120 



T. H. BLANK AND J. S. ASH 



Table I. Septemher, December and March census, number shot and early 

 and late winter loss, 1949-59 



pair formation is completed) by loss from a variety of causes. Chronologically 

 this loss may be divided into two parts — the early winter loss (between 

 September and December), and late winter loss (between December and 

 March). While certain types of loss (deaths due to accident, predation, disease) 

 are common to both periods, losses due to shooting are the biggest single 

 factor in the early period, and in the latter period loss due to local movement 

 accompanying pair-formation is the major contributory factor. 



Early winter loss has been highest in the four years (1949, i950, 1952, 195?) 

 which have experienced the heaviest shooting pressure and lowest (in 1953, 

 1954, 1956) when shooting pressure was relatively hght. Since the heavier 



4000 



3000 



,2000 ■ 



1000 



1957-8 194901952-3 I950-I 1951-2 1953-4 1956-7 1955-6 1958-9 I959-60 1954-5 

 Fig. 2.— The effect of shooting on December and March population (data in Table 1). 



