I found these Mallards (a male and female) swimming in this alien-looking and desolate pondscape on a warm afternoon in December.
This is odd scene is actually a Beaver pond in decline. Several months ago the city removed the Beavers and breached their dam. Since then the water level has fallen significantly. The clumps of brown vegetation you see are actually the remnants of reed beds that the Beavers cut back in order to clear the pond and to use as material for their dam. The cut reed stalks are draped with dried clumps of algae that collected as the water retreated.
Even though the Beavers are gone and the water level is lower, this pond still attracts is fair share of urban wildlife. These Mallards were just one of the many species of ducks sharing the water on that day.