368 The Ruffed Grouse 



man-day coverage, or less, tlie population may be gauged as quite 

 low, the degree by which it falls below the 1.0 average indicating 

 how low. 



It is apparent that population estimates made in late August may 

 not trutlifully portray the condition of October or November. Of 

 course there is a normal loss during September and October that is 

 regularly anticipated, but there may be extra losses that would make 

 the August prediction for fall conditions invahd. However, this is 

 not commonly the case, as most of the serious losses occur in late 

 winter or in summer. Few serious late-summer, early-fall declines 

 have been observed in the East. But there apparently was a serious 

 autumn decline in at least some parts of New York in 1926, and a 

 similar one was observed in Wisconsin in September, 1933. 



In view of the chance of error in depending upon an August brood 

 count for predicting grouse shooting season populations, it is a good 

 thing to check conditions again in October. At this season we can- 

 not use a brood count but must depend upon a time-index of adult 

 flushes. Again the work should be confined to balmy, calm days, 

 and to the best early fall coverts. These are nearly the same as those 

 used in the August count, but with more attention to the overgrown 

 shrub cover, including adjacent orchard and hedge-rows, and a lit- 

 tle less to the slashings. 



The cover should be traversed systematically, as in August, but 

 whereas a close coverage of lines twenty-five to forty feet apart is 

 best for checking broods, lines of fifty to seventy-five feet are more 

 suitable for the autumn work. 



The cover with a normally good brood count in August (two 

 broods per man-day vdth a ten-bird total) would ordinarily result 

 in an average rate of grouse flushes in October of fourteen per man- 

 day, excluding reflushes where determinable. Thus this figure may 

 then be used as a criterion for checking the population at this 

 season. The degree to which the average daily flush total varies 

 from this number may be taken to indicate whether a high popu- 

 lation or a lower-than-good population prevails. If the average flush 

 is seven or lower, the population is low and consideration may be 

 given to curtailment of the harvest. 



It should be emphasized that the validity of the indexes used will 

 depend in good measure upon the conditions under which they are 

 derived, the equahty used in covering the area involved, and the 



