I don't understand how this kind of thing is a revelation. I see myself easily able to do the exact same thing without really even thinking about it when I eat peanuts, it requires no advanced thought to sort through things like that. It just requires you to be in-tune with how an object reacts slightly differently when the weight and balance of an object varies. There are studies that show that your finger tips have a sort of memory, so you can forage through a bag or chips and find the best ones without even taking yourself out of the movie you're watching. An animal being able to do something similar doesn't strike me as astonishing in the least.
These kinds of findings always make me imagine an anthropomorphized version of that animal who watches as we "discover" something new about them.
"We've been putting sticks into holes in rotting logs to pull out ants for centuries and you guys are just now recognizing that as using a "tool"?" Says an Orangutan, "Have you been living under a rock?"
There was an episode of NOVA Science Now (which I love) but they had the host listen to the scientist in the segment pour two cups of water. One was cold water and one was piping hot. The host was amazed that he was able to determine the difference just by listening to the sounds of the two samples of water being poured.
Advertisers have known that there is a different sound for decades and they use that sound in commercials to help entice you into purchasing a cool glass of Coke or a hot cup of coffee. And writers I'm sure have noted the specificity of the sound before to paint a clearer picture of a scene.
It is absolutely amazing that we can decipher these subtle things in our environment; that our brains notice slight differences in sights and sounds that don't really even register in our conscious thought. It's amazing that our fingers have a sort of memory that aids our ability to perform tasks that require a strong tactile awareness. It's astonishing that our neurons fire in sync so that we may walk properly, let alone to think that when we walk on rough terrain, our brains then make calculations based on sight, feel, and positional awareness, that allow us to adjust to any terrain in a split second. And knowing that about ourselves, I think it's not that difficult a leap to then look at an animal running across rough terrain and recognize the same amazing abilities in that animal. Seeing such abilities in animals is absolutely amazing when you consider all those cells and systems working together to do it and that we all share much of the same stuff in our bodies that let us all perform such tasks.
But it is laughable to think that we've "discovered" something like a bird shaking a nut to feel the heaviness of it, thus allowing it to make a better decision on which nuts to spend time cracking open. I can, by just the feel of them, determine which pistachios are going to be a pain in the ass to open. The bird has been doing that since it evolved and that trait probably existed in the bird's predecessors for millennia prior to that particular bird. The only thing we did was notice something that has been going on pretty much forever. This is not like a biological discovery that required finer and more precise instruments… this isn't some new theory of everything that required countless hours of thought and calculation… this isn't some new look into a black hole that only was able to occur after an incredible new advance in technology allowed us to find a particle only thought to exist before. No, this is just noticing a behavior.
Do we find it amazing that lions are easily able to filter through an entire herd of antelope and determine which ones they are the most likely to catch? No, because it's never been looked at in that way… we've seen the pattern that the predator goes for the weakest prey. We've seen and recognized that pattern for centuries, but i've never heard anyone consider how miraculous an ability that is and considering how it relates to the brain of cats. It's the same kind of processing as the birds deciding what nuts to eat, it's just the lions are processing visual information and the birds are processing tactile information.