At the time these photos were taken (over a two day period) I observed two separate mothers raising chicks, one with four little ones, and the other with ten.
It's got to be one of the cutest things in nature, imo, seeing little ones riding on the backs of adults!
From what I've seen so far, it would seem that the male doesn't have any part in the raising of the chicks.

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 15th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 15th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 15th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 15th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 15th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chick, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chick, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chick, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chicks, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chicks, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chicks, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chicks, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser chicks, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th

Common Merganser family, Marshall Springs ponds - Fish Creek Prov. Park, Calgary, AB - June 16th