228 



J. G. KING AND G. A. SANGER 



Methods 



Results 



A list of 176 species of birds using marine 

 habitats in or near the States of Washington 

 and Alaska and the Province of British 

 Columbia (Table 1, left column) was compiled 

 from checklists by the American Ornitholo- 

 gists' Union (AOU 1957) and Gibson (1970). 

 Nomenclature is from AOU (1957). The scien- 

 tific names of three species of shorebirds re- 

 cently identified in the Aleutian Islands that 

 were not listed by the AOU (1957) came from 

 Peterson etal. (1967). 



Each bird was scored on 20 /actors that af- 

 fect its survival (Table 1). Point scores for 

 most birds were either 0, 1,3, or 5, indicating 

 no, low, medium, or high importance, respec- 

 tively, in their biology or habits as related to 

 Northeast Pacific oil development. Rare or 

 accidental species were given only one point 

 for occurrence, and endangered species 99 

 points for population size plus 1 point for oc- 

 currence. Thus the potential range of the 

 OVI's is from 1 to 100. 



The factors in Table are largely self-ex- 

 planatory. The items under "range" apply to 

 the entire world population of the species. 

 "Productivity" is derived from a combination 

 of clutch size and age at first nesting. Speciali- 

 zation is used in the biological sense to com- 

 pare a versatile species like mallards (Anas 

 platyrhynchos) with a less versatile species 

 such as the trumpeter swan (Olor buccinator). 

 Mortality under "history of oiling" is based 

 on our knowledge that some species (e.g., al- 

 cids) have been more involved than others 

 such as gulls. Exposure relates to the level of 

 exposure within the Pacific area in any 

 season. 



Information on many of the factors for 

 many species is scanty at best, and subjective 

 appraisals were made by us when information 

 was lacking. Opinions as to appropriate 

 scores will vary among experts. References 

 used, in part, in preparing Table 1 were: AOU 

 1957; Fay and Cade 1959; Gabrielson and 

 Lincoln 1959; Isleib and Kessel 1973; Kort- 

 right 1942; Murie 1959; Palmer 1962; Robbins 

 et al. 1966; Sanger 1972; and Stout et al. 1967. 



The OVI for each of 176 bird species is 

 listed in Table 1. The average OVI for 22 

 avian families comprising 128 species that are 

 neither rare stragglers nor endangered ranged 

 from 19 to 88, with a mean of 51 (Table 3). 



Tables 4 and 5 show a possible use for the 

 OVI by comparing impacts in two large, 

 widely separated areas. A species list from 

 Southeast Alaska (U.S. Forest Service and 

 Alaska Department of Fish and Game 1970) is 

 compared with a list from the Aleutian Is- 

 lands (U.S. Fish and Wildlife Service 1974). 

 Only commonly occurring species are in- 

 cluded. These tables graphically display 

 rather strong differences in the vulnerability 

 of the avifauna of each area. A person explain- 

 ing comparative impacts of projects might 

 use the tables in the following way: 



Column 1, with scores from 1 to 20 points, 

 indicates birds with a low level of project in- 

 volvement, where damage or future costs 

 would not be expected. As this will normally 

 be the longest list, as in Tables 4 and 5, one 

 would expect an immediate rise of interest on 

 the part of the planning agency, which is prob- 

 ably eager to learn where problems will be 

 fewest. 



Column 2 (21 to 40 points) indicates birds 

 for which there is a low level of concern. Per- 

 haps all that is needed is a review to deter- 

 mine if special characteristics of the project 

 might be detrimental to these species. 



Column 3 (41 to 60 points) might be called 

 "trial and error" species. If some birds are ad- 

 versely affected, it will not be catastrophic. 

 As the project develops it will be merely nec- 

 essary to monitor these to make sure their 

 status is not adversely affected. If it is, there 

 will be time to develop conservation 

 measures. 



Columns 4 and 5 (61 to 80 points and 81 to 

 100 points, respectively) include the species 

 where concern is high. It is for these species 

 that research money will be needed, where 

 project modifications may be required, where 

 a contingency plan in case of disaster is 

 needed, where a conservation technology will 



