If the mallard wasn't so common, we would probably see it as one of our more handsome of ducks. The drake, as shown in the photograph, is resplendent in breeding colors.
But have you wondered where all of the drakes go during mid-summer? They actually are still around, but have molted into an eclipse plumage, which looks very much like the female's plumage. By fall, they have molted back into their non-eclipse plummage.
These ducks feed almost exclusively on plant matter, but at times they will also eat aquatic vertebrates. They are often seen "tipping up," in the manner of all puddle ducks, with their tails in the air and their bills scouring the bottoms of shallow ponds looking for food. They may also root through fallen leaves on the edges of forests looking for seeds and other foods.
Females select upland nesting sites, often in suburban landscaping. The male does not help with incubation and he guards the female only until she begins to incubate (mostly to prevent other males from mating with her). Once incubation begins, the drake leaves the female for the life of a bachelor.
The traditional “quack” that we think of as the stereotypical duck call is only made by the female mallard; males make a short whistle call and a nasal snort.
Ducks swim in freezing water and rest on ice during the coldest of winter days and one would think that they would lose all of their body heat through their big webbed feet. Fortunately, they seem to tolerate cold feet very well. But losing body heat is a problem. To conserve heat, the arteries and veins in a duck's legs lay next to each other. Warm arterial blood flowing to the foot gives up its heat to the cold veinal blood flowing back to the body. The feet stay cold, but the body stays warm no matter how cold the temperature.
Mallard (Anas platyrhynchos)
Key ID Features: Male has largely tan/brown body with a brilliant, iridescent green head, rusty breast, and black tail. Female is uniformly brown with streaks. Male during eclipse resembles the female.
Present in Park: Year round.
Habitat: Ponds and shallow lakes, but can be seen in larger rivers in open water, especially in winter.
Did You Know?
At Lake Itasca, the elevation of the Mississippi River is 1,475 feet above sea level. It drops to sea level at the Gulf of Mexico. More than half of that drop occurs within the state of Minnesota.