500 Roosevelt Wild Life Bulletin 



the leaves curled, but not turning yellow, as they sometimes do. 

 This tree had been completely girdled over an area of six inches 

 of the trunk. This injury had reinforced an older one of the 

 same kind that extended around nearly half of the stem. Although 

 the girdling of the tree (No. 2) was very severe, healing had made 

 considerable progress and the leaves were yet green when the tree 

 was cut. 



In August, 1916, I again visited this same clump of aspens 

 (figure 148), went over the area in more detail than on the previ- 

 ous year, and found two dead trees (one with brown leaves on), 

 22 injured (9 severely), and four cases doubtful as to cause of 

 scars. To my surprise no fresh injuries were observed in this 

 place. One tree two inches in diameter was irregularly but com- 

 pletely girdled five feet from the ground, over a six-inch zone, 

 yet looked in good, condition. 



I wish to refer to only one other kind of influence of the birds 

 in this colony of aspens and that is to the growth of lateral buds 

 or suckers that develop below the girdling of the stem after the 

 upper part dies. I found several good examples of this (Nos. 7, 

 18, 19, 20, 21 and 22) in 1915, and one (No. 21) in 1916. A small 

 tree, hardly larger than a lead-pencil, had been severely girdled 

 for about ten inches of its stem, and large rectangular patches of 

 the bark had been removed rather recently. Below this injury a 

 big sucker developed, bearing much larger leaves than correspond- 

 ing ones on the normal tree (figure i5oe). Two good examples 

 of these suckers are shown in figures I49e and f. I examined a 

 large colony of aspens in search of larger trees whose tops had 

 been killed but whose suckers had developed and had thus formed 

 a new stem. I found two with bent stems, but no evidence 

 remained to indicate that the stem had been killed by Sapsuckers. 



One tree (No. 21) with dead and dry brown leaves on it, had 

 been severely girdled, and some of the bark and wood above the 

 injury was yet green. This tree was \ T /\ inches in diameter 4 

 feet above the soil, and the injury began at 34 inches above the 

 ground, but the girdling proper at 37.5 inches, and extended along 

 the trunk for 10 inches. A large sucker grew out at 15.5 inches 

 above the ground, grew for about a foot and then had died at 

 the top. 



Many of the small aspens about the Camp showed a few holes 

 made by Sapsuckers in 1915, but in August, 1916, a clump of 

 small trees at the south part of the Camp were the scene of con- 

 siderable Sapsucker activity (figures 151 and 152.) Four trees 

 were specially noted. Tree No. I, which was 2.5 inches in diameter 

 4 feet from the ground, was injured 7 feet from the ground, and 

 the injured zone extended along the trunk for about 2 feet. 

 No. 2 was 3.5 inches in diameter 4 feet above the ground, the 

 injury began at 6 feet above the ground and extended upward 

 about 30 inches, but was mainly concentrated in the first foot. 

 The lower 4 inches, the older injury, was constricted and dried 

 out. while the upper 8 inches was somewhat enlarged and was 



