Tony: But, to counter your point, don't all weaver birds create extremely SIMILAR nests? Is what we are looking at inventive, or simply variation on a theme?-Thank you for this wonderful point. If weaverbirds set out to invent their nest design in a population of birds, one would expect several different designs instead of all the same, just as weaverbirds are all the same. One type bird, one type nest smells of a designed event.