Yes, to be pedantic about it, but I didn't say "send birds" or "do exactly what birds do", I said to look to them for ideas. Eliminate every extra gram, optimize aerodynamics and control for the purpose (c.f. owls vs. quail vs. hummingbird vs. woodpeckers) and go from there. Don't try to build a flying machine around power source that is essentially a hunk of dense metal.