Mother Starling (Bird) abandoned babies in the nest...what to do?

I went to my pool shed yesterday, to retrieve a pitcher that I commonly use for watering. I haven't used it since last summer. When I pulled it out, there was a nest with babies in it (not eggs..babies). I've been watching it carefully, from afar, since, and notice that the mother has not returned. I do not want the babies to starve...what do I do?