LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 113 
and if tossed into the air they descend quickly and hide themselves from the 
light. They commenced flying this year as early as April 2, and eggs have 
been found as late as November 20, showing a breeding time extending through 
eight months. 
Mr. A. W. Anthony, in his notes sent to Major Bendire, refers to 
a nest “containing a nearly fledged young and an adult female 
incubating a fresh egg; the fledgling was crowded into a branch 
burrow away from the main nest.” Mr. W. Otto Emerson, in his 
notes, states that two or three broods are raised and that he has 
found fully grown young in the same hole with the parent bird sit- 
ting on the second laying. Possibly in all of these cases the young bird 
and the egg may have belonged to different parents, but this hardly 
seems likely, unless the young bird may have been sufficiently 
frightened by the process of opening the burrow to have run into 
a compartment occupied by an incubating bird. If this bird is such 
a prolific breeder as it seems to be this would account for its great 
abundance over such a wide breeding range. 
Young.—Mr. Emerson gives the period of incubation as 21 days 
and Mr. Littlejohn as 30 days. The chick remains in the nest and is 
fed by its parents on regurgitated food until it is fully fledged and 
able to fly. Mr. Emerson says that the young are fed in the same 
manner that a pigeon feeds its young, the parent throwing up a 
thick, creamy, chocolate-colored matter, containing what he took to 
be small marine insects. He says that the young become “ rolling fat 
while in their holes and the old birds are never poor from the cares 
of incubation.” The young remain in the burrows until able to fly. 
Plumages——The downy young is “ Blackish brown” or “ fuscous 
black” when first hatched, fading to “fuscous” or “hair brown” 
when older, on the upper parts; the throat, breast, and flanks are 
paler; and the belly is “ecru drab,” “drab gray,” or “drab.” Ac- 
cording to Mr. Howell’s observations, “ pin feathers begin to show at 
the base of the down when the chick is but 2 or 3 days old. They 
first show through on the underparts, then on the head, and the 
down gradually is shed from the end of the feathers until a small 
tuft below the chin is all that remains.” The first plumage, which 
is thus acquired directly from the downy stage, is not strikingly 
different from that of the adult. The bill is decidedly smaller, how- 
ever, the throat is whiter and the wings and tails are browner in 
young birds. The first nuptial plumage shows no very marked 
change and the young bird closely resembles the adult; birds with 
smaller bills and slightly whitish throats are probably young birds. 
Adults have no conspicuous seasonal changes of plumage, except 
that the fall plumage looks brighter and fresher. The clear, slaty- 
blue and black plumage of adults in the fall, together with the larger 
bills, will usually serve to distinguish them from young birds. 
