30 THE FOOD OF WOODPECKERS. 



thing like the extent to which sap drinking occupies it ; * * * that the forest 

 trees attacked by them generally die, possibly in the second or third year of use; 

 that the total damage done by them Is too insignificant to justify their persecution 

 in well-wooded regions. ' 



Mr. Bolles shot 8 Sapsuckers in July and August, 1890. Their stom- 

 achs "were well filled with insects." Some of these were examined by 

 Mr. Samuel H. Scudder, who states : 



The insects in the different stomachs are in all cases almost exclusively composed of 

 the harder chitinous parts of ants. In a cursory examination I find little else, though 

 one or two beetles are represented, and No, 4 must have swallowed an entire wasp 

 of the largest size, his head and wings attesting thereto.^ 



In a subsequent article Mr. Bolles gives the result of an attempt to . 

 keep several young Sapsuckers alive on a diet of dilute maple sirup. 

 Unfortunately for the experiment, the birds obtained and greedily 

 devoured numerous insects attracted to the cage by the sirup. How 

 many of the insects were eaten was not known, but all of the birds 

 died within four months. Examination of their bodies showed fatty 

 degeneration of the liver — a condition said to be usual in cases of star- 

 vation. Mr. Bolles states : 



The most probable cause of this enlargement of the liver, which seems to have 

 been the reason for the death of the 3 Sapsuckers, was an undue proportion of 

 sugar in their diet. In a wild state they would have eaten insects every day and 

 kept their stomachs well filled with the chitinous parts of acid insects. Under 

 restraint they secured fewer and fewer insects, until, during the last few weeks of 

 their lives, they had practically no solid food of any kind.' 



Mr. Bolles has thus proved by experiment that concentrated sap 

 (saturated with sugar) is not suflQcient to sustain life, even with the 

 addition of a small percentage of insects. The logical inference is 

 that sap, while liked by the birds and consumed in large quantities, 

 holds a subordinate place as an article of food. 



The Yellow-bellied Woodpecker is represented in the collection by 

 81 stomachs, distributed rather irregularly through the year. None were 

 taken in February, March, or November, and only a few In January, 

 June, and December; the great bulk were collected in April, August, 

 September, and October. They were obtained from 15 States, the 

 District of Columbia, and Nova Scotia. All were from the Northern 

 States, except a few from North Carolina, Virginia, and the District of 

 Columbia. Unlike any of the preceding species the vegetable element 

 of the food here exactly equals the animal part. The insect matter 

 was made up of ants, wasps, beetles, flies, bugs, grasshoppers, crickets, 

 and mayflies. Some spiders also were present. Of the whole food, 36 

 percent consisted of ants, a higher percentage than in any other wood- 

 pecker except the Flicker. Beetles amounted to 5 percent, and do not 

 appear to be a favorite food. Flies {Biptera) in various forms were 



1 The Auk, Vol. VIII, July, 1891, p. 270. 

 ''The Auk, Vol. VIII, July, 1891, p. 269. 

 3 The Auk, Vol. IX, April, 1892, p. 119. 



