I recently watched a wild weasel, and learned something that should have been obvious: they are excellent tree climbers! Not "they can eventually make it up a tree", but almost "custom designed for the purpose".

This makes sense, as they are closely related to martens, who are agile enough in trees to chase down and eat grey squirrels[1]. But somehow I'd never made the connection, and had thought of weasels as ground-bound.

[1] https://theconversation.com/resurgent-pine-martens-could-be-...