Justification of Red List Category
This species has an extremely 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). The population trend appears to be increasing, and hence the species does not 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.930,000-1,600,000 individuals (Wetlands International 2006), while national population sizes have been estimated at c.50-10,000 wintering individuals in Japan and c.100-10,000 breeding pairs c.1,000-10,000 wintering individuals in Russia (Brazil 2009).
This species has undergone a large and statistically significant increase over the last 40 years in North America (148% increase over 40 years, equating to a 25.5% increase per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).
The Pacific Loon can be found in the tundra regions of Alaska (U.S.A.) and northern Canada, and the far east of Russia. During winter, its range expands to include the Pacific coast of Asia down to eastern China, as well as North America down to Baja California (Mexico) (del Hoyo et al. 1992).
This species breeds on fairly large, deep freshwater lakes and winters on inshore waters along sheltered coasts, and occasionally inland. It feeds mostly on fish, but also on aquatic insects, molluscs, crustaceans and some plant matter. Fish are caught under water by pursuit-diving. Breeding begins in March in the south of the range, and depends on the timing of spring in the north. Nesting is solitary on heaps of plant matter near the water's edge (del Hoyo et al. 1992).
This species is at some risk from oil spills, however, they are not thought to cause significant declines in the global population.
Text account compilers
Calvert, R., Ekstrom, J., Bennett, S., Butchart, S., Fjagesund, T., Hermes, C., Stuart, A.
BirdLife International (2019) Species factsheet: Gavia pacifica. Downloaded from http://www.birdlife.org on 19/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/09/2019.