328 



PREDATION 



one bird to 2.5 arres in the fall of 1934. In spite of predator control a higher degree of 

 predation ensued than in surrounding coverts. The great horned owl appeared to be most 

 affected. Hamilton"' has suggested similar movements of weasels in relation to mice. 



Further evidence of the effect of vulnerable excess populations on predator pressure was 

 observed in connection with two lilierations of Reeve's pheasants which were followed by the 

 Investigation. In spite of being placed in an apparently suitable habitat* these birds were 

 completely wiped out within a few weeks, primarily by predation. 



Butt e("S ( r-abbi+s , mice and shrews) 

 Fox AcHviVy 



YEAR 



FIGURE 30. COMPARISON OF FLUCTUATIONS IN BUFFER ABUNDANCE AND FOX ACTIVITY — 

 CONNECTICUT IIIU, AREA ( WINTER) — 1934-1941 



Hut (111- most important relationship observed has been that between foxes and the small 

 mammals which form their principal food supply. Analysis of the frequency of fox tracks 

 as encountered by survey crews from year to year has shown significant differences^. Yet the 

 fox pu|)ulali(>n has appeared relatively stable. Undoubtedly their numbers have fluctuated but 

 there is nothing to indicate that the abrupt changes noted between successive years might be 

 attributed to variations in breeding success or in survival. Neither does it seem likely that 

 the increases observed have resulted from the influx of animals from surrounding territory 



* This in a wnocltand fippcini in its nnlivc rnng<', 

 A Data correUied by aoalyiii u( covariance. 



