312 



PREDATION 



Over this area during the years studied nest mortality has averap;ed close to 39 per cent. 

 Prior to 1936 it remained within narrower limits than after that date. The greatest diver- 

 gence from the mean occurred in 1936, 1937 and 1940. Yet statistical adjustment hy analysis 

 of covariance for the number of records involved shows that the proportionate losses for the 

 first two of these years were in reality not as low as the percentages indicate I figure 24), 

 while that of 1939 was even lower. In 1940, however, a very appreciable increase did occur. 



Entire State ■ 8° 



Connecticut Hill _ _ 



70 



50 



40 



30 



ZO 

 1931 1932 1933 193+ 1935 1934 1937 1938 1939 I940 1941 



YEAR 



FICLIKE 24. YEARLY VARIATIONS IN GROUSE NEST MORTALITY ON CONNECTICUT HILL AREA AS 

 COMPARED WITH ENTIRE STATE — 1931-1941 



In checking these nests a distinct tendency has been noled for the projjortion destroved to 

 be consistently lower among those in the Adirondack region (table 36). 



TABLE 36. GROUSE NEST MORTALITY RECORDED IN ADIRONDACK REGION— 1931-1942 



Com|)arison of these figures with those of other workers reveals a consid<'ral)le lack of simi- 

 larity, although Gross* found nearly 2.S per cent of the nests broken up on the Allegheny 

 National Forest in Pennsylvania in 1936. King'" icporlcd nesting losses of less than 3 per 

 cent for an area in Minnesota. Chirke'" also ob-ervcd \er\ low mortality in Ontario, stating 

 that he found onl\ one nest to have been (lestro)cd !)) a ])redat(ir. Lacking experience in 

 these localities it is impossible to correlate such widely divergent data. In any case it seems 

 evident that the conditions under which these studies were made must be very different from 

 those in New York. 



• Grot*. L. S.. Circular I.rllcr. U. S. Furcel Service. Allrglicny N'alional Forest. Jiitte IS, 1936. 



