Equal tempered birds, whoever heard of it?
Why conform to a set scale when your listeners are accustomed to the full frequency spectrum and can get what you are saying without such constraints on your vocabulary such as set tonal values.
Birds can harmonize with and mimic other sounds they don't need no steenking Melodyne.
I have the most humble of Starlings that lives on next doors' roof, he can mimic a dozen or so different types of birds at least so as you cant tell the difference between him and the original subject he's copying. So he can certainly accurately pitch himself exactly where he wants if he is so inclined.
I think the only reason that birds don't win many grammy's is because they have more of a jazz sensibility and have a different agenda than pleasing the masses. Besides if you can sing well enough to pull another bird then what else is there to be done?
More interesting would be to use Melodyne to learn to derive the scales the birds are using, the way round you've got it is like saying birds don't fly as good as planes and they could use a little tuning in that area because we've been flying for over 100 years now so we're the experts...