The Flightless Cormorant Phalacrocorax harrisi is endemic to

morphologically and behaviorally unique among extant species of cormorants (Phalacrocoracidae) because of its flightlessness and sequential polyandrous mating system (Valle 1994, Kennedy et al. 2009, Valle 2009). The IUCN listed the Flightless Cormorant as endangered (EN) until 2010, but changed its listing in 2011 to vulnerable (VU) “because evidence suggests that the population is stabilizing and the recorded fluctuations during the last three decades have not been extreme ” (IUCN 2011). However, its small population size, with numbers fluctuating between 700 and 1 900 individuals during the last three decades (Jiménez-Uzcátegui 2010) as well as its restricted distribution range around Fernandina and the Isabela islands (except the southern and southeastern parts) make the species vulnerable to the impact of recurrent El Niño events (Valle & Coulter 1987, Valle 1995), increases in pathogens (Travi