10,000 to >1,000,000 individuals
Comments: Rangewide estimates not available. Subspecies CALIDUS: breeding poulation across northern Eurasia has been estimated at 3652 territorial pairs (95% confidence interval 2282 to 5018 pairs) (Quinn and Kokorev 2000). North America: In the early 1990s, the North American population totaled several thousand breeding pairs, including about 700 known territorial pairs in the coterminous U.S. (estimated total about 890 pairs). Subspecies PEALEI: An estimated 600 breeding pairs are believed to occur in Alaska (Ambrose et al. 1988) and an additional 100 pairs in British Columbia (Munro 1988). Subspecies ANATUM: In 1998, there were at least 193 breeding pairs in the eastern United States, 32 in the midwest, 535 in the western region, and 269 in the Pacific coast region (USFWS 1999). In Alaska, there are a minimum of 301 breeding pairs (USFWS 1999). In Canada, 319 breeding pairs were located in 1995 (USFWS 1999). Mexico has not been surveyed adequately, but at least 70 nest sites were occupied there in the late 1980s and early 1990s (USFWS 1999). Subspecies TUNDRIUS: In Greenland, there were approximately 1000-2000 breeding pairs in the early 1990s (Mattox, in USFWS 1993). Alaskan nesting population was estimated at 200-250 pairs in the early 1990s. Additional pairs in the Northwest Territories and elsewhere bring the total up to probably several thousand breeding pairs.