Above are two pics of the same couple.  They're Common Mergansers.  We see them every Spring and Fall.  Just passing through - traveling North now and in the Fall will be traveling South.  The female has the reddish colored head and looks like she has a spiked hairdo and a white throat.  The male looks much like the male Mallard Duck except that he is white in the body.  They both have thin, red bills.  They don't feed by dabbling or upending - putting their heads into the water with their tails sticking up in the air - like Mallards and the white ducks on the Lake.  Instead, they feed by diving into the water and swimming underwater looking for fish to eat.  They're referred to as diving ducks as opposed to the Mallards which are called dabbling ducks - based on how they feed.