Partnership

Something found in nature, but not too common.  This is the result of squirrels storing their food in tree trunks for the winter.  Usually, it's some kind of oak tree.  In this case it's a white walnut or a English Walnut that was stuffed in the base of the host tree.  The walnut wasn't recovered for food, and after some time the walnut takes root and grows in the trunk of the other tree.  It's like a natural grafting.  

In California, acorns and walnuts are natural food sources for squirrels.  I have a Coast Live Oak tree growing in my backyard from an acorn that was buried by a local squirrel.

In this image you can also see that the white tree has been providing food for the Northern Flicker.  A bird that drills holes with its beak in a ring around the circumference of the tree.  The holes are meant to "bleed" tree sap that captures insects. The Flicker returns after a few days or weeks to feed on the trapped insects.  Sort of a harvesting technique.

Go Nature!