496' Roosevelt Wild Life Bulletin 



can see that after a fire birds and the wind re-seed the soil and 

 greatly hasten reproduction. When once the soil is seeded the 

 maturing of the trees in itself gradually changes conditions until 

 a mature forest is developed. But planting and reproduction are 

 not limited to burned areas alone, for the same process is in opera- 

 tion at all times in the forest, at the forest margin and in the open, 

 and thus many trees are planted. 



The amount of benefit done by the birds in forests is not uniform, 

 but varies greatly with the conditions. In burned areas plantings 

 are perhaps of greatest value, but after reproduction has been thor- 

 oughly established the destruction of potentially harmful insects is 

 probably of greater value. Generally this early vegetation in burns 

 is short lived and is replaced by other kinds of trees in the mature 

 forest, although scattered choke cherry (Primus virginiana) trees 

 may survive even among sugar maple, hemlock and beech. By 

 recalling such facts we are able to see the relative influence or 

 role of birds in hastening the cycle of changes from a burn to a 

 mature forest, and to see how they aid in this change, while at the 

 same time they cause no harm of first importance. 



Influence of Sapsuckers on Forest Trees. As we have seen 

 that the role of birds in scattering seeds on burned areas is a bene- 

 ficial one, I wish now to consider a somewhat contrary influence — 

 the direct injury to trees by a bird, the Yellow-bellied Sapsucker 

 (Sphyrapicus varius varius). In discussing the character of this 

 injury I mean to consider the trees in the order in which they 

 develop after a fire. This is the sequence or succession of refor- 

 estation, and this order is followed because of its importance, and 

 because of the value of a familiarity with this particular sequence. 

 For this reason aspen and birch will be considered first, and later 

 beech, hemlock and other trees that characterize a mature forest. 



South of Camp, about three-quarters of a mile, is a cove or 

 small bay along the shore of which a fire has burned. An extensive 

 strip of aspens has grown up near the water and in this clump of 

 trembling aspens (P. fremiti oides) was found much evidence of 

 injury by Sapsuckers (figure 148). Attention was first called 

 to the injury by a mass of dead leaves remaining on a tree. These 

 dead trees were found girdled in the manner characteristic of Sap- 

 suckers. They had evidently been killed during the season of 

 1915. or the leaves would not have remained on. Other trees were 

 found with the leaves turning yellow, in the act of dying. It was 

 at once seen that the extent of the injury was somewhat unusual, 

 so that a careful search was then made throughout these aspens for 

 other evidences of injury. In all thirty trees were discovered that 

 showed distinct evidences of Sapsucker work. Every stage was 

 found from living injured trees, which had healed their wounds 

 and had recovered completely, to dying, recently dead, and on to 

 dead ones of perhaps a few years standing, with fungi growing on 

 the dead wood (a reddish fundus Tubercularia p'ezizoi'dea S.. and 

 Valsa; determined by Dr. L. H. Pennington) ; and one dead and 

 decaved tree that had been broken by the wind (No. 1). The 



