LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 167 
Bowdoin Bay, September 6; and eastern Greenland, latitude 78° 20’, 
September 3. 
Egg dates—Hudson Bay: 6 records, June 10 and 21, July 6, 7, 10, 
and 24. Cumberland Gulf: 2 records, June 28 and July 2. Green- 
land: 1 record, July 4. . 
CEPPHUS COLUMBA (Pallas). e 
PIGEON GUILLEMOT, 
HABITS. 
From the painted caves of the Santa Barbara Islands northward 
to the bold rocky islands of northern Bering Sea we found the pigeom 
guillemot, the Pacific coast representative of our familiar “sea pig- 
“eon,” everywhere common in the vicinity of rocky shores or high 
precipitous cliffs, where it finds congenial summer homes. South of 
the Aleutian Islands and the Alaska Peninsula it is present through- 
out the year, but there is a decided migratory movement north of 
this line and probably a less noticeable migration throughout its 
range. : 
Spring.—F rom its winter wanderings, at sea or along the coast, it 
returns in early spring to its breeding grounds. In the Commander 
Islands, according to Stejneger (1885), this occurs as early as the 
middle of March, and farther north as soon as open water can be 
found. On their arrival at their breeding grounds the birds con- 
greate about their favorite nesting sites, but are in no hurry to begin 
laying. Egg laying does not begin on the California coast much 
before the middle of May, and in the Aleutian Islands not before 
the middle or last of June. During the mating season the males 
indulge in many little squabbles and even vigorous combats. Daw- 
son (1909) describes the encounter as follows: 
A cockfight between rival suitors is apt to be quite a spirited affair. As 
they face each other upon the surface of the water, the combatants hold their 
tails, inconspicuous at other times, bolt upright; and this, with their open 
mandibles disclosing a bright-red mouth and throat, gives the birds a some- 
what formidable appearance. The actual scrimmage, however, is likely to take 
place beneath the water rather than upon it; and the onlooker has no means of 
guessing the battle’s progress till the weaker bird bursts from the water like a 
flying fish, and so by change of scene gains a momentary advantage of his. 
pursuer or owns defeat outright. 
Nesting.—In the precipitous rocky cliffs of the Santa Barbara 
Islands are numerous large, deep caverns, worn away by the action 
of the waves, which have for unknown ages been pounding at the 
foundations of these solid walls of rock and carved them into fan- 
tastic shapes. At high tide or in rough weather most of them are in- 
accessible, but under. favorable circumstances some of them can be 
explored in a boat or even on foot in safety. In the “ painted caves” 
