Birds of the World






Totipalmate Swm



 NW Vultures







   NW Flycatchers


 Aust. Wrens
 Aust. Robins
 OW Orioles
 OW Flycatchers
 N Creepers
 OW Warblers
 OW Sparrows
 9-prim. Oscines

   Hawaiian Honycrp
   NW Sparrows
   NW Warblers
   NW Blackbirds



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Screamers, Magpie-Goose, Whistling Ducks, White-backed Ducks
Ducks, Geese, and Swans
   Geese and Swans, Freckled Duck, Shelducks
   True Ducks
      Perching Ducks, Dabblers, Bay Ducks (Pochards), Sea Ducks, Stiff-tailed Ducks
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All species of swans, Postnuptial molt in ducks
White-chinned Pintail
Tundra Swan, Canada Goose, Mallard, Fulvous Whistling-Duck, Canada Goose, Snow Goose, Common Shelduck, American Wigeon, Wood Duck, Blue-winged Teal, Mallards (dabbling), Canvasbacks, Red-breasted Merganser, Ruddy Duck
Chinese (domestic) Goose - "Jake", Canada Goose, Whooper Swan, Black Swan,
Common Shelduck
, Australian Shelduck, Pacific Black Duck, American Wigeon,
Northern Shoveler
, Mallard
  Family Anatidae - Ducks, Geese, and Swans
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  148 species, 38 genera (157, 40 if the previous two groups are included) Sibley and Monroe (1990). 158 species, 49 genera. Dickinson (2003) and Harris (2009). 159 species, Clements (2007). Worldwide. Many breed in northern areas where days are long during the breeding period. They are strong fliers and many are migratory
   Members of this group may be called waterfowl. There are two major groups - the geese and swans, and ducks. In many species, males are larger than females (sexual dimorphism). Many ducks are also dichromic (males are brighter than females). Anseriforms are medium to large birds. Larger swans are among the heaviest flying birds. In all, the bill is covered by a thin skin with a terminal "nail" and is lamellate (finely serrated or grooved on the edge). The fleshy tongue is bordered with spiny processes. Pelvic muscles are ABX+, the biceps slip is present and flexor tendons are Type 2. The uncinate process is present. The three front toes are fully webbed (palmate) and the hallux is small or set higher than the other toes. Males have a modified cloacal wall that forms a functional penis (in most birds, sperm are transferred by cloacal apposition rather than actual intromission). They have unfeathered areas (apteria) between their contour feather tracts. Flight feathers are molted simultaneously giving rise to a flightless stage with its "eclipse" or basic plumage. During the rest of the year they wear their alternate (nuptial) plumage.  Most male ducks have a bony tracheal bulla that may be involved in sound amplification. They have 16-25 cervical vertebrae.
   Most species are aquatic in summer but some swans and geese become terrestrial grazers in winter. Most are gregarious, some forming enormous rafts of the same or mixed species. Most are opportunistic feeders. Many ducks sift mud for plankton or larger food. The Northern Shoveler, Anas clypeata, filters plankton form the surface, often feeding in large groups. Others (dabblers) immerse their head and tip their body to reach submerged vegetation. Diving ducks use their feet to submerge to find vegetation, insect larvae, molluscs, crustaceans, and fish. Perching ducks forage on the forest floor eating seeds and nuts.
     Many species undergo spectacular migrations to and from far northern breeding areas to more tropical wintering regions. One, the Garganey (A. querquedula) is a trans-equatorial migrant. Some species undertake molt migrations to arrive at rich sources of food before they loose their feathers and become flightless. Migration is often nocturnal but many fly during the day along the coast. The Bar-headed Goose (Anser indicus) migrates over the Himalayas. Geese may average 60 mph during migration   Swans and geese are monogamous and tend to mate for life. In ducks, pair formation often occurs on the winter ground and males follow females returning to her natal breeding area. They have a variety of courtship displays that we can see in winter. Many ducks are monogamous. However, polygyny and even brood parasitism are strategies found in some species.
    Most waterfowl build nests on the ground, often close to water (one species nests in burrows, several are hole nesters). Young are precocial. Adults may care for chicks in geese and swans but male ducks usually desert the nest early in incubation and begin their complete molt. The female is left to care for the young. Broods vary from 5-6 in swans to 12 or more in ducks. Young leave the nest within a day of hatching and follow their mother as they learn to feed. Some young form crèches. Fledging takes at least 6 seeks in most.
   Waterfowl have given rise to a variety of domesticated species in various regions of the world.
Canada Geese
Canada Geese, Branta canadensis,
with young. Middleton Place                                               SI Web Link
  Sibley and Ahlquist (1990) group the remaining waterfowl as follows:

   Infraorder Anserides
      Subfamily Oxyurinae - Stiff-tailed Ducks - small ducks with their feet set well back (e.g., Ruddy Duck). [8 species, 2 genera]
      Subfamily Stictonettinae
        Freckled Duck - large dark duck with fine white speckles; large head and peaked crown - sw Australia. 1 species, 1 genus - see below.
               Differences from other anatids verified by DNA comparisons. It has been suggested that the species was part of an ancient Gondwanan
               radiation that occurred before true ducks evolved.
      Subfamily Anserinae: 
        Geese - large-bodied birds of high latitudes; necks shorter than the body (e.g. Canada Goose). 43 species, 14 genera. 
        Swans - large, long-necked birds (e.g., Tundra Swan) 7 species, 2 genera.
      Subfamily Tadorninae:
        Shelducks - intermediate between geese and ducks - not found in North America. 7 species, 2 genera.
      Subfamily Anatinae: 82 species, 22 genera
         Perching Ducks - forest ducks that may perch in trees (e.g., Wood Duck) 
         Dabbling Ducks - fresh-water ducks with a simple hind toe (feed from the surface) (e.g., Mallard)
         Pochards (Bay Ducks) - heavy-bodied bay ducks (e.g., Lesser Scaup)  
         Sea Ducks - swimmers and divers, bill with serrated edges - often found in salt water (e.g. Red-breasted Merganser)     

    They list 161 species in 48 genera in the order,

   Clements (2007) lists two families - the screamers  (Anhimidae) and waterfowl (Anatidae).  He begins the Family Anatidae with the Magpie Goose, then lists the Whistling-Ducks, followed by swans, geese, shelducks and their relatives, steamerducks, perching ducks, dabbling ducks, pochards, and sea ducks. He includes  Stictonetta (Freckled Duck) within the geese. He lists 162 species in this order. Dickinson (2003) and Harris (2009) also include the Magpie Goose in the Family Anatidae, listing 158 species, 49 genera.
  Subfamily Anserinae - Geese and Swans
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  (Subfamily Cygninae - Swans)
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  43 species,14 genera (Geese); 7 species, 2 genera (swans). Worldwide.
   Geese and Swans are large waterfowl. They are monomorphic (sexes look alike) and maintain a long-term pair bond (sometimes for life). They breed on the northern tundra. Young may remain with their parents for extended periods - through the migration and into winter.
   The AOU Checklist includes both groups in the subfamily Anserinae...
   True geese include members of the genera
      Anser - Grey Geese (domestic goose, Swan Goose);
      Chen - White Geese
      Branta - Black Geese (Canada Goose)
   The Cape Bareen Goose (Cereopsis) and New Zealand Geese (Cnemiornis - now extinct) may belong to the shelducks or form their own subfamily. The Coscorba Swan is probably the closest living relative of true geese.
   Swans are the largest waterfowl. They are largely herbivorous. They feed in water by dabbling and are often seen grazing on land. They are monogamous. They lay 4-7 eggs. Incubation lasts 34-45 days. Along with Whistling-ducks,swans are the only waterfowl in which males assist with incubation. Species are listed below:
Snow Goose
"Blue" and Snow Geese, Chen caerulescens (with Canada Geese), Oak Openings, OH                                           SI Web Link
All swans:

   Mute Swan, Cygnus olor.
Palearctic. to India and se China in winter.
   Black Swan, Cygnus atratus. Australia and Tasmania; introduced to New Zealand.
   Black-necked Swan, Cygnus melanocoryphus. Southern Brazil to Tierra del Fuego and the Falkands
   Trumpeter Swan, Cygnus buccinator. Western North America.
   Whooper Swan, Cygnus cygnus. Palearctic. Winters to India and se China.
   Tundra (Whistling) Swan, Cygnus columbianus. Kola Peninsula to arctic northern Siberia, wintering in western Europe to southern Asia. Arctic
      tundra on North America, wintering in western and coastal eastern US.
   Coscorba Swan, Coscorba coscorba. Southern Brazil to Paraguay, Uruguay, Tierra del Fuego and Falkland Islands. This is the smallest
      swan. It is white except for black tips on the outer primaries. It has a red beak, legs and feet.  
  Subfamily Stictonettinae - Freckled Duck
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  1 species, 1 genus (Stictonetta naevosa). Southern Australia.
   A large duck with off-white speckles and a large head with a peaked crown. It dabbles in shallow water, preferring swamps. In flight, it has a distinctive wing-beat. In dry years, it moves to coastal regions. Part of a Gondwanan radiation before true ducks appeared?
  Subfamily Tadorninae - Shelducks
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  8 species, 2 genera (Tadorna, Alopochen). Basically Old World waterfowl. 
   Shelducks (Tadorna) are Old World ducks - intermediate between true geese and ducks. They are large semi-terrestrial waterfowl, intermediate between geese and ducks. They are slightly dichromic. The tertiaries have a green speculum. They feed on small animals (winkles, crabs) and grasses and other plants.
   They form long-lasting pair bonds (Paradise Shelducks, Tadorna variegata, in New Zealand mate for life) and nest in holes (or nest boxes). The AOU Checklist lists only two species in North America, the Comb Duck, Sarkidiornis melanotos, and the Orinoco Goose, Neochen jubata, both accidental in the US.
   The Egyptian Goose, Alopchen aegyptiacus, is often included with the shelducks. They breed in Africa and is abundant in the Nile Valley and south of the Sahara. It has been introduced in several areas in Europe. This species is largely terrestrial. Sexes are alike. They eat leaves, grass, stems, seeds and occasionally small animals. They prefer holes in trees in parklands for their nests.
Ruddy Shelduck
  Common Shelduck, Tadorna tadorna.
Zaanse Schans, Netherlands.
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  Subfamily Anatinae - True Ducks
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  82 species, 22 genera (Sibley and Monroe, 1990).
   Unlike Whistling-Ducks, Geese, and Swans, "true ducks" are sexually dimorphic - males are brighter, often ornate, while  females are cryptically colored. The female alone incubates and cares for the young - the male usually deserts early in incubation. Polygyny is possible and cross-breeding may be more common because the pair bond is brief. True ducks undergo a simultaneous molt of their flight feathers - the male after abandoning the female, the female while she may still be taking care of the young. This molt is an accelerated pre-basic (post-nuptial) molt and produces a dull, "eclipse" plumage - supposedly the basic plumage. Because all feathers are shed and regrown at the same time, this molt may be completed in 2-3 weeks. Birds then undergo a pre-alternate molt that restores the breeding (alternate) plumage before they undergo fall migration.
   Thus, on arriving at the winter grounds, males are wearing their display finery and they begin to court females. Pair-formation occurs on the winter grounds in most species. They male accompanies the female, often to her natal area, where the pair breeds.  
American Wigeon
American Wigeon, Anas americana.
Castalia, OH.
                                  SI Web Link
  Perching Ducks - Tribe Cairinini
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    Perching ducks include the Mandarin Duck, Aix moschata, and Wood Duck (A. sponsa). They are short-legged and long-tailed ducks. They are shy and prefer sheltered water with trees. They nest in cavities (or nest boxes). Wood Ducks are common in cypress swamps in our area.
    Members of this genus are often placed in the "perching ducks," a paraphyletic group intermediate between shelducks and dabblers. It is not clear to which of these groups they are most closely affiliated. Sibley and Monroe, 1990, place them in the Tribe Anatini (our Subfamily Anatinae). They begin the Tribe with the Ringed Teal, Callonetta leucophrys; the Wood and Mandarin Ducks, Aix; the Brazilian Teal, Amozonetta brasiliensis; the Torrent Duck, Merganetta armata; the Blue Duck, Hymenolaimus malacorhynchus; and members of the genus Anas (the dabblers)
Wood Duck

Right. Female Wood Duck, Aix sponsa..
Toledo, OH
 SI Web Link

    Dabbling Ducks - Tribe Anatini
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    Dabbling ducks all belong to the genus Anas (42 species -Sbley and Monroe, 1990). They are cosmopolitan.
   They swim and "dabble," feeding on or near the surface or "upend," tilting their body vertically to feed on deeper aquatic vegetation in fresh water (they don't usually dive beneath the surface). Dabbling ducks are widely distributed around the world.
   There are four species of dabblers on the Seabrook Island list... The Blue-winged Teal, A. discors, is the most likely dabbler to be seen on Seabrook.
   It may be of interest that all dabblers in the genus Anas freely interbreed in captivity and may produce some rather bizarre domestic configurations. Hybrids are also seen in the wild. Some have speculated that the separation of species in this genus is rather arbitrary. However, in the wild various species do form isolated populations with few natural hybrids and probably represent valid species. This is a closely related cluster of ducks.
Palmate foot

Blue-winged Teal

, Anas

  SI Web
Four Mallard males, dabbling.
Pawley's Island.
Mallard, Anas platyrhynchos - palmate feet. Note reduced and elevated hallux (1st toe).
    SI Web Link
    Pochards, Bay Ducks - Tribe Aythyini
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    About 15 species. Cosmopolitan but most are found in the Northern Hemisphere.
   Pochards are heavy-bodied bay ducks. They are generally known as "diving ducks." They are found in coastal areas and are foot-propelled divers - most keep their wings tightly closed against the body under water. Males have simple color patterns and females tend to be evenly colored. They lack the spotting and barring of female dabblers.
   They have thick bills - many feed on bottom-living invertebrates (mollusks). They are strong fliers. Northern species tend to be migratory.
   Members of this group are more commonly seen on fresh water than other diving ducks. They are gregarious. Scaup in particular may form large rafts of foraging ducks in bays and offshore in winter. However, in our area, pochards are more common in impoundments such those as Huntington Beach and Bear Island. Two pochards (Greater Scaup, Aythya marila, and Lesser Scaup, A. affinis) are included on the Seabrook Island list. Others are regular on Kiawah and probably should be added to our list.


Canvasbacks, Aythya valisneria.Huntington Beach State Park.
                                  SI Web Link
    Sea Ducks - Tribe Mergini
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    About 20 species. Worldwide.
   Sea Ducks are active swimmers and foot-propelled divers. They have well-developed salt glands. Fish-eating members have serrated tomia (edges of the bill) that help them grasp prey. Some feed on molluscs and crustaceans. They propel themselves underwater with their feet (some species also use their wings underwater and dive with a wing flick - these include the scoters and eiders). Hooded Mergansers, Lophodytes cucullatus, are familiar winter companions on Seabrook.
Red-breasted Merganser
Red-breasted Mergansers, Mergus serrator. Lagoon, North Beach (right)
SI Web Link

Bufflehead, Bucephala albeola. Palmetto Lake
                                                                                               SI Web Link

Bufflehead diving
    Stiff-tailed Ducks - Tribe Oxyurini
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    6 species, 1 genus (Oxyura). Freshwater diving ducks.
   Stiff-tailed ducks are small ducks with their feet set well back and a long, spiky tail. They have relatively swollen bills. Their legs are set back on the body so they are awkward on land.
   They are found in fresh and brackish water. Our Ruddy Duck, Oxyura leucocephala,  is the most familiar representative.
Ruddy Duck
Right. Ruddy Duck, Oxyrura jamaicensis.
Monterey Bay Aquarium
 SI Web Link

Post-Nuptial Molt in Ducks

Ducks undergo a post-nuptial (pre-basic) molt into an eclipse plumage. The flight feathers (remiges and rectrices) are lost simultaneously and individuals become flightless for a time on the breeding ground (and are seldom seen because the flilghtless duck is quite wary and remains hidden). This accelerates the molt process from probably 6 weeks to about two. Birds then molt into their breeding (pre-alternate plumage) before fall migration. It is thought that this facilitates pair formation on the winter grounds before spring migration. Pairs migrate together back to the breeding area, often selecting the female's natal area.
    Banner - Canvasbacks. Huntington Beach State Park, SC.