I'll try to eliminate your confusion. The female is absent because she is sitting on eggs in a pouch-like nest, probably high in a tree very near you. All orioles stop eating oranges for some unknown reason, after the nesting seasons starts, but they should continue to feed from the nectar feeder into September. I believe that your nectar is not right. Do as millions of others do: make your own. Mix one part sugar to four parts warm water, cool and serve. No coloring is necessary. Good luck.