Diving ducks tend to live in deeper bodies of water than dabbling ducks, and quite a few species, known as sea ducks, actually live in salt water. Diving ducks exhibit more diving behavior than other types of ducks.
Species of diving ducks include:
Ruddy duck (Oxyura jamaicensis)
Ruddy ducks are stiff-tailed ducks, a subgroup of diving ducks with tails that stick straight up in the air at rest. During the mating season, male ruddy ducks develop a bright blue beak.
Mergansers
Mergansers are fish-eating ducks. The common merganser (Mergus merganser), known as the Goosander in England, lives in freshwater lakes and is, as its name suggests, the most common species of merganser.
The red-breasted merganser (Mergus serrator) looks like the common merganser, but it has different nesting habits, preferring more northern salt water over fresh water and nests in the ground (rather than in cavities).
The hooded merganser (Lophodytes cucullatus) is the smallest and rarest merganser. Like the common merganser, the hooded merganser nests in cavities around ponds and swamps.
Harlequin duck (Histrionicus histrionicus)
The harlequin duck gets its name from the distinctive white pattern on the male’s gray feathers. (Females have brown feathers.)
Harlequin ducks are strong swimmers and seem to prefer rougher rivers and coasts.
