198 LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS 



sat facing the cliff, but when alarmed they would turn quickly about 

 showing a row of white breasts. Occasionally, without any appa- 

 rent cause and even when we were a long way off, a cloud of birds 

 would leave the rookery, circle around the rocks several times in a 

 steady stream and then quietly settle down again. They became 

 more restless toward night and indulged in these spasmodic flights 

 more frequently, as the population of the colony was increased by 

 the incoming birds. From about 5 o'clock until sunset birds were 

 constantly coming in from their feeding grounds at sea, sometimes 

 in regular formations, straight lines or V-shaped flocks, but more 

 often in loose straggling masses or small bunches. 



The Pallas's murres do not differ materially from their eastern 

 relatives in their breeding habits, in the development of the young, 

 or in subsequent plumage changes. They mingle freely and live in 

 harmony with the California murres. On Bogoslof Island we found 

 a few scattering pairs and several small compact colonies of Cali- 

 fornia murres among them. Both species breed on Walrus Island in 

 the Pribilof group; at the time of our visit there were very few 

 Pallas's murres on this island, but at other times the reverse has been 

 the case. 



Eggs. The eggs are indistinguishable from those of the Brlin- 

 nich's murre, though they average a trifle larger. The measure- 

 ments of 79 eggs in the United States National Museum collection 

 average 82 by 51.5 millimeters; the eggs showing the four extremes 

 measure 91 by 55.5, 73 by 48, and 79 by 47 millimeters. 



Young. Mr. William Palmer (1899) thus describes their method 

 of feeding their young: 



Like probably all their congeners the small young are fed by disgorged 

 crustaceans, but I know that the larger young and even quite small individuals 

 are fed upon whole fish. On August 4 I collected a young murre and also a 

 small fish, a tufted blenny, Bryostemma polyactocephalus (No. 43005, U.S.N.M.) 

 lying at its side. I had previously witnessed the feeding of several others. 

 With the breast to the rock the mother lands, and bending her head downward 

 to her young utters a harsh, croaking sound. The youngster raises its head 

 and, taking the fish from its parent's bill by the tail, works it sideways in its 

 own bill, until it gets the head in its mouth, when the fish rapidly disappears. 

 If the young has had enough, the fish is laid at its side until needed. The 

 fish is carried by the parent with the head partly down its throat, the tail 

 sticking out from between the mandibles. 



Behavior. In their rookeries they live peaceably, as a rule, with 

 only occasional little squabbles, but we once saw a most exciting 

 fight between two birds in the air, a vigorous struggle, so absorbing 

 that they paid no attention to us and fell to the water near our 

 boat, where they continued the battle, both on the surface and below 

 it, with bills, claws, and wings, making the water fly for several 

 minutes, until one had enough and flew away with the other in hot 



