There are two major types of ducks - puddle ducks and diving ducks.
Puddle ducks prefer fresh shallow marshes and rivers. They feed by dabbling or tipping up, and take off from the water by springing into the air and climbing fast. They often have a brightly colored "speculum" or wing patch and because of the placement of their legs and feet, located farther forward, they can walk well on land.
The greenhead mallard is a puddle duck, and it is the most common and most recognizable duck in North America. The drakes have a shiny green head and the females are drab in color.
The black duck is a puddle duck; it is considered by many to be a sub-species of the mallard. It is a large duck, weighing a couple of pounds. It has a dark brown body with a light brown head. Due to low population numbers, the daily bag limit of black ducks has been no more than one for many years.
Source: FWC Hunter Education Program