LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 131 
bird in winter is darker above than the adult and lacks the white 
frontal plumes. This plumage is worn all through the winter and 
often through the first nuptial season, though some mottling is ac- 
quired on the breast during the spring and summer. In their first 
summer plumage young birds closely resemble adults, but the bills 
are smaller, lacking the knob, and the frontal plumes are usually 
lacking or very small. Young birds probably do not breed until 
their second nuptial season. At the first postnuptial molt, which is 
complete and is prolonged through August ‘and September; young 
birds become indistinguishable from adults. 
The adult winter plumage resembles the first winter plumage in 
being black above and pure white below, but the black of the upper 
parts is not so intense, the sides of the head and neck are “ plum- 
beous” or “ cinereous,” and the bill is larger, with signs of the nup- 
tial knob; the white frontal plumes are usually present in winter 
adults and are often more pronounced than in spring. <A partial 
prenuptial molt in the spring produces the nuptial plumage with 
the mottled under parts. 
Food.—The food of the least auklet consists mainly. of amphipods 
and small crustaceans which it obtains by diving. Among the Aleu- 
tian Islands, I have seen them feeding a few hundred yards off shore 
but often they fly way out to sea to feed. Considering that the aver- 
age depth of Bering Sea in the vicinity of the Pribilof Islands is 
from, 30 to 50 fathoms, it hardly seems possible that these little birds 
can dive to such great depths to obtain their food on the bottom. It 
would seem as if they must obtain most of their food near the surface 
or in shallower waiter. 
Behavior.—The natives on St. George Island capture large num- 
bers of least auklets for food. During the late evening hours, from 
7 to 10 o’clock, when the birds are returning to their breeding grounds 
in vast numbers after spending the day at sea, it is an easy matter 
for the expert natives to catch them in nets. This custom has been 
well described by Mr. William Palmer (1899) as follows: 
On this vast breeding range of this species, on the 28th of May, I accom- 
panied a native for the purpose of getting a few specimens for myself, while he 
desired a meal. With a large long-handled dip net I crouched behind one of 
the numerous large moss and grass-bedecked rocks which so liberally covered 
the ground. As the birds fly low and in a nearly straight line and have great 
difficulty—in fact, they have little necessity—in making a sudden curve to avoid 
an object, it was only necessary when a flock was seen approaching to raise the 
net directly in their path. If the distance and their velocity had been well 
calculated several birds would be unable to swerve off in time and in, conse- 
quence would be engulfed in the net. A quick bringing of the net to the 
ground would then complete the capture. A half hour’s work resulted in my 
securing some 20 specimens, but the Aleut close by had ten times as many. 
55916—19—Bull. 107-10 
