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 
grinding its food. In winter, when it is difficult to find suffi- 
cient insect food, the Nuthatch feeds in part on such seeds as 
it can pick up. 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 per cent. 
consisted of insects. He found Piesma 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 may 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 were 
recognized, and many beneficial and neutral insects were 
found; but we have seen that the destruction of parasitic 
or predaceous insects by birds is not necessarily or always 
an injurious habit; in Massachusetts several pests are eaten 
by the Nuthatch, and we have not yet recognized in their 
stomachs any large proportion of beneficial insects. This 
suggests the possibility that the conditions in Michigan, when 
the examinations were made by Professor Sanderson, were 
unusual. He notes that he was unable to obtain a specimen 
from any orchard infested with insect pests.! 
1 The Economic Value of the White-bellied Nuthatch and the Black-capped 
Chickadee, by E. Dwight Sanderson. The Auk, Vol. XV., 1898, pp. 145-150. 
