-66- 



d. Food Habits 



Estimates of the amounts and types of food consiimed 

 by penguins are given in Table 13. This list is not ex- 

 haustive and fails to take into account localized feeding 

 patterns. In rockhopper penguins, for example, Ealey 

 (1954a) found that at Heard Island, amphipods ( Euthemisto ) 

 were a major food item, whereas at South Georgia, Carrick 

 and Ingham (1967) found the diet dominated by krill (E. superba ) 



Sympatric species feeding on the same food items may 

 avoid overt competition for food by eating prey of different 

 sizes, and this must be considered, too. Chins trap and 

 adelie penguins, for example, take krill of significantly 

 different sizes in their overlapping ranges at Signey Island 

 (White and Conroy, 1973) . Finally, much of the data on 

 penguin food habits is limited to that obtained during the 

 breeding season. Virtually nothing is known regarding 

 seasonal diet variation, especially in winter. 



2. Other Seabirds 



a. Distribution 



Seabird distribution in the Southern Ocean (Figure 20) 

 has been extensively reviewed (Voous , 1965; Carrick and 

 Ingham, 1967, 1970; Murphy, 1964; Falla, 1964). Generally, 

 most species occupy a circumpolar zone which changes 

 seasonally (Mackintosh, 1960) . The pattern of seasonal 

 oscillations is largely set by the retreat and advance of the 

 pack ice. Relative species densities primarily of the 

 albatrosses, fulmars, prions, petrels, and shearwaters, 

 are not uniform. In summer, major bird concentrations are 

 in the south Atlantic, the southern Indian Ocean, and along 

 the eastern coast of Antarctica, with notably fewer birds 

 in the south Pacific and western coast of Antarctica 

 (Voous, 1965) . This pattern approximates large Euphausiid 

 distribution in January, February, and March (Marr, 1956) . 



b. Movements 



These species are known to undertake a significant 

 migration analogous to those of whales (Falla, 1964; Ashmole, 

 1971; Carrick and Ingham, 1970; Voous, 1965). Apparently 

 attracted by vast food supplies in summer, large-scale 

 movements of sooty shearwaters, several gadfly petrels, 

 prions, blue petrels and several albatrosses move near the 

 continent, but go north to breed, often to islands near the 

 Convergence (Watson et al., 1971). Oordt and Kruyt (1953) 

 have observed that migrant age structure includes both 

 young of the year and adults. Thus, summer feeding localities 



