No. 4.] KKPOin^ OF STA^PE 01IN14M10L0GIST. 351 



pheasants, as well as to other game birds. The English 

 sparrow may therefore become a serious menace not only to 

 l)oultry raising, but to the artificial propagation of native 

 game birds as well. It is but just to say, however, that a few 

 of our native birds carry the same disease. 



The Useful Owl and tlie Pernicious Bird Hawk. 

 The value of the screech owl to the farmer, in contrast to 

 the destructiveness of the sharp-shinned hawk, has been 

 shown by an experience on the writer's place, beginning in 

 1906. In the winter and spring of that year the studies 

 made of the food of a pair of screech owls that were staying 

 in a small grove of white pines near the house at Wareham 

 convinced the writer that they were desirable tenants. The 

 })ellets rejected by them, containing the undigested remains of 

 their food, consisted almost wholly of the bones and fur of 

 house mice, w^ood mice, field mice and mole shrews. The 

 prolific little mice are potentially or actively destructive to 

 trees, farm crops and birds' eggs or young. A nesting box 

 was put out for the owls. This box, as described in " Useful 

 birds and their protection," was of the following dimensions : 

 15 inches high, 11 inches deep and 7 inches wide; the size 

 of the entrance was 3 by 4 inches. In March the owls began 

 to occupy it, and in April they took in a few straws, sticks 

 and other material for a nest, and the female laid and incu- 

 bated five eggs. In due time the eggs hatched, and the 

 parents were kept remarkably busy catching mice and insects 

 for their young all through the spring and part of the sum- 

 mer. So far as we could determine, only a few birds were 

 brought to the nest, — one robin, a red-winged blackbird and 

 two or three jays. As a possible result of the killing of the 

 mice and jays which are known to eat the eggs of the smaller 

 birds, the little songsters of the farm seemed to have unusual 

 success in rearing their young, and there were more small 

 birds about the place in 1907 than in the preceding year. 

 In the spring of 1908 the smaller birds had increased still 

 more, but during our absence a pair of sharp-shinned hawks 

 nested in the most secluded part of the grove. In July the 

 young were found already fledged and flying about among the 



