260 Alaskan Science Conference 



many of them had become accustomed to feed on the lower, 

 gentler slopes, away from the protection of rough country. Then 

 came the two adverse winters, and heavier wolf pressure, which 

 reduced the sheep numbers and placed them back in rugged 

 territory, where they found greater safety. This meant, of 

 course, a smaller total population. 



In 1920 I found that there was a small group of mountain 

 sheep in the White Mountains, between Fairbanks and Circle. 

 Recently I learned that they are still there. It is significant that 

 after 30 years, in spite of the unprecedented, widely publicized 

 wolf numbers in the north, and living in a place that has had 

 no special legal protection, that handful of sheep has persisted. 



This is precisely the experience we have had in some other 

 places. Large populations have suddenly declined, for obscure 

 reasons, but after reaching a low point they have persisted and 

 in time began a slow recovery. That appears to be what hap- 

 pened in Mt. McKinley National Park, where the numbers are 

 now once more on the upswing. Furthermore, some reports 

 are to the effect that in the Brooks Range, in spite of the wolves, 

 the mountain sheep are holding their own. 



In some of the arid portions of the southwestern United 

 States, where climatic factors severely affect forage growth and 

 consequently animal populations, poaching has in some cases 

 proved to be an upsetting factor that prevented sheep popula- 

 tion recovery. 



The Alaskan moose may in time present a problem, but we 

 have here the advantage that moose are widely distributed and 

 they are not confined to a highly specialized habitat. They do 

 require browse, and it is essential that they continue to have 

 access to areas of heavy willow growth. I shall refer to the 

 moose again later. 



We have a problem with the Alaskan caribou. In 1921 my 

 estimate of the Yukon-Tanana herd was 568,000, and it ap- 

 peared at that time that the caribou of Alaska and Yukon may 

 have numbered over a million. Today the numbers of caribou 

 are reported to be but a fraction of what they were. 



We know that increase in human population, and greater 



