CAUSES OF DEATH AMONG PUPS. 331 



An effort will be made to make a more definite study of the causes of death among 

 pups. Several causes seem to be apparent on the surface. A certain number of 

 pups are found at a long distance back of the harems. They do not show any marks 

 of violence, and lie prone upon the sand as though they had lain down exhausted and 

 died. Their emaciated condition points to starvation. They have wandered off and 

 become lost. One pup on Polovina was found one-fourth of a mile away from the 

 rookery, evidently starved. Another was seen on the hauling ground, weak and 

 plainly starving. The number that thus stray is, however, not large. 



Another cause of death is the trampling of fighting bulls. The crushed 

 appearance of some of the little fellows and the position in which they lie point to 

 this as the cause. It is not an easy thing to kill a pup, for of the hundreds seen to 

 be run over and stepped upon by the bulls in their lunges about through the harems, 

 no pup has yet been seen to be killed or even seriously wounded. A pup physically 

 weak, injured in some way, or taken in some peculiar position might, however, be 

 easily crushed. 



After the sandy beaches, the next most important place to find dead pups is along 

 the line of the outer harems. This is the ground which is fought over by the harem 

 bulls and the idle ones attempting to steal cows. The case of the dying pup with the 

 crushed head and the pus oozing out seems to indicate a bite by a bull or cow as the 

 cause of death in a limited number of cases. 



The pups as a whole are a very lively, healthy, and vigorous lot of little animals. 

 They climb over the rocks, play with each other in their fashion, and are not at all 

 delicately constituted. No weaklings are to be seen among them. Their instincts 

 seem to lead them to work up the slopes and away from the water, so that drowning 

 must be an exceptional cause of mortality. 



Killable seals do not lie close to or behind the rookeries. Therefore it is not true 

 that in making the drives the breeding seals are disturbed. Behind most of the 

 rookeries are from two to four series of idle bulls, 20 or 30 feet apart, quarrelsome; 

 immovable, and dangerous. Outside of these there are usually as many series of half 

 bulls who will drive a little but stand their ground more or less. Along the water's 

 edge' there is a similar arrangement, but the idle bulls and the wet bulls are closer 

 together. Tolstoi, Zapadni, Eeef, and Polovina, as well as other rookeries lying on 

 slopes or with parade grounds behind, are fringed with these idle bulls, which some 

 early writers took for sentinels. These often perch on huge rocks or sleep in clefts or 

 volcanic craters, wherever they find a suitable place, but they are in no sense sentinels. 

 They merely spend their time in sleeping and watching the rookery life below, in which 

 they would like to take a part but dare not. 



THE CENSUS OP THE EOOKEEIES. 



The estimate of harems made to-day on Polovina rookeries gives us the data with 

 which to complete our census of the breeding herd for the present season for St. Paul. 

 On all the rookeries the harems have been counted except Vostochni and Morjovi. 

 These have been in part counted and in part estimated. For Tolstoi and Polovina 

 Cliffs, Kitovi, Lagoon, Little Zapadni, Zapadni Eeef, and Ardiguen cows as well as 

 harems have been counted. As all the breeding grounds on which cows have been 

 15184, PT 2—6 



