10 



POOD OF WOODPECKERS OF UNITED STATES. 



order of the average amount of animal food contained in their 

 stomachs. 



It is not probable that these relations are absolute in every, case. 

 The position of Sphyrapicus ruber above the two species of Colaptes 

 is perhaps accidental, and the examination of a few stomachs more or 

 less would be likely to change slightly the relative positions. The 

 vegetable food, of course, stands in an inverse ratio to the animal. 

 Mineral matter (sand) is not taken largely by woodpeckers. The 

 most is found in the stomachs of the<flickers, but it is probably picked 

 up accidentally with ants, of which these birds eat great numbers. 

 Ants constitute the largest item of animal food 28.41 per cent, 

 considering the whole 16 species collectively and are actually the 

 largest item in the stomachs of 8 species. The Williamson sapsucker, 

 the red-cockaded woodpecker, and the two flickers take the highest 

 rank in this respect. Beetles stand next in importance, and amount 

 to 20.42 per cent. These two items together form nearly half the 

 food. The remainder of the animal food is composed of insects, 

 with a few spiders, millepeds, and sowbugs, and occasionally a sala- 

 mander, tree frog, lizard, or snail. In the following table is given the 

 average percentage of ants and beetles in the stomach. The species 

 are arranged in the order of their rank as ant eaters. 



