Any contamination/mutation of food source could cause enforced ingestion of foreign substances.
(I recall a report about birds getting drunk on rotting fruit. It said the sugar was turning to alcohol).
Do you honestly think that
that is a plausible mechanism?
That is, that there is some foreign substance in the nuts that makes the crows find the optimum drop height.
I'll grant you that it is not impossible, and I did ask, so thanks. But, seriouly, do you think that is in any way plausible?
Or do you like it only because it is not-learned and not-evolved? You know, because you're biased against those being the only options...
Science fails to recognize the single most potent element of human existence.
Letting the reigns go to the unfolding is faith, faith, faith, faith.
Science has failed our world.
Science has failed our Mother Earth.
-System of a Down, "Science"
He who makes a beast out of himself, gets rid of the pain of being a man.
-Avenged Sevenfold, "Bat Country"