THE AUKS 269 



probably corresponded closely with that of the other member of the 

 genus Alca, the razorbill. 



Auks fly in a straight line with a somewhat bee-like whirring of the 

 wings. The rapid beating of the wings gives the impression of speed and 

 power, but this is illusory, and auks may be seen to make little progress 

 against a strong wind, and are easily outdistanced by the gulls, whose 

 wings beat in a leisurely fashion. The short narrow wings of the auks 

 make the take-off from the level surface of the land or the sea difficult 

 in calm weather. Their whole structure is better adapted for flying 

 under the water; the wings, being then half-open with the primaries 

 more or less closed, form in this position powerful paddles or oars, 

 and the bird moves rapidly through the water. The feet are used in 

 steering movements, turning both in air and water; but not as a means 

 of propulsion under water, except when the bird is moving slowly 

 or "marking time" in its search for fish, or when first diving down from, 

 or coming up to, the surface. 



The lives of many sea-birds are spent in three distinct ecological 

 zones or habitats, which are shared harmoniously or competitively 

 with other species: the feeding and wintering area of the open sea, 

 the collecting or loitering ground (Johnson, 1941) near the breeding 

 site, and the breeding or nesting site itself. The auks, feeding 

 much on the same foods, share the first of these areas between themselves 

 without coming into serious conflict. There are diflerences in feeding 

 habits and in food taken, as we shall presently show; all auks are divers 

 and live by capturing their food principally within twenty fathoms of 

 the surface of the sea. Razorbills, guillemots, little auks and puffins 

 frequently gather in huge dense rafts on the sea below the breeding 

 grounds; this is the second functional area, the loitering or assembly 

 place. The third area, the breeding ground, however, is split up between 

 the species, each occupying its special part, or ecological niche, of 

 the available nesting sites. Competition for territory here is principally 

 between individuals of the same species, less often between individuals 

 of related species. 



The guillemots are the most social of the auks, forming densely packed 

 "loomeries" of thousands of individuals standing or squatting less than 

 a body's length apart; and, in spite of the vocal uproar and gesticu- 

 latory movements, territorial pugnacity (seen in other social species, 

 such as the gannet and the gull) seems to be submerged in the general 

 necessity for mutal tolerance. If guillemots were really pugnacious, 

 each pair demanding the same amount of nesting room (one body's 



