Birds and Forest Vegetation $11 



to feast upon the insects that have been attracted to the spot by the 

 escaping sap. This bird, then, by a few strokes of its bill, is en- 

 abled to secure both food (animal and vegetable) and drink in 

 abundance for an entire day; and a single tree, favorably situated, 

 may suffice for a whole season ! " 



Frank Bolles ('91, '92) also made very interesting observations 

 on the feeding habits of these birds in New Hampshire, as is shown 

 by the following quotations ('91, pp. 257-258) : " The tree most 

 recently tapped was a red maple about 40 feet high and 2 feet 

 through at the butt. The drills made by the Woodpeckers began 

 18 feet above the ground and formed a girdle entirely around the 

 trunk. The girdle contained over 800 punctures and was about 3 

 feet in height. In places the punctures or drills had run together 

 causing the bark to gape and show dry wood within. The upper 

 holes alone yielded sap." He concludes (p. 270) : " 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 birds con- 

 sume 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 

 considerable part of the food of this bird, but whose capture does 

 not occupy its time to anything like the extent to which sap drink- 

 ing occupies it; that different families of these Woodpeckers occupy 

 different ' orchards,' such families consisting of a male, female and 

 from one to four or five young birds ; that the ' orchards ' consist 

 of several trees usually only a few rods apart and that these trees 

 are regularly and constantly visited from sunrise until long after 

 sunset, not only by the Woodpeckers themselves, but by numerous 

 parasitical Hummingbirds which are sometimes unmolested, but 

 probably quite as often repelled ; 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." 



McAtee ('11) has made an elaborate study of the influence of 

 this Woodpecker on trees and wood, and records (p. 53) that: 

 " Twenty-nine of these trees and one vine are known to be some- 

 times killed and twenty-eight others are much disfigured or seri- 

 ously reduced in vitality." 



The kind of food and drink utilized has been given considerable 

 attention by Beal ('95, 'n). Sap, bast and cambium are the main 

 food elements. An examination of the stomach contents of more 

 than 300 birds by Beal ('11) shows that the food is about half- 

 and-half animal and vegetable. The vegetable food consists largelv 

 of wild fruit and cambium. In April cambium may amount to 

 nearly half the bulk of the food. It eats a large amount of wild 

 fruit, and thus is an important agent in the scattering of tree and 

 shrub seeds. The tree seeds eaten are those of red cedar, hack- 

 berrv. sassafras, choke cherry, black cherry and sour g;um. Sev- 



