Birds

Acorn Woodpeckers

Acorn Woodpeckers of the Western US and Mexico store acorns in "granary" trees and defend them aggressively.  They wedge the acorns into holes in trees or wooden telephone poles so tightly that crows, squirrels, and rats can't raid their supply. 

To remove an acorn, a woodpecker hammered it with its bill to crack the shell and extract the meat.

Florida Scrub Jay

These birds cache food by burying one acorn at a time;  if they observe another jay, a potential cache robber, watching them, they will return later to move the acorn.

But they will only do this if they themselves were cache robbers in the past.  Seems that honest jays trust other ones and thieves do not.

Western Scrub Jays are very similar in appearance to our FL Scrub Jays