INTRODUCTION 



Red squirrels [Tamiasoiupus hudsonicus riohardsoni Bachman) , deer mice {Pevomyscus 

 maniculatus artemisiae Rhoads) , chipmunks {Eutamias amoenus luteiventris Allen) , and 

 birds consume large quantities of pine seeds, particularly in late summer through spring 

 (Curtis 1948, Eastman 1960, and Smith 1943). Conifer seeds provide an important (but 

 not always reliable) source of food for the small mammals and birds, Ponderosa pine 

 {Finns ponderosa Laws.) and Douglas-fir {Pseudotsuga menziesii var. glauca (Beissn.) 

 Franco), two common associate species in the Northern Rockies, vary considerably from 

 year to year in their seed crops, producing abundant yields in some years and practically 

 none in others (Roeser 1941, Boe 1954). As a result, animals depending upon these seeds 

 are frequently faced with feast or famine; and populations, particularly of the smaller 

 less mobile mammals, may be affected. For example, deer mouse populations in Douglas-fir 

 forests of Oregon apparently fluctuated in direct response to the previous year's seed 

 crop (Gashwiler 1965). Although the feeding and caching activities of small animals and 

 birds have been observed and reported in some coniferous forests of Oregon (Eastman 1960, 

 Gashwiler 1967), little quantitative data concerning seed use in ponderosa pine forests 

 of the Northern Rockies have been collected. This paper discusses (a) how several 

 factors influence the development and production of ponderosa pine seed, (b) how much 

 seed is used by animals, and (c) how much seed is left to regenerate a new forest. 



1 



