Justification of Red List Category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population is estimated to number > c.200,000 individuals (Delany and Scott 2006), while national population sizes have been estimated at < c.100 breeding pairs and < c.50 wintering individuals in Japan and c.100-10,000 breeding pairs in Russia (Brazil 2009).
The population trend is decreasing in North America (based on BBS/CBC data: Butcher and Niven 2007).
The Red-faced Cormorant can be found in the north Pacific from Hokkaido (Japan), the Kuril Islands and Commander Islands (Russia) eastwards to the Aleutian Islands and southern Alaska (USA) (del Hoyo et al. 1992).
This exclusively marine species feeds on a variety of small fish and crustaceans, including crabs and shrimps, which is catches mainly by pursuit diving. It lays in May or June, forming colonies along rocky coasts and on offshore islands. Nests are normally built on cliff ledges. It is mainly sedentary, dispersing over nearby coasts during winter (del Hoyo et al. 1992).
A study from the Pribilof Islands colony showed that the primary causes of egg loss in 2004-05 were predation by Arctic foxes Vulpes lagopus and destruction of eggs and abandonment of nests due to severe weather events. Approximately 12% of eggs did not hatch in 2004, and 22% did not hatch in 2005, the difference likely explained by the two storms in May and June 2005. Low-lying nests suffer destruction by wave action and higher nests may also be soaked, causing nest abandonment and/or hatching failure. Climate change models predict increasing poleward movement of extratropical storm tracks (IPCC 2007 in Wright et al. 2013), potentially leading to more extreme and more frequent storms in northern regions (Wright et al. 2013).
Text account compilers
Calvert, R., Butchart, S., Fjagesund, T., Martin, R., Miller, E., Ekstrom, J.
BirdLife International (2019) Species factsheet: Urile urile. Downloaded from http://www.birdlife.org on 06/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/12/2019.