88 U. S. BUREAU OF FISHERIES. 



with such poor results that a total of only 2,325 pelts was secured. These 

 latter years mark the most importaut changes in the history of the herd. 



Duing the years preceding 1S96 the foxes had always heen forced to seek 

 their winter food from the summer's accumulation of fur-seal carcasses on the 

 killing fields, and up to the year 1885 had probably secured an abundance of 

 food therefrom. Coincident with the decline of the seal herd, however, and 

 particadarly during the modus vivendi of 1891-1893, which restricted the land 

 killing of seals to 7,500 annually, pending tlie award of the Tribunal of Fur- 

 Seal Arbitration at Paris, the number of foxes became rapidly smaller. The 

 situation, however, was not immediately recognized as a shortage of food, the 

 agents of the Government placing the blame on excessive trapping by the 

 lessees. 



The state of affairs was probably first seen in its true light by Treasury 

 Agent James Judge, who, in the summer of 1896, prepared a quantity of 

 surplus seal meat by lightly salting and storing the food in the manner of 

 ensilage. The experiment was successful, and Mr. Judge immediately recog- 

 nized the possibility of selective killing by catching the animals in box traps 

 instead of the steel traps which had always been used theretofore. A trapping 

 house, with a wire cage adjoining, was the final outcome of the above-described 

 experiment. The foxes came readily to the cage to obtain the much-needed 

 food and were caught when the cagfe door was closed by a rope leading from 

 within the house. 



The methods of trapping outlined in the following pages are based on the 

 Avork of James Judge, to whom much credit is due. That his principle was 

 right and that it has been properly cariied out was shown by the catch of 

 1919-20, when 750 pelts were secured and 454 animals released as breeders; 

 the largest number of skins obtained since 1892-93, and, \vith a single excep- 

 tion, the largest total of animals caught in any season since the inauguration 

 of the present system. 



Food. 



The natural food of the blue fox of the Pribilof Islands is made up of birds, 

 eggs, Insects, berries, miscellaneous bits of animal matter cast up by the sea, 

 and occasionally dead seals, sea lions, walruses, or whales. While such food is 

 plentiful during the milder seasons, it is reduced to the single item of beach 

 food during the winter, when the shore is at times in the grip of frozen spray 

 for long periods. Drift ice also closes the beaches for days at a time and 

 usually large deposits of ice are left stranded, and these hinder the foxes in 

 their search for food. It is at once apparent that comparatively few animals 

 would survive a severe winter without a reserve supply of food. 



In ordinary seasons the foxes of St. George Island are dependent upon a 

 reserve supply of seal meat as food from September 15 to April 30. These 

 dates are very safe and they will, of course, vary as the seasons are mild or 

 severe, early or late, but will in most instances mark the period of need. 

 " Open " or unfrozen beaches during the winter time often furnish much addi- 

 tional food, and during such intervals the foxes feed but lightly on the seal 

 meat. On the other hand, a protracted period of cold prevents the animals from 

 obtaining the natural food of the seashore, and they then visit the feeding 

 ground in large numbers, consuming surprising quantities of meat. This feed- 

 ing is necessary by reason of the fact that there are on the island at the present 

 time many more foxes than the comparatively small supply of natural food 

 in the winter season can support. an»l the size and rate of growth of the herd 

 are primarily limited by the number which can be sustained during that trying 

 period. 



Preparation of food. — Seal meat has been found to be a successful and most 

 readily obtainable food for use as a reserve. The foxes use all the seal meat 

 whicli is not consumed by the native inhabitnnts of the island. After a killing 

 of seals has been made the natives cut up the carcasses, remove the choicest 

 portions for their own immediate and future needs, and the surplus is stored 

 for winter fox food. At a suitable time (usually the day following the killing) 

 the carcasses are eviscerated and emptied of free blood clots to retard putrefac- 

 tion. If large, the carcasses are cut into sections, but if the seals are of a size 

 readily handled they may be stored whole. It is not a good practice to store 

 the meat before it has cooled, nor should it be left on the field through a hot, 

 sunny day. 



The carcasses are deposited in a large pit or silo, which is cut into the side 

 of a hill of hard, scoriaceous earth. The outer side of this pit is bulkheaded 



