Birds and Forest Vegetation 513 



Sapsucker had been feeding several large black ants (No. 18), which 

 proved to be Formica fusca. At the same time fresh moist excre- 

 ment was found on a twig adjacent to where the Sapsucker had 

 been seen to void. On examining this with a hand lens I saw it 

 was composed mainly of the chitinous fragments of ants, which 

 proved to be Formica fusca. I then revisited the aspens which had 

 been resorted to so regularly and searched about the base of the 

 trees for further evidence from the excrement. Several samples 

 were taken, some (Nos. 20, 23, 28, and 30) contained Camponotus 

 herculeanus pennsylvanicus, and another (No. 29) contained For- 

 mica fusca. and Lasius niger americanus. I think this direct and 

 indirect information is harmonious and clearly indicates that ants 

 are an important element in the diet of the Sapsucker at this season 

 of the year. Beal ('n, p. 29) says concerning the food of this 

 bird: "Ants amount to 34.31 per cent of the whole food, or 69 

 per cent of the animal part. They are evidently favorite food, 

 being eaten quite regularly through the year, although the months 

 from May to August, inclusive, show the highest percentages, 

 averaging over 68 per cent." (Cf. also Bequaert '22, p. 307). 



All of the species of ants mentioned above, Formica fusca 

 (Linn.) ; Camponotus pennsylvanicus (De G.), Camponotus ligni- 

 perda noveboracensis (Fitch), and Lasius niger americanus 

 (Emery), are known to make nests in rotten wood. The only 

 species known to do serious harm in forests is Camponotus penn- 

 sylvanicus, the common carpenter ant, which tunnels in solid as well 

 as rotten wood. These ants become pests about buildings and are 

 also recorded injuring telephone poles in woodlands. All of these 

 species tend to convert woody tissue into humus, and thus have a 

 general beneficial influence in forests. Recently Hawley and Record 

 ('16) have expressed their suspicions of injury to young white pine 

 about ant nests by Formica exsectoides Forel (authority for the 

 determination of the species not given). (Cf. Haasis '17). Very 

 recently Pierson ('22) has made a very careful study of this ant, 

 confirming the damage done to trees and suggesting methods for 

 its control. In one case Formica fusca (Linn.) was apparently 

 involved. It is very evident that until ants are studied in greater 

 detail, under diverse conditions, we are not in a position to esti- 

 mate safely their ecologic and economic role in forests. Any such 

 investigation should give special attention to the conversion by 

 ants of wood into humus as a method of reducing the fire hazard. 



FERMENTED SAP AND SAPSUCKERS 



The sap drinking habit of Sapsuckers has led to some interesting 

 comments as to the intoxicating influence of fermented sap on 

 these birds. Thus Bendire ('95, p. 85) states: "That it should 

 be fond of the sweet sap of trees does not surprise me, as this 

 contains considerable nourishment, and likewise attracts a good 

 many insects, which the birds eat, but it is not so easy to account 

 for its especial predilections for the sap of mountain ash, which 



