Interesting. On the other hand, the existence of all those birds that don't weave hanging baskets for their nests suggests that the oropendula of the Amazon basin is rare - the oropendula is the only bird that does that, as far as I know. Perhaps that behavior is as much a product of geology and catastrophe as biology, as you say.
Many species have some unique aspect about them, or some unique combination of features. Perhaps the only reason we find language and big brains significant is because that happens to be our unique combination of features. If an oropendula could opine about such things, he might very well think the same thing about his nests ;)
