First thought when reading the title was that it will look very fragile and clumsy when walking (even real birds do) and that was confirmed by the first video. What's the purpose of actually mimicing bird legs and feet? Why not use something more simple like wheels on a board that has a spring for example? I expected the article to justify why, but to me it seems like the big thing was the jumping itself, which does not require complex bird anatomy necessarily. There's probably a good reason that I missed, but this feels like a too direct translation of the bird feature, unless the purpose is specifically to make it look and move like a real bird.