LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 177 
When about 5 or 6 weeks old, long before they are grown or fully 
fledged, they are able to take to the water and they often do so, either 
accidentally or because forced off the ledges by their parents. Be- 
cause of this habit the breeding rookeries are deserted by both old 
and young birds much earlier than would be expected and long 
before the other species that breed with them have left. During 
the last week in July, 1915, I visited Bird Rock to study and collect 
the young of the various species to be found breeding there, but was 
disappointed to find that many, perhaps most, of the common murres 
had left. There were quite a number of very small downy young 
which were still unable to move about much and a few of the larger 
young, about half grown and wearing their soft, juvenal plumage; 
these half-grown birds were very lively and very noisy; evidently 
‘they had about reached the stage where they are ready to leave and 
probably many of them had already left. I estimated that there 
were not over one-quarter as many murres on the rock as I saw on 
my previous visit, but this apparently striking reduction in num- 
bers was probably partially due to the fact that so many had already 
left. 
Various writers have stated that the young birds are transported 
to the water on the backs of their parents or that the old bird carries 
the young, one in its bill, seizing it by the neck or the wing. Both 
of these methods seem improbable, and I can not find an authentic 
account of anyone who has seen it done. Where it is possible to do 
so, the young birds probably scramble or climb down to the water’s 
edge; but where they breed on steep cliffs overhanging the water, 
the following method, described by Gitke (1895), is probably the 
one usually employed; he writes: 
In Heligoland this descent of the young birds from the cliff to the sea is 
accomplished in the following manner: On very fine calm evenings at the end 
of June or the beginning of July one may hear soon after sunset, from a dis- 
tance of more than a mile, the confused noise of a thousand voices, the calls of 
the parent birds, a@rr-r-r-r—orr-r-r-r—errr-r-r-r, and mingled with these the 
countless tiny voices of their young offspring on the face of the cliff, 
irrr-r-r-idd—irrr-r-r-idd, uttered in timid and anxious accents. The old birds 
swim about quite close to the foot of the cliff, and the tone of their incessant 
calls has in it something really persuasive and reasoning, as though they were 
saying in their language, ‘“ Now, do come down, don’t be afraid, it is not so hard 
as it looks,” whilst the little timorous voices from above seem to reply quite 
distinctly, “I can not, I am so afraid, it is so dreadfully high.” Nevertheless, 
in its distress, the little chick tries to get as near as possible to the mother 
waiting for it below, and keeps tripping about on the outermost ledge of rock, 
often of no more than a finger’s breadth, until it ends by slipping off, and, 
turning two or three somersaults, lands with a faint splash on the surface of 
the water; both parents at once take charge of it between them, and swim 
off with it toward the open sea. 
