Food and Water 129 



fox, and no doubt other species of mammals. The supply of acorns 

 often being exhausted by this heavy drain, these competing species 

 no doubt affect grouse food habits by forcing the birds to shift 

 locally to less palatable foods. Over most of the northeast range, this 

 does not materially aflFect grouse numbers or general distribution, 

 but in the oak-hickory type range from Pennsylvania southward, it 

 probably is a factor in determining tlie carrying capacity for grouse. 

 Chemical analysis of acorns ( Hosley, 1938 ) : water— 2.4 per cent; 

 protein— 7.1 per cent; fat— 4.9 per cent; nitrogen-free extract— 81.0 

 per cent; fiber— 2.2 per cent; ash— 2.5 per cent. Q. rubra (Wright, 

 1940): water— 1.8 per cent; protein— 7.6 per cent; fat— 22.6 per cent; 

 nitrogen-free extract— 61.0 per cent; fiber— 4.8 per cent; ash— 2.2 

 per cent. 



Sumacs {Rhus spp.) 



Species utilized: Dwarf sumac {R. copallina), smooth sumac {R. 

 glabra), poison ivy {R. toxicodendron), staghom sumac (R. ty- 

 phina) (see Plate 24), and poison sumac (R. vernix). All five are 

 staple food producers in parts of the northeast range, and the group 

 as a whole is consistently important over the whole Northeast. Other 

 species also patronized are fragrant sumac {R. aromatica) and 

 lemonade sumac (R. trilobata). 



Seasonal importance: All of the sumacs, including both the poi- 

 sonous and nonpoisonous types, are of value to the grouse in late 

 fall, through the winter, and in early spring. They are utilized to a 

 minor extent in October and May, at the extremes of the season of 

 greatest consumption. 



Parts used: The fruits, heads of which are called "bobs." 



Geographical importance: The sumacs as a group are important 

 throughout the Northeast, and generally to the same degree. The 

 total of Rhus products taken seems to average quite consistently, 

 during the seasons used, from one to six per cent of the food. Geo- 

 graphical variation in importance of the five key species is probably 

 determined in the main by availability. From the records it appears 

 that R. copallina is most used in New York, Pennsylvania, and Vir- 

 ginia, R. glabra in Connecticut, Ohio and Virginia, R. toxocoden- 

 dron in New Hampshire, Massachusetts, and Rhode Island, R. tij- 

 phina in Maine, New Hampshire, New York, Pennsylvania, Ohio 



