174 USEFUL BIRDS. 



erally .seem to have overlooked this habit. The slightly 

 upturned bill of the Nuthatch, and its habit of hanging up- 

 side down, give it an advantage when in the act of prying 

 off scales of bark under which many noxious insects are 

 secreted. 



The food of this bird consists very largely of insects, al- 

 though it is capable of subsisting on seeds, for it has a strong- 

 muscular gizzard, and consumes much sand or gravel for 

 o-rindinof its food. In winter, Avhen it is difficult to tind suffi- 

 cient insect food, the Nuthatch feeds in part on such seeds as 

 it can pick u}). Oats and corn are then eaten wherever they 

 can be found. 



Prof. E. Dwight Sanderson, who examined thirty-four 

 stomachs of this species taken in Michigan, found many 

 seeds, among them ragweed and wild sunflowers. The birds 

 had eaten seeds in winter to the amount of sixty-seven and 

 four-tenths per cent, of the stomach contents, while the re- 

 mainder consisted of gravel and insects ; but in early spring- 

 only thirteen and five-tenths per cent, of the food was of a 

 vegetable nature, while seventy-nine and five-tenths i)er cent, 

 consisted of insects. He found Piesrna cineria the most 

 common noxious insect in these stomachs. This insect, as he 

 remarks, " never does any considerable injury." Its frequent 

 presence in the stomach of the Nuthatch ma}^ possibly explain 

 why it is not more injurious. Although seven orders of 

 insects were represented in these stomachs, Professor Sander- 

 son regards the birds as neutral, for no first-class pests ^vere 

 recognized, and many beneficial and neutral insects were 

 found ; but we have seen that the destruction of parasitic 

 or ])redace()us insects by l)irds is not necessarily or always 

 an injurious habit ; in ]\Iassachusetts several pests are eaten 

 hy the Nuthatch, and we have not yet recognized in their 

 stomachs any large proportion of beneficial insects. This 

 suoforests the i)ossibilitv that the conditions in Michigan, Avhen 

 the examinations Avere made by Professor Sanderson, were 

 unusual. He notes that he was unable to obtain a specimen 

 from any orchard infested with insect pests. ^ 



' The Economic Value of the White-bellied Nuthatch and the Black-capi)eA 

 Chickadee, by E. Dwight Sanderson. The Auk, Vol. XV., 1898, pp. 145-150. 



