ENEMIES OF THE FUR SEAL. 71 
On the island of St. George a complete census of the dead pups for both seasons 
was made. This will illustrate the relative death rate on typical rookery ground from 
more or less accidental causes. The worm is practically absent from the rookeries of 
St. George, which are all located on bowlder beaches. On these rookeries there were 
born in 1896 about 19,000 pups; in 1897, 16,000. The following is the count of dead 
pups by rookeries: 
Comparative counts of dead pups, St. George. 
Rookery. 1896. 1897. 
259 244 
31 84 
112 93 
199 112 
135 15 
736 558 
THE DEPARTURE OF THE SEALS. 
At the first approach of winter, usually in November, the cows and pups go away 
together. The pups are doubtless weaned at this time, as they nurse and subsist: 
solely on their mothers’ milk until the time of their departure. Following the example 
of their elders, they doubtless soon learn to subsist on fish. They have a hard time 
of it the first season by reason of the difficulty of securing food and because of the 
severity of the winter storms. It is pretty clearly ascertained that only about 
one-half return the second spring, and that not more than one-third of those born 
reach the age of 3 years. 
THE ENEMIES OF THE SEAL. 
What enemies the seals encounter on their migrations we do not know. Doubt- 
less the greatest cause of destruction among them is the storms of winter, and these 
affect most strongly the old or injured and the young and inexperienced, which 
possibly fail to secure the requisite amount of food. 
Much has been said about the ravages of certain species of sharks. It is not 
known that any shark preys upon them, in the north at least. The Great Killer 
(Orea orca) is a known source of loss about the islands. Whether the killers attack 
them in the open ocean or not is not known, though it is probable that they do not 
to any great extent. 
THE GREAT KILLER. 
Killers were seen in schools of from three to seven plying about the islands in 
the latter part of September, undoubtedly destroying many pups. These big fish 
swim into the bays, which fairly swarm with seals, old and young, at this time. 
Their course, as they move along the rookery fronts, is marked by hovering gulls, 
which alight to pick up the fragments. The seals seem absolutely stupid in presence 
of the danger. 
On one occasion after a raid by these killers the carcass of a mangled cow 
was found washed up on Zoltoi Sands. On another occasion a killer in heavy surf 
followed the seals into Village Cove and became stranded on the rocks, but another 
