You just can't see the forest through the trees, can you? Blue winged and gold winged warblers are obviously variations of the same species. Is that so hard to understand?
Apparently it is for the American ornithological community, which has disagreed with you for well over 100 years. Let me remind you. I took exception to the statement 'Biology is biology regardless of evolution.' The two warblers I mentioned were classed as different species before Darwin even came along. They've continued to be classed as different species. You are proposing they are the same species, simply because their being different species causes difficulties for your anti-evolution position. Thus biology isn't biology regardless of evolution. If you're anti-evolution, that causes you to merge what are considered distinct species.