So I closed all the windows, and I couldn't hear the birds at all!
I listened real hard, and there was no bird noises. I listened real hard, still no bird noises. I thought I was imagining the bird noises being gone, but I really couldn't hear them!
My previous residence had windows that I thought were great at cutting down noise, but they sure didn't work as well as the windows I've got now.
This is excellent news for my habit of sleeping in until 8:30-9 AM.