reduction during this period; they cut nearly half of the cones. Yearly values, how- 

 ever, ranged from a low of 19 percent in 1954 to a high of 82 percent 2 years later, as 

 shown by the following tabulation: 



Cone year Numhei' of cones Percent cones harvested 



1953 128 54 



1954 125 19 

 1955^ 



1956 49 82 



Average 101 44 



Previous squirrel-cutting records reported by Squillace (1953) were based on the number 

 of mature cones available to the squirrels; consequently they were higher, as shown 

 below : 



Yeojc Number of mature cones Percent cones harvested 



1951 



144 



77 



1952 



9 



89 



1953 



80 



85 



1954 



80 



30 



1955^ 







1956 



41 



98 



Average 1953-56 





66 



1951-56^ 





71 



Squirrel- cutting patterns varied from year to year and were difficult to interpret. 

 It was apparent that if mature cones were available, squirrels would harvest at least 

 some of them. However, the amount of their cutting was not necessarily related to total 

 size of the pine cone crop. The size of Douglas-fir cone crops appeared to influence 

 the amoimt of squirrel -cutting activity in the pine. For example, in 1954, fir produced 

 a heavy cone crop and squirrels cut only 19 percent of the pine cone crop. When the fir 

 crop failed in 1956, the squirrels cut 82 percent of the light pine cone crop. In 1953, 

 when fir produced a light crop, a more moderate percentage (54 percent) of the pine was 

 cut. Seeds of Douglas-fir apparently constituted an important segment of the squirrel's 

 diet. 



Although the size of the Douglas-fir cone crop appeared to strongly influence the 

 cutting in pine, other factors might have been involved. Halvorson's (1966) observa- 

 tions on Cedar Island, Flathead Lake, Montana, indicate that squirrels may harvest fewer 

 cones in the moist, cool falls than they do in the dry, warm falls. The small percentage 

 (19 percent) of pine cones harvested by squirrels in 1954, the moderate percentage 

 (54 percent) in 1953, and the large percentage (82 percent) in 1956 support this obser- 

 vation; the fall of 1954 was moist and cool, the fall of 1953 was about average, and 



^None of the cones that would have matured in 1955 survived the first season 

 of development. 



^No cones reached maturity in 1955. 

 ^Includes Squillace's (1953) results. 



7 



