Short-tailed Albatross (Phoebastria Albatrus)
- 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
- Summary of Status Report
- Technical Summary
- Acknowledgements and Literature Cited
- Biographical Summary of the Report Writer and Authorities Consulted
Short-tailed Albatrosses are colonial breeders that typically nest on isolated, windswept, offshore islands with restricted human access (Sherburne 1993). Historically, the species seemed to prefer level, open areas adjacent to tall clumps of grass for nesting. Tickell (in Hasegawa and DeGange 1982) described the nests of the species as scoops in the volcanic ash, lined with and built up by grass. Volcanic eruptions in 1902 and 1939, as well as extensive cattle grazing, destroyed much of the original breeding habitat on Torishima. The site now used is on a sparsely vegetated steep slope of loose volcanic soil (Hasegawa and DeGange 1982, Hasegawa 1984). In 1981-1982, native plants were transplanted into the colony, in order to stabilize the remaining nesting habitat and nest structures. Efforts are now being made to establish an alternate, well-vegetated site on Torishima that is less likely to be impacted by lava flow, mud slides, or erosion. There is little documentation of the nesting habitat on Minami-kojima. There is no threat of volcanic activity at this site.
Very little is known of the marine habitat requirements of the Short-tailed Albatross. Specific geographic, seasonal, and age-class distribution patterns within the marine range (see sections below) are not well understood, or remain unknown (e.g. the foraging habitat and ranges of breeding birds).
In general, numerous historic records indicate that the species frequented nearshore and coastal waters, presumably for foraging, and was abundant in the shallow waters of coastal North America. This statement is supported by the high number of bones of this species, relative to the other North Pacific albatrosses, found in middens from California north to St. Lawrence Island (Yesner 1976, McAllister 1980, Lefèvre 1997, Crockford et al. 1997, Crockford 2003). Large numbers of Short-tailed Albatrosses must have ventured close enough to land in order for this species to be so prevalent in the natives’ diets (Hasegawa and DeGange 1982). Recent at-sea sightings in North American waters (Sanger 1972, McDermond and Morgan 1993) also indicate a nearshore tendency, with concentrations along the shelf-break areas in the Bering Sea and along the Aleutian Islands (Camp 1993, McDermond and Morgan 1993, Sherburne 1993, Federal Register 2000). The North Pacific marine environment is characterized by coastal regions of upwelling and high biological productivity, and the observed patterns of Short-tailed Albatross distribution, both past and present, likely coincide with these areas. It cannot be discounted, however, that these patterns are a function of sighting effort. Very little information exists on the distribution of the Short-tailed Albatross in open ocean areas, as these are areas that are seldom visited by experienced observers (Kenyon 1950, Hasegawa and DeGange 1982). It is therefore hard to determine the relative importance of the nearshore marine environment to the species.
In listing the Short-tailed Albatross within the United States, it was deemed that, due to the low numbers of the species relative to historic abundance, it was not anywhere near its marine habitat carrying capacity. The current rate of annual growth (see sections below) suggests that nothing about the species marine habitat is limiting population increase (Federal Register 2000).
Both Torishima and Minami-kojima are under Japanese ownership and management. Of concern is that Minami-kojima has also been claimed by the People’s Republic of China and Taiwan. The dispute is primarily due to the oil resources at the continental shelf near the Senkaku Islands (H. Hasegawa 2001, in litt.). The situation may present logistical and diplomatic problems in attempts to implement protection for the colony, and hinders active research on the island.
The marine range of the species includes different areas of Japanese, Russian, American, Canadian as well as International waters, signifying the complexity and importance of international collaboration in the at-sea conservation of this species (Suryan et al. 2003).
- Date Modified: