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 bj^ the ludicrous 

 bowing performance which looks like a courtshij) 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 

 bj' 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 thej'^ 

 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 fl}' thej'^ 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 Briinnich's mvirre, which still breeds abundantly in 

 Greenland and the far north. 



