M 



THE AUDUBON BULLETIN 



Fig. i 

 Pine Cone Gall 



Fig. i-A 



Cross Section 



Pine Cone Gall 



Fig. i — Sunflower Gall 



Galls have an attraction for certain birds. 

 They have learned that they contain many a 

 choice morsel. 



The pine cone galls (Fig. i), common upon 

 the twigs of willows, are veritable food store- 

 houses. I have seen chickadees and goldfinches 

 in winter, perched upon them, tearing them apart 

 to get at the insect food hidden within. 



Fig. i -A shows a cross section of the pine 

 cone gall. 



Besides the gall insects, the birds find grass- 

 hoppers' eggs underneath the scales of the gall. 

 I removed 103 such eggs from a gall which had 

 previously been examined by a bird. 



The apical galls on the woodland sunflowers (Fig. 2) are also sub- 

 jected to close scrutiny by birds. These galls, too, are depositaries for 

 grasshoppers' eggs. 



Another gall which is common upon the branches of the white oak, 

 is the oak bullet gall (Fig. 3). These spherical galls are of a corky sub- 

 stance, in the center of which is a small thin-walled chamber containing 

 the gall insect. They are eagerly sought by the birds who open them to 

 extract the fat larva or the mature insect. 



The galls on the stem of the giant ragweed also attract birds. I 

 have seen woodpeckers diligently tapping the walls of this insect dom- 

 icile until the occupant was dislodged by the feathered raider. 



Other galls attacked by woodpeckers are the goldenrod ball galls, 

 and the twig galls on willows and poplars, the first caused by gall flies, 

 the other two by beetles (Fig. 4). 



