No. 3.] Reprints and Miscellaneous Notes. I71 



The late Frank Bolles has published some interesting detailed 

 observations respecting the food habits of the Sap-sucker. His con- 

 clusions are :— 



That the Yellow-bellied Woodpecker is in the habit for successive years of 

 drilling the canoe birch, red maple, red oak, white ash, and probably other trees, 

 for the purpose of taking from them the elaborated sap, and in some cases parts 

 of the cambium layer ; that the bird consumes the sap in large quantities for its own 

 sake and not for insect matter which such sap may chance occasionally to contain ; 

 that the sap attracts many insects of various species, a few of which form a consider- 

 able part of the food of this bird, but whose capture does not occupy its time to 

 anything 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 eight Sap-suckers in July andJAugust 1890. Their 

 stomachs " 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 com- 

 posed of the harder chitinous parts of ants. In a cursory examination 1 find little 

 else, though one or two beetles are represented, and No. 4 must have swallowed 

 an entire wasp of the largest size, his heads and wings attesting thereto.^ 



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

 to keep several young Sap-suckers 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 starvation. 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 three Sap-suckers, 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 sufficient 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 eighty. one stomachs, distributed rather irregularly through the 

 year. None were taken in February, March, or November, and only 



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



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



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



l« 



