Distinguishing Characteristics

Breeding male Hooded Merganser with crest lowered, Iroquois NWR, NY

Adult female Hooded Merganser, NY, May

Non-breeding adult male Hooded Merganser

Smallest North American merganser. Total length: males 43–49 cm; females 40–46 cm. Identified as a merganser by long, narrow, serrated bill. Adult sexes dimorphic most of the year. Male easily distinguished from all species by small size, flashy white, fan-shaped crest bordered by black, and buffy sides with black and white vertical stripes. When crest is depressed, a white line extends back from the eye. Female distinguished from other mergansers by small size, non-red bill, and bushy, grayish-brown crest. Immature male resembles adult female but lacks its distinctive crest; also, bill darker, and some black feathers present on the head. Adult male in Basic plumage resembles female except for yellow iris and darker bill. Female iris brownish.

At a distance in flight, Hooded Merganser can be mistaken for Wood Duck (Aix sponsa). Both species have large tails and appear dark above and light below, although the merganser is less erratic, more rapid, and appears more streamlined than the Wood Duck. Upon closer inspection, Hooded Mergansers can be identified by their slender body and head, black and white coloration on narrow, almost triangular wings, and rapid, shallow wing beat.