||Phalacrocorax harrisi Rothschild, 1898
||Flightless Cormorant, Galapagos Cormorant
Nannopterum harrisi ssp. harrisi (Rothschild, 1898) — Stotz et al. (1996)
Nannopterum harrisi ssp. harrisi (Rothschild, 1898) — Collar and Andrew (1988)
||SACC. 2005 and updates. A classification of the bird species of South America. Available at: #http://www.museum.lsu.edu/~Remsen/SACCBaseline.htm#.
||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.
|Red List Category & Criteria:
||Butchart, S. & Symes, A.
||Cruz, F., Freile, J., Jiménez-Uzcátegui, G., Tye, A., Vargas, H. & Wiedenfeld, D.
||Anderson, O., Benstead, P., Lascelles, B., Moreno, R., Pilgrim, J., Symes, A., Taylor, J., Martin, R
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.
|Previously published Red List assessments:|
- 2016 – Vulnerable (VU)
- 2013 – Vulnerable (VU)
- 2012 – Vulnerable (VU)
- 2011 – Vulnerable (VU)
- 2010 – Endangered (EN)
- 2008 – Endangered (EN)
- 2005 – Endangered (EN)
- 2004 – Endangered (EN)
- 2000 – Endangered (EN)
- 1996 – Vulnerable (VU)
- 1994 – Vulnerable (VU)
- 1988 – Threatened (T)
|Range Description:||Phalacrocorax harrisi is endemic to 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) and few colonies in the north east of Isabela. 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 and Vargas 2007).|
|♦ Estimated area of occupancy (AOO) - km2:||50||♦ Continuing decline in area of occupancy (AOO):||Unknown|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||5900|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Number of Locations:||2||♦ 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:||In 2007, 1,602 individuals were recorded. Therefore, the estimate of population size in 2007, according to the Valle (1994) methodology, was 1,937 individuals (Jiménez-Uzcátegui and Vargas 2007). Since 2010 the census methodology has changed, and in 2013 the population was estimated to be 2,080 individuals (Jiménez-Uzcátegui 2013, Carrera-Játiva et al. 2014).|
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 and Vargas 2007). From 2010 the census methodology changed, and in 2013 the population was estimated in 2,080 individuals (Jiménez-Uzcátegui 2013, Carrera-Játiva et al. 2014).
|Current Population Trend:||Stable|
|♦ Number of mature individuals:||1602||♦ Continuing decline of mature individuals:||Unknown|
|♦ Extreme fluctuations:||No||♦ Population severely fragmented:||No|
|♦ No. of subpopulations:||1||♦ Continuing decline in subpopulations:||Unknown|
|♦ Extreme fluctuations in subpopulations:||No||♦ All individuals in one subpopulation:||Yes|
|♦ No. of individuals in largest subpopulation:||100|
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 and Vargas 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 (Vargas 2006, Wiedenfeld and Jiménez-Uzcátegui 2008, 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 on Fernandina (they are present on Isabela) (Valle 1986, H. Vargas and F. Cruz in litt. 2000, D. Wiedenfeld in litt. 2011). The introduction of parasites and pathogens is also a potential threat (J. Freile in litt. 2010, Carrera-Játiva et al. 2014). 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 (Wiedenfeld and Jiménez-Uzcátegui 2008, Deem et al. 2010). Illegal fishing activities are increasing around Fernandina and Isabela (H. Vargas and F. Cruz in litt. 2000, Wiedenfeld and Jiménez-Uzcátegui 2008).