Douglas' squirrels are also called pine squirrels or chickarees. They eat green vegetation, new shoots of conifers, acorns, nuts, mushrooms, insects, fruits, and berries. They are fond of cones and will drop them to the ground and gather them up later for winter storage. They establish favorite feeding stations in the trees. They eat the seeds, which they get to by stripping the cones.
Cone scales mound up on the ground below feeding stations in piles called middens.
The squirrels also stash mushrooms in the forks of tree branches for later use. Douglas' squirrels open acorns by gnawing on the shells. You may find piles of these opened nuts beneath a tree where the squirrel has been working. Common predators include bobcats, foxes, house cats, and owls. Humans raid the cone caches for seeds to be used in planting nursery trees.