326 REPORTS OF BERING SEA COMMISSION", 



Arrival of cows, ill July, at wliicli time tlie breeding rookeries 

 attain their maximum size and compactness. 

 Birth of the 8. The COWS givc birth to their young soon 



yotiui>'. . 



after taking their places on the harems m the 

 latter part of June and in July, but a few are 

 delayed until August. The period of gestation is 

 between eleven and twelve months, 

 at^birth^^ "^ ^ "^'^ 9. A single young is born in each instance. 

 The young at birth are about equally divided as 

 to sex. 

 Dcpeiuience of ^Q xiic act of uursiuo^ is performed on land, 



pup upon its ox 



mother. ^ iievcr ill the water. It is necessary, therefore, 



for the cows to remain at the islands until the 



young are weaned, which is not until they are 



Cow suckles four or five months old. Each mother know^s 



her own pup only. 



her own pup and will not permit any other to 

 nurse. This is the reason so many thousand 

 pups starve to death on the rookeries when their 

 mothers are killed at sea. We have repeatedly 

 seen nursing cows come out of the water and 

 search for their young, often traveling consider- 

 able distances and visiting group after group ot 

 pups before finding their own. On reaching an 

 assemblage of pups, some of which are awake 

 and others asleep, she rapidly moves about among 

 them, sniffing at each, and then gallops off to the 

 next. Those that are awake advance toward her 

 with the evident purpose of nursing, but she 



