Flightless Cormorant Phalacrocorax harrisi is endemic to Fernandina and Isabela in the Galápagos Islands, Ecuador, and is currently classified as Endangered under criteria B1a+c(iv) and B2a+c(iv) because it has a very small breeding range and a population which has been estimated to have undergone severe fluctuations in the number of mature individuals.
However, according to IUCN guidelines “for the ‘extreme fluctuations’ subcriterion to be invoked, populations would normally need to fluctuate by at least 10-fold (i.e., an order of magnitude difference between population minima and maxima)” – although this species has undoubtedly undergone significant population fluctuations there appears to be no evidence that they meet the IUCN definition of extreme fluctuations. In addition, recent data suggests the population of this species may be stabilising at a new high (Jiménez-Uzcátegui et al. 2006).
It is therefore proposed to reclassify the Flightless Cormorant as Vulnerable under criterion D2, because it has a very restricted area of occupancy and occurs at only two locations such that it is prone to the effects of human activities (such as oil spills) or stochastic events within a very short time period in an uncertain future, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period. Comments on this proposal and any up to date information on population trends and current threats to this species are welcomed.
Jiménez-Uzcátegui, G., Hernán Vargas, F., Larrea, C., Milstead, B. and Llerena, W. (2006) Galapagos Penguin and Flightless Cormorant survey. Report for the Charles Darwin Foundation, The Galapagos National Park and the Seaworld & Busch Gardens Conservation Fund.