LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 143 



on the back. The white increases on the head and underparts, so that 

 in the spring some individuals are largely white below; but in most 

 cases the bellies are more or less clouded with dusky. The wings and 

 tail also fade out to nearly white in the lighter areas. 



A complete postnuptial molt produces the second winter plumage, 

 which is worn for one year. This much resembles the adult plumage. 

 The head and neck are heavily mottled with dusky in the fall, 

 but become pure white by wear and molt during the winter and 

 spring. The back is wholly " gull gray," and the wings are largely 

 so, but there is some dusky mottling on the bend of the wing. The 

 tail is largely white, but there is a subterminal black band, varying 

 in extent in different individuals. The primaries are brownish black, 

 not deep black as in adults, with a large white spot near the tip of the 

 outer and sometimes a smaller one on the second. 



At the second postnuptial molt, which is complete, the adult 

 winter plumage is usually assumed at the age of about 2 years. 

 This is the same as the adult nuptial plumage, except that the head is 

 streaked, the throat is spotted, and the neck is clouded with dusky, 

 all of which disappears at the partial prenuptial molt. The white 

 spaces and gray wedges in the primaries' are not always fully de- 

 veloped in third-year birds, but become more pronounced at suc- 

 ceeding molts. Other traces of immaturity are often retained dur- 

 ing the third winter. 



Food.^-Mr. Turner (1886) gives the following account of the 

 feeding habits of the short-billed gull : 



At Atkha Island, in the early part of August, 18T9, a small species of fish 

 (Mallotus villosus) was thrown up by the waves onto the beach. These fish 

 cast their spawn in the sand and is covered by the next wave. The gulls of 

 this species follow the wake of these fishes, and during the spawning season 

 devour many thousands of them. At Amchitka Island I observed this species 

 frequenting the beach at low tide and securing the sea urchins, which occur 

 plentifully. The birds seize the prey, carry it several yards into the air and 

 then drop it on the rocks, or, as it frequently happens, into the little pools left 

 by the receding tide. These pools are of variable depth, but when of not more 

 than a few inches deep, the bird again took the object to drop it, perhaps into 

 the same place ; evidently not with the intention of washing any objectionable 

 matter from its surface, but simply from the fact that the bird had not yet 

 learned to calculate the law of falling bodies, yet when the shellfish was 

 dropped on the rocks and broken open the bird greedily devoured the well- 

 filled ovaries. These gulls and the ravens frequently carry the shells far to the 

 inland and . there break them open with their beaks, The old shells may be 

 frequently found on a knoll of ground or tuft of grass. 



Doctor Nelson (1887) says that " along the coast of Bering Sea they 

 feed upon sticklebacks and other small fry which abound in the 

 sluggish streams and lakes." Mr. E. A. Preble (1908) found that 

 "three specimens collected May 12 had been feeding on water beetles 

 {Dytiscus dauricus)." Mr. Hersey frequently saw them feedino- on 



