1963) and catastrophes such as oil spills (Valle 1986). Moreover, they may be affected by nest flooding or even volcanic eruptions (Jiménez-Uzcátegui et al. 2007, D. Wiedenfeld in litt. 2011). Although the species has shown itself to be capable of recovery, further environmental changes and fluctuations will continue to be a threat, and may be increasing in intensity; the effects of climate change and more frequent and severe El Niño Southern Oscillation events could have potentially catastrophic impacts on the species in the future (J. Freile in litt. 2010, G. Jiménez-Uzcátegui in litt. 2011, D. Wiedenfeld in litt. 2011). Introductions of rats, cats and dogs could have a significant impact on the species (Valle 1986, D. Wiedenfeld in litt. 2011) on Fernandina (they are present on Isabela) (H. Vargas and F. Cruz in litt. 2000). The introduction of parasites and pathogens is also a potential threat (J. Freile in litt. 2010). Samples collected from birds on Islabela and Fernandina in 2003-2005 and 2008 tested positive for Toxoplasma gondii antibodies - a common protozoan parasite of humans and warm-blooded animals, thought to originate from feral cats, pointing to additional risks from this invasive predator beyond direct predation (Deem et al. 2010). Illegal fishing activities are increasing around Fernandina and Isabela (H. Vargas and F. Cruz in litt. 2000).

Conservation Actions Underway
All populations are within the Galápagos National Park and Marine Reserve (A. Tye in litt. 2000, H. Vargas and F. Cruz in litt. 2000). In 1979, the islands were declared a World Heritage Site (Jackson 1985). A research project investigating the factors behind the species's decline commenced in August 2003 (H. Vargas in litt. 2003). Invasive species are controlled (Jiménez-Uzcátegui et al. 2007). Conservation Actions Proposed
Monitor both island populations annually (Rosenberg et al. 1990). Minimise human disturbance. Stop net-fishing within feeding range. Continue the cat control program (Jiménez-Uzcátegui et al. 2007). Reduce or ban fishing activities and hunting (hogs and other animals) with household dogs in Iguana Cove and other places in Zone 8 where the largest growth in penguin and cormorant populations has been detected in the last few years (Jiménez-Uzcátegui et al. 2007).  Consider establishing a captive breeding programme.

Collar, N. J.; Butchart, S. H. M. 2013. Conservation breeding and avian diversity: chances and challenges. International Zoo Yearbook.

Collar, N. J.; Gonzaga, L. P.; Krabbe, N.; Madroño Nieto, A.; Naranjo, L. G.; Parker, T. A.; Wege, D. C. 1992. Threatened birds of the Americas: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, Cambridge, U.K.

Deem, S. L.; Merkel, J.; Ballweber, L.; Vargas, F. H.; Cruz, M. B.; Parker, P. G. 2010. Exposure to Toxoplasma gondii in Galapagos Penguins (Spheniscus mendiculus) and Flightless Cormorants (Phalacrocorax harrisi) in the Galapagos Islands, Ecuador. Journal of Wildlife Diseases 46(3): 1005-1011.

Harris, M. P. 1973. The Galápagos avifauna. Condor 75: 265-278.

Harris, M. P. 1974. A complete census of the Flightless Cormorant (Nannopterum harrisi). Biological Conservation 6: 188-191.

Jackson, M. H. 1985. Galapagos: a natural history guide. Calgary University Press, Calgary, Canada.

Jiménez-Uzcátegui, G.; Hernán Vargas, F.; Larrea, C.; Milstead, B.; Llerena, W. 2006. Galapagos Penguin and Flightless Cormorant survey.

Jiménez-Uzcátegui, G. 2007. Censo del Cucuve de Floreana: Nesomimus trifasciatus 2007.

Levéque, R. 1963. The status of some rarer Galápagos birds. Bulletin of the International Council for Bird Preservation IX: 96-99.

Rosenberg, D. K.; Valle, C. A.; Coulter, M. C.; Harcourt, S. A. 1990. Monitoring Galápagos Penguins and Flightless Cormorants in the Galápagos Islands. Wilson Bulletin 102: 525-532.

Valle, C. 1986. Status of the Galápagos Penguin and Flightless Cormorant. Notícias de Galápagos 43: 16-17.

Valle, C. A. 1995. Effective population size and demography of the rare flightless Galapagos cormorant. Ecological Applications 5: 601-617.

Valle, C. A.; Coulter, M. C. 1987. Present status of the Flightless Cormorant, Galápagos Penguin and Greater Flamingo populations in the Galápagos Islands, Ecuador, after the 1982-1983 El Niño. Condor 89: 276-281.

Further web sources of information
Alliance for Zero Extinction (AZE) species/site profile. This species has been identified as an AZE trigger due to its IUCN Red List status and limited range.

Click here for more information about the Alliance for Zero Extinction (AZE)

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
Anderson, O., Benstead, P., Lascelles, B., Pilgrim, J., Symes, A., Taylor, J.

Cruz, F., Freile, J., Jiménez-Uzcátegui, G., Tye, A., Vargas, H., Wiedenfeld, D.

Recommended citation
BirdLife International (2016) Species factsheet: Phalacrocorax harrisi. Downloaded from on 25/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 25/10/2016.

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.

Additional resources for this species

ARKive species - Flightless cormorant (Phalacrocorax harrisi) 0

Key facts
Current IUCN Red List category Vulnerable
Family Phalacrocoracidae (Cormorants)
Species name author (Rothschild, 1898)
Population size 1338 mature individuals
Population trend Stable
Distribution size (breeding/resident) 46 km2
Country endemic? Yes
Links to further information
- Additional Information on this species