Mature Poplar Comaunify 



Baltimore Oriole 

 ChicKadee 

 Least Flycatcher 

 Ros-bsf<l GrosbeaK 

 W.-llow Thrush 



CctnKer 

 Femes 



Hairy & Downy 

 Wood pec Mrs 



Dicera 

 Saperda 



Ruf fed Grouse 



FIG. 2. Food- web relationships in the aspen parkland of Canada. 

 (After R. H. Bird.) 



