Forget nests, humans and their ancestors have clearly had many thousands of years of building things based on our physiological traits of standing upright and dexterous hands. Standing upright means we are open and visible, so we would need shelter and being long distance travelers that aren't huge and tough like cattle we would need the ability to build as needed. Having dexterous hands is mostly an advantage when we use them to make things, so early hominids having opposable thumbs suggests that it was an advantage tied to something like tool creation.

So while the not too distant ice age wiped out most evidence of human culture over 20k or so years ago, it is extremely likely that humanity has been building complex and creative structures for hundreds of thousands of years that has been lost to time. Not to mention the widespread megalithic structures all over the world that suggest a long history of building being widespread cultural knowledge.

Not like ancient aliens lost sci-fi tech bullshit. Just regular old human ingenuity that has helped us live in every climate zone and survive ice ages without needing do develop fur coats like kiss mammals. We have been making our fur coats and shelters and tools for all of those millenia.

Interesting, I didn't think of the tree rings for fine tuning.

How could carbon-14 possibly work for anything half a million years old? That's 87 half-lives!

Ohhh is this the technique where they line up the tree rings with known climate events? It's certainly cool how many different methods they come up with to date things, although judging by the small size of those logs it doesn't seem like they would have very many years to work with.