190 BIRDS IN THEIR RELATIONS TO MAN. 



from that of its congeners : it is only slightly extensile and is 

 not adapted for penetrating the channels of and dragging 

 forth wood-boring larvae. Consequently these pests are 

 seldom found in its food. Its usual diet appears to consist 

 of insects and berries of various sorts, together with the sap 

 and more or less of the inner bark (cambium) of trees. 

 Like the flicker it takes great numbers of ants, the other 

 insects eaten including beetles, crane-flies, grasshoppers, 

 caterpillars, and bugs. Fifteen out of thirty Wis- 

 consin specimens had eaten nothing but ants. Of 

 berries, wild grapes and dogwood-berries are de- 

 voured. 



There can be no question that the yellow-bellied 

 woodpecker habitually feeds upon the sap of trees : 

 the testimony of naturalists and fruit-growers in 

 many widely separated localities is conclusive on 

 this point. To obtain the sap the birds make 

 horizontal series of punctures in the bark of many 

 trees ; these holes extend through the bark and 

 slightly into the wood. They are deeper than those 

 made by the downy woodpecker and run horizon- 

 tally around the tree, a half-inch or more apart. 

 Two or more series, one above the other, are usu- 

 ally made in the trunk of the chosen tree. The sap 

 oozes into these holes and the birds revisit them 

 constantly to suck it up, just as the owner of a 

 sugar-orchard visits his pails to gather the sap from the maple- 

 trees. During recent summers we have repeatedly seen these 

 birds thus visiting the hundreds of punctures they had made 

 in a row of English white birches along the border of Dart- 

 mouth College park. The woodpeckers were by no means 

 the only visitors attracted by the flowing sap : humming-birds, 

 hornets, wasps, flies, and ants were there in abundance. The 

 two first named were not on good terms, for whenever a ruby- 

 throat would appear, one or more of the great white-faced 



