Actually, eastern gray and other squirrels are fairly serious nest
predators, so it behooves almost any bird to try to get rid of a squirrel
from its nest tree. Smaller birds just can't accomplish this. On the
other hand, it might have nothing to do with this and merely represent the
corvid nature.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416