As far as I can tell, after filtering through a Google search regarding climbing trees, etc....it's just rumor. There are suspect quotes saying the the programmers nixed the idea due to people camping out, the invulnerability of the leaves, etc. The "monkey" perk apparently went the wayside of the other rumored perks like "frogman" and "play dead".
So, unless someone can come up with another answer, or proof, I don't think we'll get them...unless of course public outcry calls for enabling such feats of levity.