Pied-billed Grebe:

Diving duck, almost never on land, smaller than mallard, light grey short conical bill with black ring on it, white undertail coverts, chunky bird with short beak and big head

Call: like a howler monkey, ascending howls, cow cow cow

Red-necked Grebe:

Largest grebe, ~size of mallard, long red neck, plain colored body, white cheek patch, black cap, long yellow beak

Horned Grebe:

size of Pied-billed Grebe, red neck, head is overall black with two yellow horns extending from eyes, bodies seem tailless, red flanks, red cheek dot

Eared Grebe:

Same as Horned Grebe but black neck, black top, black head, yellow fanning ears instead of horns, black crest

Mute Swan:

introduced from Europe, larger than ducks, plain white, neck is in an "S" shape, have orange beaks with black base

Tundra Swan:

Smaller than mute swan, black beak, all white, neck straightened to candy-cane shape

Gadwall:

Tail points up, very black butt, may see white spot just above black butt

American Widgeon:

Beak is bluish grey with black tip, white crown and dark green patch behind eye (iridescent), rusty colored body, black undertail coverts, white spot just in front of coverts

American Black Duck:

Looks like female Mallard but this has overall dark color, bright yellow beak with black tip, black eye stripe, blue/iridescent speculum with no border, often associates with Mallard

Mallard:

 M:  bright green head with white stripe underneath, tail curls up, dark top, grey lower, black butt with white feathers in the middle, blue speculum with white border

F: orange beak with black saddle, very contrasty with breast darker, black eye stripe, blue speculum with white border, curled tail feathers

Call: persistant quack

Canvasback:

a little larger than Mallard, black tail coverts and butt, white body, black breast, dark red/copper neck and head, black beak that gently slopes (doesn't have an angle)

Redhead:

Very similar to Canvasback, black butt, grey body, black breast, red neck and head BUT: grey beak with black tip and more angle from head to beak (normal duck beak), body is darker grey

Ring-necked Duck:

Dark overall, black back and grey flanks, white line above mid-dorsal region, tri-colored beak (base is dark grey, white ring, black tip), feather crest on head

Greater Scaup:

Grey back, black chest, black butt, grey flanks, bluish grey beak with tiney black tip, black/green iridescent head

Lesser Scaup:

Similar to Greater Scaup - grey back, black head, black chest, black butt, grey flanks, bluish grey beak with tiney black tip; BUT has crested head, black/purple iridescent head

Bufflehead:

Bottom half white, black top, black/iridescent head, big white circle extending behind eye with no black border

Hooded Merganser:

M: white patch extending from the eyes that is bordered by black line, crest, tail pointed up, very slender beak with serrations, chesnut flank

F: has crest on head but not white patch, red/brownish head and body, upperbill darker than lower, smallest of the Mergansers (~bufflehead)

Red-breasted Merganser:

M: medium size, red beak, black head, white ring around neck, shaggy/hairy (oldman) crest, breast rufious color, grey flanks, black top on back with white inbetween that and the grey

F: grey portion on front of neck, hairy (oldman) crest, rufious color around head, white/grey body

Common Merganser:

F: red beak, rufious head, crest, sharp line where rest of body turns white/grey

M: red beak, black head, black top of back, whiter underside