| Most recent survey year | Individuals | Years | Trend | Comments, and ratio used for separating Common from Thick-billed murres | |
| Northern Bering Sea/eastern Chukchi Sea | |||||
| Cape Thompson | 1960 | 190,000 | 8 | Stable | 49% COMU, 51% TBMU (ratio for whole ARC region, based on known COMU/TBMU counts) |
| Cape Lisburne | 1977 (adjusted with plot data through 2013) | 160,000 | 20 | Increasing | 35% COMU, 65% TBMU (BSCC) |
| St. Lawrence Island | 1977-1997 (adjusted with plot data through 2004) | 160,000 | 5 | 61% COMU, 39% TBMU (BSCC) | |
| Bluff | 1985 (adjusted with plot data through 2007) | 50,000 | 25 | 56,000 COMU:560 TBMU (BSCC) | |
| King Island | 1976 | 50,000 | |||
| Little Diomede | 1991 | 15,000 | 49% COMU, 51% TBMU (ratio for whole ARC region, based on known COMU/TBMU counts) | ||
| Cape Denbigh | 1976 | 10,000 | |||
| Other (14 sites) | 1972-1981 | 25,000 | |||
| Subtotal | >21 sites | 660,000 | |||
| Eastern Bering Sea | |||||
| St. George Island | 1989 (updated with plot data through 2014) | 270,000 | 14 | Stable | 16% COMU, 84% TBMU (BSCC) |
| Round Island | 1994 (updated with plot data through 2014) | 130,000 | 16 | Decreasing | |
| Nunivak Island | 1978 (updated with plot data through 1998) | 120,000 | 4 | 40% COMU, 60% TBMU (ratio for whole EBS region, based on known COMU/TBMU counts) | |
| Bird Rock | 1994 | 100,000 | |||
| Shaiak Island | 1994 | 100,000 | |||
| North Twin | 1994 | 100,000 | |||
| St. Matthew Island | 1977 | 70,000 | 31% COMU, 69% TBMU (BSCC) | ||
| Hall Island | 1977 (updated with plot data through 2012) | 60,000 | 6 | 31% COMU, 69% TBMU (BSCC) | |
| Jagged Mountain | 1994 | 40,000 | |||
| Pinnacle Island | 1985 | 30,000 | 31% COMU, 69% TBMU (BSCC) | ||
| Hagemeister Island | 1977-1994 | 25,000 | |||
| Cape Newenham | 1973 (updated with plot data through 1997) | 25,000 | 5 | ||
| Black Rock | 1994 | 25,000 | |||
| High Island | 1994 | 20,000 | |||
| South Twin | 1994 | 20,000 | |||
| Other (21 sites) | 1973-2005 | 80,000 | Cape Pierce, stable; St Paul Island, slight decrease | ||
| Subtotal | >36 islands and headlands | 1,215,000 | |||
| Aleutian Islands | |||||
| Kagamil Island | 1982 | 7,000 | |||
| Agattu Island | 2003 | 6,000 | 19 | Unidentified murres were assigned 80% COMU, 20% TBMU (BSCC and old AMNWR report ratios). | |
| Semisopochnoi Is | 2004 | 3,000 | |||
| Koniuji Island | 2010 | 1,500 | 9 | Unidentified murres were assigned 25% COMU, 75% TBMU (BSCC) | |
| Seguam Island | 1982 | 1,300 | |||
| Buldir Island | 1992 (adjusted with plot data through 2013) | 1,200 | 18 | Increasing | Entire island count projected based on trends on index plots. Unidentified murres were assigned 1% COMU, 99% TBMU (AMNWR pop plot data). |
| Other (25 sites) | 1976-2014 | 3200 | Unidentified murres were primarily assigned based on generalized ratios in region or based on colony ratio information where available. | ||
| Subtotal | 31 small islands/islets | 23,200 | |||
| Gulf of Alaska | |||||
| Aghiyuk Island | 1979 | 430,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| Chowiet Island | 1979 (updated with plot data through 2014) | 400,000 | 23 | Increasing | 97% COMU, 3% TBMU (ratio in AMNWR plot counts) |
| Aliksemit Island | 1979 | 140,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| Kateekuk Island | 1979 | 100,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| South Island | 1979 | 80,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| Suklik Island | 1979 | 60,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| Anowik Island | 1979 | 40,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| Aghik Island | 1979 | 40,000 | 97% COMU, 3% TBMU (ratio of plot counts on Chowiet for all Semidis) | ||
| East Amatuli Island | 1997 (updated with plot data through 2018) | 30,000 | 7 | ||
| Other AK (73 sites) | 1973-2014 | 200,000 | Puale Bay, St Lazaria, stable; Gull, Chisik/Duck, decreasing | ||
| Queen Charlotte Is | 2007 | 6,000 | 37; 2 locations | ||
| Subtotal | 84 islands/islets and headlands | 1,526,000 | |||
| TOTAL | >172 breeding sites | 3,424,200 | Breeding birds | ||
| 2,396,940 | Pairs b | ||||
a Compiled by H. Renner and colleagues at US Fish & Wildlife Service
b Breeding pairs derived from direct counts of adults, or by counts of individual birds present by applying correction factor of 0.7 (see 497, 364, 365).