Bears are back in the Question Queue, which reminds me of the claim going around Lawrence Berkeley Lab several decades ago.
The claim was that some mother bears in the Sierra would send their cubs up a tree and onto a smallish branch (a branch too small to carry the weight of an adult bear) to knock down a food bag.
My question is: Is there any evidence that this actually happened, or is this apocrophal?
Devising this strategy seems within the scope of the intelligent and experienced bears in Yosemite, but, as far as I know, no one ever claimed to have actually seen mother and cubs implementing it. The closest we came was seeing an adult climb up to a branch, and, holding on to the trunk, reach out and repeatedly whack the branch until it broke, depositing the food bag (ours!) on the ground. No amount of noise deterred it for a second.