LIFE HISTORIES OF NORTH AMERICAN DIVING BIRDS. 181 
of 120 feet”; again he says “we are told of guillemots being often 
taken in cod nets in Loch Striven at a depth of 180 feet.” 
The vocal powers of the murre are decidedly limited. The only 
note I have heard it utter on its breeding grounds is a soft, purring 
sound suggested.by its name. This seems to be given in a conver- 
sational tone, as a means of friendly communication. This char- 
acteristic purring sound is constantly heard throughout the breeding 
season on Bird Rock and it is often accompanied by the ludicrous 
bowing performance which looks like a courtship salute but probably 
has no such significance, as it is seen quite as often late in the season 
as earlier; probably it is a sign of nervousness or agitation. While 
several birds are crowded together on a narrow ledge one begins 
by swinging the head and neck rapidly downward in a graceful 
curve until the bill almost touches the rock, one after another the 
others follow suit until all have taken part in the curious salute, 
uttering their soft notes simultaneously. 
Murres might be considered the doves among sea birds, for they 
are the gentlest and most harmless of all. They live in densely 
packed colonies of their own, and closely related species in perfect 
harmony with them; and they are often intimately associated with 
gulls, cormorants, and other species, occupying the same ledges 
within a few feet, or even a few inches, of their neighbors, with 
whom they seldom quarrel, and against whom they are almost never 
the aggressors. On the other hand, they are often the patient, inno- 
cent sufferers from the depredations of their many enemies, chiefly 
the larger gulls, which rob them of their eggs and young. The 
Kittiwakes, I believe, never trouble them. Their worst enemies are, 
of course, human beings, who have for generations killed them in 
enormous numbers and robbed them of their eggs unmercifully, as 
indicated above, until they have been practically extirpated in their 
former strongholds on the Labrador coasts. 
Fall.—The murres leave their breeding grounds as soon as the 
young are able to swim and before the young can fly they begin 
swimming away from the cliffs. The migration consists mainly of 
a gradual movement out onto the open sea where the birds spend the 
winter and this may not be at any great distance from the breeding 
grounds except where ice forces them to travel farther. The com- 
mon murre seems to have been abundant on the New England coast 
in winter in Audubon’s time, but within recent years it has become 
very rare, probably on account of its practical extermination on the 
Labrador coast. There has not been such a marked decrease in 
the numbers of Brinnich’s murre, which still breeds abundantly in 
Greenland and the far north. 
