Interrelationships of Ruffed Grouse 207 



has evoh^ed the "Spitfires," "Mustangs," and "Messerschmitts" of 

 the bird world. 



Cooper's and Sharp-shinned Hawks. These two "blue darters," or 

 "bird hawks" are generally common over the Northeast. They are 

 substantially smaller editions of the goshawk, less powerful, and 

 hence less able to take large prey. The Cooper's is the larger of the 

 two and the only one that as a rule can kill an adult grouse. Both 

 birds are notable predators of the young grouse, the sharpshin being 

 the more important on Connecticut Hill due to its greater numbers. 

 McAtee (1935) recorded the Cooper's hawk as having taken grouse 

 in a few cases, but reported no grouse in the nine hundred and forty- 

 four stomachs of the sharpshin examined. McDowell ( 1941 ) found 

 the remains of two grouse in one hundred and eight stomachs of 

 Cooper's hawks from Pennsylvania, these constituting one and eight- 

 tenths per cent of the total food. On Connecticut Hill, the Cooper's 

 hawk was third among the predators of adult grouse, averaging over 

 five per cent of the kills made by predators {N. Y. S. Cons. Dept. 

 Ann. Rep., 1933). 



The data on mortality of the young grouse caused by these hawks 

 are too meager to summarize. The number of chicks taken by them 

 is of some significance. They were clearly the first-ranking predators 

 of the chicks on the study area. The number of remains found in- 

 creased towards late July and in August, but this was at least pardy 

 due to the larger size and more substantial nature of the feathers at 

 that time. 



It is unlikely that grouse ever compose a very high proportion of 

 the diet of the sharpshin, and only in occasional local instances of 

 that of the Cooper's hawk. 



Crow. This "black marauder" is widely renowned as an egg eater. 

 There is little doubt but that crows will raid any nest of eggs they 

 discover, that of the grouse being no exception. The number of 

 grouse nests broken up by crows on Connecticut Hill from 1930-34 

 averaged six per cent of the predator-destroyed nests, but this pro- 

 portion declined somewhat in later years. This record entitles the 

 crow to a place of rather limited importance as a grouse predator. 



On one occasion a flying crow was seen carrying a very young 

 grouse chick. We must thus list the species among predators of the 

 young grouse too, although this habit is surely of small importance. 



