538 



PRODUCTIVITY OF GROUSE POPULATIONS 



The foregoing data refer to conditions under which no hunting was permitted. Yet the 

 sportsman and game manager are more concerned with areas open to shooting. Therefore, 

 what is the effect of such sport on aduh survival? 



Some indication of this relationship was procured when members of the Investigation pur- 

 posely reduced by hunting the grouse population of a 681-acre covert adjacent to the Con- 

 necticut Hill study area. Between October and March 1934-35, 19.5 per cent of the birds 

 present in the fall were so taken. By April a total overwinter loss of 45.2 per cent was recorded 

 as compared with 39.1 per cent for the tract where shooting was prohibited. The following 

 year 10.5 per cent of the fall population was shot, in addition to which a limited amount of 

 public hunting brought the total reduction from this source to about 20 per cent. The ensu- 

 ing winter mortality was 55.8 per cent compared with 43.4 per cent on the check area. In 

 1935-36 after a take for sport of 13.4 per cent the corresponding mortalitv figures were 65.8 

 per cent and 60.5 per cent respectively. In no instance did the difference between total losses 

 on the two plots approach the proportion taken by hunting. It must be borne in mind, how- 

 ever, that the experimental unit was not large and that some birds very likely moved in from 

 nearby coverts. 



Further evidence that moderate hunting seldom seriously affects productivity resulted from 

 the three-year study of a game refuge in comparison with a public hunting ground*. The 

 two were apparently comparable as to cover and any difference in the predator population 

 favored smaller numbers on the refuge due to some control by the caretaker. During the period 

 the number of grouse on the refuge declined steadily. At the same time their abundance on 

 the other tract, although decreasing the second year, rose the following season in spite of an 

 average hunting pressure. 



Final appraisal of this question must await the opportunity to undertake more specific 

 experiments on areas of sufficient extent largely to remove the influence of influx from sur- 

 rounding territory. Nevertheless, the conclusion may be tentatively drawn that on areas open 

 to hunting in the fall approximately half the birds so taken would not survive to breed any- 

 way. Since studies have shown that during the past decade the average proportion of the fall 

 grouse population taken by hunting has been 17 per cenf^ it follows that only about 8 per 

 cent would be deducted from the adult survival which would otherwise occur. One must 

 remember, however, that these data have not covered a period of general decline in grouse 

 abundance. 



« See Chnl.l'f 'X. I'- 391. 

 ^ Sec Clinplir IX. p. 378. 



