PLAN FOR THE MANAGEMENT OF BROWN BEAR 13 



Apparently some bears do not visit the larger and more congested 

 salmon streams. These include very old males too decrepit to defend 

 themselves in the battles staged there, males that have been injured 

 in previous fights and are recuperating in isolation, and females with 

 cubs. The relatively small number of cubs on the salmon streams 

 may be due to the mothers' desire to protect them from other bears. 

 In the bear study of 1932 it was estimated that 10 percent of the 

 bears on the island were not making use of the known salmon 

 streams. 



REPRODUCTION AND SURVIVAL 



Females first give birth to cubs in the third year of life and there- 

 after at intervals of 2 years. The cubs are born in the den during 

 the period of hibernation, and the number per litter is 1, 2, or 3, 

 with a probable average, on a conservative basis, of 1%. Apparently 

 there is a high degree of cub mortality from a variety of causes, 

 including perhaps killing by mature animals. Until better data 

 are available the writers are of the opinion that the survival in the 

 cub crop should be considered as net greater than between 50 and 

 66% percent. 



The life span of the animal is unknown. Ages of 25 years or more 

 are recorded for individuals in zoological parks, but under natural 

 conditions on the range the average may be as low as 15 years. The 

 bearing period in the life of the females is likewise unknown, but 

 is probably at least 10 years. 



ESTIMATED BEAR POPULATION 



The Forest Service and the Alaska Game Commission made a 

 detailed field estimate in the summer of 1932 of the number of bears 

 on Admiralty Island. Four men well acquainted with brown-bear 

 habits and with conditions on the island did the work between 

 August 10 and September 10, when the bears were largely congre- 

 gated along the salmon streams. Every stream of any importance 

 was investigated from its mouth at tidewater to a point as far inland 

 as spawning grounds occurred. The estimators covered 50 distinct 

 areas in detail, and in addition made a few excursions into the in- 

 terior region to determine the number and class of animals that had 

 not come down to the large salmon streams. 



The total estimate for the island was 900 animals. Of this num- 

 ber, 820 were ascribed to areas along the salmon streams and 80 to 

 the vast sections not adjacent to these streams. While the estimate 

 was conservative, no arbitrary reductions were made, and full weight 

 was given to all evidence regarded as reasonably conclusive. It is 

 thought that the total estimate given can be accepted as a basis for 

 starting the game-management plan here presented. The number 

 will be checked from time to time as conditions show the need. 



Practically all brown-bear sections of southeastern Alaska are 

 known to be satisfactorily stocked. Reliable information on this 

 subject is available from forest rangers, game wardens, prospectors, 

 trappers, and other outdoor men who work in this region constantly, 

 and is confirmed by the number found in the detailed estimate on 

 Admiralty Island. Applying the estimated average for the island — 

 one animal on each 1.85 square miles — to the whole southeastern 



