I have lived for the last 3 years in a semi-rural area on the outskirts of Elgin, Illinois. The only species of hummingbird here is the Ruby-throated. I have a sugar-water feeder about 15-20 feet from my windows that is visited multiple times every day by hummers. Sometimes two at a time. I often admire the emerald color on the back in sunlight. However, I have NEVER seen the red throat. I have looked in sunlight and in shade. I have looked with binoculars. I have looked as the bird turns it's head in different directions. I have looked as the bird is hovering, and as it is sitting. The throats always look white. I hear that the red looks dark in certain light. But these always look white, never dark. I hear only the mature males show the red, not the females or immature males. But in 3 years of closely watching hummers at my feeders daily (and at flowers), you would think I would see the red at least once.