I don't have a link but I believe squirrels do, for the exact same reason: their lives are full of intense intra-species competition, with other squirrels constantly raiding each others' stashes. IIRC squirrels will even deceptively hide acorns if they know another squirrel is watching.

Our ability to understand animal intelligence is limited by or ability to ask appropriate questions, so we tend to underestimate intelligence outside of the primate space.

Here's an excellent book on this topic: https://www.goodreads.com/book/show/30231743-are-we-smart-en...