From this article we may deduce one of two possibilities. Either no serious researchers have been looking in the Amazon for new birds until now. Or, evolution continues unabated where the process is left to occur in pockets of the planet which remain undisturbed.
These pockets may be very small; fortunately the Amazon is a big place. At the moment it's under serious threat from companies, governments and desperate farmers grubbing for more of those unsustainable resources we know to be less important than the welfare of the planet as a whole - National Geographic puts the case succinctly here: Rain Forest Threats
Evolution happens, it's not a myth and it's very necessary to the universe as a whole. The discoveries we make across all spheres of science may be linked to it, and in some instances we may create new opportunities for evolutionary process inadvertently, as in the growth of the Particle Zoo. But in the natural world, the last thing an evolving process would need or want is to be caught in the midst of transformation by a species with a global reputation for whimsical destruction.
We really don't need to be rocket scientists to work out that the human race hasn't made a very good name for itself on the universal level. We still, as the Asgard put it, have "great potential", but we are yet to awaken that potential by respecting the planet on which we exist. This fact alone may have arrested our own evolution, allowing technology to race ahead instead, a situation we should be wary of propagating. We are watched - whatever is observed is noted. We don't have a singular right to debauchery, nor do we have the authority to condemn other species at the whim of our wills. While most of us would love to be listening, those who would rather not are continuing to corrupt the system. How many of us think that corruption, political or environmental, is a crime against Nature? Does that make a million of us? Or more?