COSEWIC Assessment and Update Status Report on the Ancient Murrelet in Canada
- Assessment Summary
- Executive Summary
- COSEWIC History, Mandate, Membership and Definitions
- Lists of Figures and Tables
- Species Information
- Population Sizes and Trends
- Limiting Factors and Threats
- Special Significance of the Species
- Existing Protection or Other Status
- Technical Summary
- Acknowledgements and Information Sources
- Biographical Summary of Report Writer and Authorities Contacted
Ancient Murrelets breed in a thin arc about 9000 km in length around the northern rim of the Pacific Ocean (Fig. 1). The species becomes progressively more abundant from China to British Columbia. Udvardy (1963) defined their distribution as “subboreal, pan-Pacific”, similar to the Rhinoceros Auklet, Cerorhinca monocerata, and the Tufted Puffin, Fratercula cirrhata, which breed south to California in the eastern Pacific. In winter, the species spreads south as far as California and Taiwan (Gaston 1992).
In Asia, information about distribution and numbers of Ancient Murrelets is limited by the absence of survey work. Based on previous data collected, populations in China, Korea and Japan may be in danger of extirpation (Springer et al. 1993; Gaston 1994). There are probably no more than a few hundred pairs of Ancient Murrelets breeding in China, a few thousand on the Korean Peninsula, and a similar number around the coasts of the Sea of Japan. Approximately, 25 000 - 35 000 individuals breed in the Northern Sea of Okhotsk (Kondratyev et al. 2000), 13 000 individuals in Kamchatka (Kondratyev et al. 2000) and less than 2 000 in the Commander Islands (Kondratyev et al. 2000).
Ancient Murrelets also breed on several islands in Peter the Great Bay off Vladivostok, in discrete nesting areas. Shibaev (1987) estimated 500 pairs on Verkhovskii Island and in the same area, the species has been recorded breeding on Russkii, Karamzin (100 pairs in the 1960s) and Klykov islands, with an estimated the total population of 1200 pairs (Litvinenko and Shibaev 1991).
The largest estimated Ancient Murrelet colony in the Asian part of the North Pacific is on Talan Island in Tauyskaya Bay where there are approximately 22 000 individuals (USFWS 2003). There is also an estimated population of 13 000 birds on Starichkov Island (USFWS 2003).
In Alaska, the species is common in the Aleutian Islands, Gulf of Alaska and the Alaskan Peninsula, though population estimates are incomplete. The population of this entire region is estimated at around 200 000 (USFWS 2003). The largest colony is at Forrester Island, SE Alaska, with approximately 60 000 individuals present in 1976. Other large colonies include Castle Rock in the Shumagins with 30 000 individuals in 1976. Several other islands in this vicinity are estimated to have over approximately 500 individuals. Hunt Island (1978), Koniuji Island (1982) and Buldir Island (1976) all have approximately 10 000 individuals (USFWS 2003). Chagaluk and Egg Island each had approximately 5000 individuals in 1982 and 1980, respectively. The only other colony of any size is on St. Lazaria Island (1,500 birds in 1981) (USFWS 2003). During the winter, Ancient Murrelets disperse as far as California, arriving in late October (Ainley 1976).
Outside the Queen Charlotte Islands, there are only two definite records of Ancient Murrelets breeding in North America south of Alaska. Hoffman (1924) found a nest with eggs on Carroll Island, Washington, and a nest was reported in 1970 on an island in the Moore Group off the mainland coast of Hecate Strait, BC (Campbell et al. 1990). There have been no subsequent records from Washington, but small numbers are seen offshore and a fledgling was recorded in 1978. A very small breeding population may still exist there (Speich and Wahl 1989).
An estimated 256,000 pairs of Ancient Murrelets, about half the world breeding population, occur on 31 islands in the Queen Charlotte Islands (Rodway 1991; Gaston 1992; Vermeer et al. 1997, Fig. 2). Canada remains the only part of the species breeding range where population estimates are accurate to within orders of magnitude (Gaston 1994b). They are concentrated in two areas: off the west coast of Graham Island in the north, and off the east coast of Moresby Island in the south. The four colonies off Graham Island support approximately 49% of the breeding population, while the 17 colonies along the east coast of Moresby Island, mostly within Gwaii Haanas National Park Reserve, support about 44% of the breeding population (Lemon and Gaston 1999). There are also 10 colonies on the remote and rugged west coast of Moresby Island, which account for the remaining 7% (Rodway 1991).
The colonies off Graham Island have been known since the early 1900s, but no attempt was made to census them until 1981, although Spencer Sealy made a retrospective estimate of the size of the Langara Island colony for 1970-1971. Before that, only general statements such as “astronomical” (Beebe 1960), “immense numbers” or “thousands” (Drent and Guiguet 1961) were available. We have an even shorter record of the South Moresby colonies, which were unknown to outsiders until the 1960s, although familiar to the local Haida. For most Ancient Murrelet colonies in the archipelago, even orders of magnitude were uncertain until the 1980s.
From Harfenist et al. 2002; data from Rodway 1988; Rodway et al. 1988, 1990; Harfenist 1994; Lemon 1997; Gaston and Masselink 1997; Gray 1999; Lemon and Gaston 1999.
Small numbers are also seen off the northern part of the west coast of Vancouver Island in summer and breeding may occur but remains unconfirmed. Family groups, including small chicks, are also sometimes seen in the southern part of the Queen Charlotte Islands (Smith and French 2000), because dispersal away from the breeding sites is very rapid (Duncan and Gaston 1990).
On Boulder and Sea-Pigeon Islands, in the inner part of the Skincuttle Inlet, Bristol Foster reported eggshells and the remains of dead adults in 1960 (Drent and Guiguet 1961), but by 1971 there was no sign of breeding (Summers 1974). Introduced raccoons are sometimes present on Boulder and Sea-Pigeon Islands (Rodway et al. 1988) and may have been responsible for the disappearance of Ancient Murrelets.
In 1971, Summers (1974) found abundant burrowing on Arichika Island and the Bischof Islands, and estimated 500 pairs were present at each location. This estimate was based on a combination of field records of abundance of burrows and proportions of islands covered by burrows, and sometimes by the amount of nocturnal activity. In 1985, Rodway et al. (1988) found no trace of these colonies.
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