CONTENTS 



Page 



INTRODUCTION 1 



METHODS 2 



Effects of Animals on Cones 2 



Effects of Animals on Dispersed Seeds 3 



RESULTS AND DISCUSSION 4 



Effects of Animals on Cones 4 



Effects of Animals on Dispersed Seeds 9 



CONCLUSIONS 11 



LITERATURE CITED 13 



(This is a companion report of USDA Forest Service Research 

 Paper INT-86, 1970: "Natural Regeneration in Ponderosa Pine 

 Forests of Western Montana" by Raymond C. Shearer and 

 Wyman C. Schmidt) 



ABSTRACT 



Ponderosa pine ( Pinus ponderosa Laws. ) seed development and sur- 

 vival studies in northwestern Montana showed that small forest animals 

 reduced the potential seed crop very little during the 2-year cone develop- 

 ment period but they consumed an average of 24 out of 25 pine seeds that 

 matured. Red squirrels (Tamiasciurus hudsonicus richardsoni Bachman) 

 harvested an average of 66% of the mature cones, and after the seeds were 

 dispersed deer mice (Peromyscus maniculatus artemisiae Rhoads), chip- 

 munks (Eutamias amoenus luteiventris Allen), and birds consumed the 

 equivalent of an additional 30%. Deer mouse populations apparently fluctu- 

 ated in direct response to the size of the previous year's seed crop. 



