Diving Ducks

Arizona’s “diving ducks” form a distinct assemblage of waterfowl that forage by plunging beneath the surface for mollusks, aquatic insects, and vegetation. In Arizona they occur primarily during winter and migration on lakes, reservoirs, rivers, and wetland basins from low desert impoundments up into montane meadows. 

Below is an overview of the diving‐duck assemblage recorded in Arizona. These species span several tribes of Anatidae—Aythyini (pochards & scaups), Bucephalini (bufflehead & goldeneyes), Merganettini (mergansers), and Oxyurini (stiff-tailed ducks)—and include both regular winter visitors and occasional vagrants.

• Canvasback (Aythya valisineria)
  The largest North American diving duck, nesting in Arizona’s marshes and also a winter visitor on large lakes and reservoirs. It has a distinctive wedge-shaped head, red eye, chestnut head, black breast, and white body (Wikipedia, Wikipedia).

• Redhead (Aythya americana)
  A common winter visitor to marshes and reservoirs (e.g., Alamo Lake SP), with males sporting a rounded rufous head and gray body; females are warm brown (Wikipedia).

• Ring-necked Duck (Aythya collaris)
  Perhaps the most numerous diving duck in winter, found on vegetated ponds and reservoirs; males have peaked heads, glossy black backs, and subtle neck rings (Wikipedia, Audubon).

• Lesser Scaup (Aythya affinis)
  One of Arizona’s most abundant winter divers, recognizable by its purple-tinged head and finely vermiculated gray sides (Wikipedia).

• Greater Scaup (Aythya marila)
  Less common than Lesser Scaup, winters on larger, deeper lakes; males have a rounder head and more extensive white sides (Wikipedia).

• Bufflehead (Bucephala albeola)
  The tiniest diving duck, wintering widely on lakes and ponds; males flash a large white head patch, females are gray with cheek patches (Birdwatching Central, Wikipedia).

• Common Goldeneye (Bucephala clangula)
  An uncommon winter visitor to deep rivers and lakes; males show greenish-black heads with white cheek spots (Birdwatching Central).

• Barrow’s Goldeneye (Bucephala islandica)
  A rare visitor, with only scattered records from northern Arizona.

• Common Merganser (Mergus merganser)
  A large, fish-eating duck wintering on rivers and reservoirs; males have iridescent green heads and white bodies (Avibirds.com).

• Hooded Merganser (Lophodytes cucullatus)
  North America’s smallest merganser, found on wooded ponds November–March; male’s dramatic crest is raised in courtship displays (birderfrommaricopa.com).

• Red-breasted Merganser (Mergus serrator)
  An irregular winter visitor to open waters; slim profile with serrated bill and spiky crest.

• • Surf Scoter (Melanitta perspicillata), White-winged Scoter (M. deglandi), Black Scoter (M. americana)
    All are rare winter vagrants in Arizona, occurring most often on large reservoirs or along the Lower Colorado River (Wikipedia).

    Ruddy Duck (Oxyura jamaicensis)
    A compact, long-tailed diver common in winter and breeding in dense marshes; drakes in breeding plumage show bright chestnut bodies and sky-blue bills (Avibirds.com)

  Together, these species illustrate Arizona’s rich assemblage of diving ducks, from locally nesting Canvasbacks to wintering scaups, mergansers, buffleheads, and the distinctive Ruddy Duck.