We were watching peacocks mate last October (which is spring here). As a science freak I could see that the larger and more brightly colored males get more mating opportunities from their much more drab looking female companions.
So the males outlandish plumage is caused by hormones and is naturally selected over a million years or so.
All it really takes to turn on a peacock hen is a big purple chest and a lot of very ornate plumage.
Good on you Lyle for displaying a male peacock in this way. BTW the outstretched tail feathers is known as a 'display'. All of the natural world evolved in parallel with humans and we can easily use them to teach us about reality. Evolution even evolved our belief systems which I find incredible. I suspect it's possible to pray to evolution which seems to tick all of the boxes and then some. At least it's 100% verifiable which helps ease a person out of a world of illusion IMHO.