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Freckled Duck (Stictonetta naevosa) Fact Sheet: Physical Characteristics

Physical Characteristics

Body measurements

Attribute Males Females
Weight 747-1130 g (1.65-2.49 lb) 691-985 g (1.52-2.17 lb)
Head-body length 500-560 mm (20-22 in)
Average Wing Length 234 mm (9.21 in) 222 mm (8.74 in)
Wingspan 770-820 mm (30-32 in)


Data sources:

  • Frith (1967): weight, head–body length
  • Norman (1982): average wing length (sample from Victoria)
  • Marchant and Higgins (1990): wing span

General Appearance


  • Mostly dark gray-brown with small buff-to-whitish “freckles” on head and upperparts (Johnsgard 2010; Carboneras and Kirwan 2018, except as noted)
    • From a distance, appear almost black
    • Distinctive coppery sheen in flight (Pizzey and Knight 2012)
    • Underparts paler
      • White, triangular patch and whitish speckling (Pizzey and Knight 2012; Carboneras and Kirwan 2018)
    • Pattern of irregular lines on flanks and at base of tail (“vermiculation”)
    • Undertail buff to warm brown
  • Male and female difficult to tell apart at a distance (Frith 1965)
    • Female’s plumage lighter and lower contrast compared to male (Frith 1965; Frith 1967; Carboneras and Kirwan 2018)
      • Freckles buff, not pure white
      • Head and neck coloration not as dark
  • Juvenile (Frith 1967; Johnsgard 2010)
    • Resembles female, except more pale
    • Freckles fine and a deep buff color
  • Molting
    • No eclipse plumage (Carboneras and Kirwan 2018)
    • Body feathers molted continuously (Marchant and Higgins 1990)
      • Peak in late summer and early winter
    • Wing feathers often molted late summer (after breeding) (Marchant and Higgins 1990)
      • May occur in spring in some individuals

Head and bill

  • Head appears almost triangular in side profile due to slight crest (Johnsgard 2010)
    • Distinctive trait
  • Eye
    • Iris brown (Carboneras and Kirwan 2018)
  • Bill
    • Coloration
    • Shape
      • Curved or “dished” appearance (Frith 1967)
        • High at base (Frith 1967)
        • Tip appears flattened (Johnsgard 2010)
        • Large nail on tip (Johnsgard 2010)


  • Coloration
    • Dull slate-gray (Carboneras and Kirwan 2018)

Sexual Dimorphism

Size of head

  • Longer in adult male (Carboneras and Kirwan 2018)


Trachea (windpipe)

  • Elongated in adult male (Frith 1967; Fitch 1999)
    • Forms coil outside sternum region
    • May amplify male’s vocalizations when visual communication is impeded (Fitch 1999)
      • At night
      • When line of sight blocked by tall, dense vegetation near nest
    • For early studies, see Campbell (1899) and Johnsgard (1961)
  • Comparison to other birds
    • Elongated trachea present in at least six avian orders and 60 species (Fitch 1999)
    • Long, looped windpipes also found in some swans (e.g., Trumpeter Swan), cranes, and the Magpie Goose (Anseranas semipalmata) (Frith 1967; Gaunt et al. 1987; Fitch 1999)


Similar-looking ducks

(Carboneras and Kirwan 2018, except as noted)



  • Fact sheet with illustrations (Game Management Authority of Victoria)
  • Video (Game Management Authority of Victoria)
    • 5-minute video with description of Freckled Duck and comparisons to similar ducks

Telling the Sexes Apart

Female Freckled Duck

Male Freckled Duck with red bill base

Top image: A female Freckled Duck.

Bottom image: A male Freckled Duck with red bill typical during breeding season.

Image credits: © San Diego Zoo Wildlife Alliance. All rights reserved.

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