The change is so gradual that it went un-noticed. Even a couple of years ago, I used to see them everyday on our window sill. I didn't change home, but they stopped coming. If not at my window, at least they used to be in our basement parking lot. Now I look carefully, they are gone from there too.
Concern is, they are very used to urbanization. If they can't keep up, we're screwing up really fast.