POPULATION CHARACTERISTICS 



519 



Brood density depends on the number of nests established, their mortality and the degree 

 of renesting*. When nest losses are high, renesting may become quite important. This was 

 apparently the case in several years when the number of family groups found during the sum- 

 mer was greater than otherwise would have been possible in view of the breeding population 

 and the nesting losses observed. On the other hand, there is at times a low abundance of 

 broods in spite of high nest survival, as in 1935 when the data suggest that the degree of 

 breeding failure may have been above average. 



Adult Densities 



The abundance of adult grouse is of especial significance at two times each year — the 

 breeding season and the hunting season. In table 78 are presented the densities attained dur- 

 ing the Investigation over the Connecticut Hill and Adirondack areas. 



TABLE 78. NUMBEH OF ADHIT GHOUSE PEM 100 VCHES ON CONNECTICUT 

 HILL AND ADIRONDACK AllEAS— 1930-1912 



* Certain apparent discrcpanries between figures given in this table antl llinsc 

 fur numerical populatinn eslini.nlrFt quoted in subsequent tables result fmni the 

 (act that the total amount of grouse cover on the Connecticut Hill area in- 

 creased during the course of the Investigation. 



A Represents January 1932 when first census on this area was made. 



Population estimates during the hunting season have not been made regularly. Sufficient 

 work has been done at this season, however, to demonstrate that losses between September 1 

 and mid-October in general are minor. Therefore, data for the end of the brood period 

 (August 31) when the young liirds become adult have been considered representative. 



Comparison of the two areas shows that grouse have been consistently more numerous over 

 the woodlot range of Connecticut Hill. Beyond this, individual coverts have reached still 

 higher levels. Thus in 193.5 the breeding population on a 166-acre unit was 22.3 birds per 

 100 acres while in other instances densities exceeding 15 birds have been recorded. Similarly 

 in the fall a maximum of 38.8 on the same scale occurred over 187 acres at the end of the 

 brood period in 1934. On another unit the figure was 31.5 in 1932 and a number of cases 

 above 20 have been noted. It should be pointed out. however, that these very high densities 

 have invariably been lowered through dispersion to surrounding less well slocked coverts, 

 largely prior to the hunting s«ison. But such population equalization has had no observable 

 effect on the average density for the area as a whole. 



As would be expected the minimum densities noted were associated with the generally low 



* The number of egps per cliilch and the number of cliicks hatching in successful nests have been quite constant. 



