126 CO ACTION: THE INTERRELATIONS OF ORGANISMS 



acorns in white oak and up to a maximum of approximately 50 per 

 cent in black and overcup oak. The nut and fruit destroyers include 

 various weevils, some larvae of other beetles, flies, e.g., apple maggot, 

 various nut weevils, some larvae of other beetles, and moths, e.g., 

 cranberry worm (cf. Weese, 1924; Zazhurilo, 1931). 



Storage by Mammals. The absence of actual hibernation in the 

 squirrels renders some sort of storage desirable if not imperative in 

 regions with much snow. The Abert squirrel and the flying squirrels 

 are thought not to store food at all, though the former appropriates 

 the stores of the Mexican woodpecker, according to Mearns (1907), 

 as does the California gray squirrel those of other woodpeckers. The 

 red and Fremont's squirrels employ stores almost exclusively, hiding 

 them away in hollow trees, in fallen logs, or in the ground. 



The bulk of the cones gathered by the Douglas squirrel are placed 

 in sizable hoards. The simplest type of storage is exemplified by the 

 gray and fox squirrels, and to a minor extent by the Douglas squirrel, 

 which merely bury each nut or acorn singly in the soil. It seems 

 clear that the method by which many of these hidden nuts are found 

 should suffice to disclose most of them, as is indicated by the state- 

 ments of Seton, Morris and Merriam (cf. Seton, 1929:33, 92). It is 

 accordingly probable that the debt of hickories, oaks, and cone bearers 

 to the squirrels has been much overestimated, in spite of Seton, who 

 states that there can be little doubt that three out of five nut trees 

 were planted by squirrels, chiefly the gray (cf. Korstian, 1927:35). 

 The nuts that are not stored away are usually eaten by deer, bears, 

 and other animals. 



In special studies of the reproduction of conifers in the Rocky 

 Mountains, no instance has been seen of buried cones producing 

 sturdy seedlings, owing to the intense competition of the germinules. 

 The seed crop in an even stand of trees, especially a climax, is not of 

 special value as only occasional replacements are needed. It is the 

 cones and nuts in mixed stands at the border lines between the two 

 stages of succession that may be of vital significance. It follows, 

 of course, that they may become effective under various modified 

 conditions in forests. 



The food coactions of squirrels sometimes produce an effect just 

 the opposite to that which is generally inferred. This has been dem- 

 onstrated by tracing the succession after fire in the montane and 

 subalpine forest of Colorado (Clements, 1910). The maintenance of a 

 burn subclimax of lodgepole pine is due primarily to the fact that 

 the population of squirrels, chipmunks, and nutcrackers is driven out 

 by the fire just before an enormous amount of seed is released by the 



