BIRDS AS CONSERVATORS OF THE FOREST. 243 



most notably by plant-lice and scale insects. The former constitute 4 per cent 

 of the year's food, but as they can only be found during the warmer portion of 

 the year, they amount to quite a considerable percentage of the food for those 

 months. Moreover, it must be borne in mind that these soft-bodied creatures 

 are so soon reduced to an unrecognizable pulp in the stomach it is probable that 

 many more are eaten than were positively identified. Scale insects (Coccidae) were 

 also eaten, and several stomachs were entirely filled with them, but like the 

 plant-lice, they are difficult to determine after digestion has somewhat progressed, 

 so that it is probable many were overlooked. 



The Hairy Woodpecker {Dryobates villosus). 



The hairy woodpecker is as common as the downy in most parts of the United 

 States, and to the ordinary observer is only to be distinguished by its greater size, 

 as its colors and markings are very nearly the same. The hairy is a noisier bird, 

 however, and usually makes its presence known by loud calls and other obtrusive 

 behavior, such as rapid flights from tree to tree. Besides the general resemblance 

 of the two birds there is also a remarkable similarity in their food habits, as 

 shown by the contents of their stomachs. The greatest difference is that the hairy 

 eats a somewhat smaller percentage of ants than does the downy. From an exam- 

 ination of 172 stomachs the relative proportions of animal and vegetable food were 

 found to be about 74 per cent of the former to 26 of the latter. 



Beetles, both adult and larval, constitute 24 per cent of all the food, or more 

 than one third of the animal matter. As is the case with the downy, these beetles 

 are mostly woodboring species dug out of the solid wood by the sharp chisel of the 

 bird. Larvae of both the great woodboring families Cerambycidae and Bupresti- 

 dae were identified in most of the stomachs. From one stomach 1 adult and 70 

 larval Cerambycids were taken; from another, 100 larvae; and 50 and 25 respectively 

 were taken from two others. These are samples of what this bird is doing in 

 the work of forest preservation. But it also eats other beetles which prey upon 

 the trees; 109 individuals of Dorytomus mucidus, the snout beetle, that was eaten 

 so freely by the downy, were found in one stomach of the hairy, with 6$ in another 

 and less numbers in several others. Another interesting insect found in the stomach 

 of this bird was Polygraphus rtifipennis, a destructive enemy of the pine tree. 

 Another stomach contained several specimens of Tomicus caelatus, another pest of 

 the forest. 



Caterpillars amount to 21 per cent of the diet of the hairy woodpecker, and are 

 mostly, of the woodboring species, and are all enemies to forest trees. Ants do 



