112 LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS 



attracting their notice, probably each thinking it is the other that is doing this, 

 but when the discovery is made that there is an intruder about they at once 

 scurry into the farthest end of their hole, which is from 2 to 6 feet long, and 

 there remain quiet. At the end of the hole the nest is situated and is composed 

 of a few coarse grass blades, or oftener of the large flower stems of a plant 

 known to the natives as pooch-ki, and which is eaten by them the natives the 

 same as we use celery. These stalks are from one-half to 1 inch in diameter 

 and often 18 inches long; they are cut into lengths by the birds using their 

 beaks for that purpose. One remarkable thing about these holes is no matter 

 how close they may be to each other no two ever intersect, although they wind 

 in and out, up and down in every direction. Another peculiar and interesting 

 habit is that each hole is supplied with a short side tunnel a foot or so in length, 

 in which the birds deposit their excrement. The nest is always very clean. 

 The love or greeting note mentioned above can be produced, as near as I could 

 get it, by the syllables kwee-kew repeated over and over. In listening to it 

 one could not help thinking of the sound made by a squeaky bucksaw in a 

 splintered log of wood. They also utter a peculiar gnawing, grunting sound 

 which I was unable to put on paper. They are very pugnacious when taken in 

 the hand and will scratch and bite very hard, often drawing blood. For food 

 they are, strange to say, excellent, being the only sea bird with which I am 

 acquainted that is even passable. 



Eggs. The single unmarked egg of Cassin's auklet is between 

 "ovate" and "elliptical ovate" in shape, usually nearer the former 

 and with nearly equally rounded ends, but some eggs are quite 

 pointed at one or even both ends. The shell is smooth, but quite 

 lusterless. The color is dull white, milk white, or creamy white, 

 but the egg shows a decidedly bluish or greenish tinge when held up 

 toward the light. The egg is usually somewhat, and often much, nest 

 stained. The measurements of 60 eggs, in the United States National 

 Museum collection, average 46.9 by 34.3 millimeters; the eggs show- 

 ing the four extremes measuring 51 by 34.5, 45 by 37, 44 by 34, and 

 45 by 31.5 millimeters. 



Both sexes incubate, relieving each other during the night. The 

 universal -rule among sea birds is to raise only one brood during 

 the season, but there is considerable evidence to show that this species 

 is an exception to the rule. The breeding season is much prolonged, 

 from April to November, which means that more than one brood is 

 raised or that the breeding grounds are so overcrowded that different 

 individuals have to breed at different seasons. The former supposi- 

 tion seems to be the more likely. Mr. Walter E. Bryant (1888) says: 



Several young are supposed to be raised during the season. Many nests 

 were found occupied by young in down and one adult bird sitting upon a 

 fresh egg; in some nests the egg was kept warm by contact with the young. 

 In no instance were two old birds found in the same nest, and no birds were 

 found at the time search was made without an egg or young, or both. The ma- 

 jority of the adult birds were females, although both sexes were found sitting. 

 If provoked, either young or old will seize a finger and hold on. The old birds 

 are silent when on the nest, but the downy young make a faint peeping when 

 disturbed. When taken from the nest they endeavor to crawl out of sight, 



