THE PROBLEM OF CONTROL 345 



THE PROBLEM OF CONTROL 



Early in this chapter it was stated that if, through predator control, the game manager 



could produce a greater fall surplus of grouse and the hunter be enabled to harvest it 



better sport would result. Whether or not measures of this kind will have such an effect 



can only be determined by actual trial in the field. The Investigation has carried on a 

 few experiments of this nature. 



Experiments Conducted 



The first series of tests were made on land being surveyed in connection with the Con- 

 necticut Hill study area. The tract to be used was divided roughly in half, 1,425 acres of 

 grouse cover to 1,223 acres. Beginning October 1, 1930. an attempt was made to com- 

 pletely eliminate all predators from the former portion although this goal was never 

 attained. The other portion was used as a check. Nevertheless, between that date and 

 August 31. 1932. a total of 557 individuals was taken*. 



Following this Nature was allowed to take its course for a year. Then between October 

 1, 1933 and April 30, 1934 elimination of predators was again attempted. This time the 

 other jjortion of the tract was subjected to coiitri)! since there was a possibility the results 

 obtained previously were unduly influenced by j)cruiiaritiei of the coverts chosen. During 

 tliis |)criod 195 spciimens were removed*. 



Because the inilial experiment had been most effective in reducing nest losses and because 

 foxes and weasels had been found the most important nest predators, the selective control of 

 these two species oidy was a logical stej). This was first undertaken during the winter and 

 spring of 1933-34 on a nearby area known locally as Hull Hill. The results, however, were 

 inconclusive since even these animals were not successfully eliminated. Accordingly this se- 

 lective practice was repeated on a portion (792 acres) of the test tract on Connecticut Hill 

 from October 1, 1934 to April 30, 1935. During this time 18 red foxes, four gray foxes 

 and two weasels were taken. 



Beyond this the fall of 1934 on this area witnessed the highest grouse density recorded 

 by the Investigation — an average of a bird to 2.5 acres over a 187-acre covert. Even 

 though this was a ])art of the area on which long-time population trends were being fol- 

 lowed it seemed too good an opportunity to pass up. Intensive control of all predators was 

 therefore instituted to determine to what extent such a level of abundance could be main- 

 tained. From ()( lober 1. 1934 to April 30, 1935 a total of 97 predatory birds and mammals 

 were renu)\c(l from this covert*. 



This completed the trials carried out direclb by the Investigation. Throughout all of 

 them the usual grouse survey field work was carried on at all seasons on both the control 

 and check portions. 



In 1940 a .separate project to study this problem was established within the Bureau of 

 Game under the provisions of the Federal Pittman-Robertson Wildlife Restoration Act. As 

 a study area. Valcour Island of 1050 acres, lying about a mile from shore in Lake Cham- 

 plain, was chosen. A low population of grouse was present here as well as varying hares 

 and cottontail rabbits. Complete elimination of predators was instituted and its effect on 

 grouse and other species followed carefully. 



* A summary by species is inclu<led in the Appendix, p. 875. 



