Fascinating. I found a video where two eagles work together to arrange a new stick in their nest. (It takes place around 10:25.) They try multiple spots to see where it fits best. [0]
And unrelated to birds, but hearing about how animals "design and engineer" their living spaces reminds me of the pufferfish, which creates beautiful geometric artwork in the sand as a mating ritual. The fish is only about 4 inches long, but the artwork is over 6 feet in diameter. Picture [1] and article [2].
[0]: https://www.youtube.com/watch?v=9KbtoO6CpQo