Freckled Duck (Stictonetta naevosa) Fact Sheet: Diet & Feeding

Algae and plant matter thought to be prominent

(Frith et al. 1969; Carboneras and Kirwan 2018, except as noted)

• Algae (e.g., Chara, Nitella)
• Green parts of aquatic plants (e.g., hornwort, coon’s tail)
• Seeds
• Grasses that grow above water (e.g., Typha)
  • Infrequently, dry-land grasses

Animal diet items

• Aquatic insects and their larvae (Frith 1965; Frith et al. 1969; Marchant and Higgins 1990)
• Zooplankton (Crome 1985)
• Diet may have a higher proportion of crustaceans in locations where aquatic plants and algae are not abundant (Briggs 1982)

Research note: Studies investigating diet composition using only gizzard contents have characterized Freckled Duck as being “mainly herbivorous,” but Briggs (1982)—who reported on gizzard as well as esophagus contents—indicates that examining only gizzard contents may underestimate the amount/presence of invertebrates. Frith et al. (1969) also suggest this. Research across a range of geographic and seasonal conditions may be needed to confirm diet composition.

Adaptations for filter feeding

• Ridges (lamellae) and grooves on each side of upper bill (Crome 1985)

Finding food

• Freckled Ducks wade in shallow water and filter-feed near bottom (Frith 1965; Frith 1967; Johnsgard 2010; Carboneras and Kirwan 2018)
  • Move head from side-to-side (Marchant and Higgins 1990)
  • Feed just above muddy bottom, not in mud (Frith 1967)
• Less often, nibble on water’s surface while swimming slowly (Frith 1965; Frith 1967)
• Immerse bill or upend in shallow water (Frith 1965; Frith 1967; Lowe and Lowe 1974; Johnsgard 2010; Carboneras and Kirwan 2018)
• Seek out areas where algae grows [observed in managed care] (Frith 1967)
• Stretch and jump to strip seeds from grass heads (Lowe and Lowe 1974; Marchant and Higgins 1990)
• Also see Activity Cycle

Freckled Ducks most often wade and feed in very shallow water—but sometimes they upend in deeper areas.

Freckled Ducks feed just above the bottom, not in the mud.

Image credit: © Ed Dunens via Flickr. CC by 2.0; some rights reserved.

Image location: Lake Wendouree, Victoria, Australia