Duck, Duck, Mallard

This little pair of mallard ducks has been visiting our front yard for several weeks now. They discovered the bird seed buffet that falls to the ground from the feeder in the tree above. We really enjoy having them, but I worry about them hanging out in such an urban setting with all the dangers of dogs, cats, and cars.

I could, however, do without the Saturday morning 6:26 am wake up call I got today. Only the female was in the yard and she was quacking incessantly; our bedroom window is about 15 feet from the tree and feeder. I assume she was calling for her mate as he wasn't around. Should I be concerned?