As distinct from the buildings of termites (interesting though these are), bird nests offer a more apropos point of comparison for human buildings – they are conducted by single vertebrate (or a few) and can be adapted to varied circumstances, with even a small effect of social learning. However, the basic Bauplan remains species-specific, unlike the creativity of the human architect. Since nonhuman primates lack interesting building skills, and so we suggest that bird nest construction may come to play a similar comparative role for architectural design. The static Bauplan of birds can be compared to the near-stasis of human tool use until the end of the Paleolithic, challenging us to assess the changes in human practice that unlocked an increasingly rapid process of cultural evolution. (#40159)