Mallards normally raise one brood a year, but if a skunk, crow, raccoon, opossum or other predator destroys her first clutch, a hen may try again. Nests are also lost to plowing, hayfield mowing and flooding. In addition to the predators mentioned above, snakes, foxes, largemouth bass, muskellunge and snapping turtles also take ducklings. The young can fly after 7-8 weeks. This replacing of feathers demands considerable energy, and the birds seek out food-rich areas.
Hens undergo a similar molt after their ducklings mature.
The wing feathers grow back in 2-3 weeks. In fall and winter, mallards fly south when ice and snow cover their feeding and resting areas. Among puddle ducks, the mallard and the closely-related black duck are the latest fall migrants, often remaining as far north as open water prevails. Many of the mallards found here in the fall are from breeding grounds in Ontario, Quebec and the Lake States. The mallard is one of the earliest ducks to return north in the spring.