Platypus (Ornithorhynchus anatinus) Fact Sheet: Diet & Feeding

General

(Grant 2015; Thomas et al. 2017)

• Generalist carnivore
• Typically opportunistic feeders
• Diet appears to be influenced by seasonal prey availability, nutritional factors, and prey behavior

Common prey

(Grant 2015; Marchant and Grant 2015, and as noted)

• Seasonally abundant, bottom-dwelling invertebrates
• Mainly feed on aquatic, bottom-dwelling larvae and nymphs of insects
  • Caddisflies (Trichoptera)
  • Mayflies (Ephemeroptera)
  • Dragonflies (Odonata)
  • Stoneflies (Plecoptera)
  • Flies, mosquitos, gnats, midges (Diptera) (Klamt et al. 2016)
• Freshwater crustaceans
  • Shrimp
  • Crayfish
• Swimming invertebrates
  • Water beetles (Coleoptera)
  • Aquatic insects (Hemiptera)

Occasional prey

(Grant 2015, and as noted)

• Tadpoles
• Small fish
• Aquatic snails
• Small clams
• Worms

Habitat use

• Forage in slow-moving pools and faster-moving areas of streams (Faragher et al. 1979; Grant 2015)
• Preferred habitat
  • Stream edges, pools, and deeper water (McLachlan-Troup et al. 2010)
  • Coarse substrates, such as cobblestones and gravel (Grant 2015)
• May forage in a single pool/stream or travel long distances in a day (Grant 2015)
  • Females: range a few hundred meters to 4 km (2-3 mi)
  • Males: range up to 10 km (6 mi)
• May forage in the same area over several days (Kruuk 1993)
• Exert strong and subtle ecological effects in aquatic food webs (McLachlan‑Troup et al. 2020)
  • Suppress steam invertebrate prey abudance

Activity

• Often forage 10 to 12 hours per day (Grant 2015)
  • Up to 16 hours during winter in Tasmania (Otley et al. 2000)
• May forage continuously for 24 hours or longer (Grant 2007)
  • Bouts of up to 30 hours reported
• Also see Diving

Finding food

• Swim along the bottom of streams and lakes, probing substrate with bill (Grant 2015)
  • Move bill through substrate from side to side (Scheich et al. 1986)
  • Appear to use mechano- and electroreception to find prey and to navigate
    • Also see “Senses of the bill” in Senses
• Chew/grind and swallow food at the water’s surface before next dive (Grant 2015)
  • Also see “Head, bill, mouth” in General Appearance
• Also see “Juvenile” in Life Stages

Nutrition, digestion, and scat

• Food requirements (Holland and Jackson 2002; Grant 2007)
  • High but variable
    • Said to need to consume 13-28% of body weight each day, up to 100% or more in lactating females
• Nutrition
  • See Thomas et al. (2017), Table 4, for nutritional profiles of prey items
• Digestive system (Grant 2007)
  • Simple structure
    • Stomach small
    • Intestines short
• Scat (Grant 2007)
  • Description
    • Black
    • Semi-solid
    • Foul-smelling
  • Prey items cannot be visually identified from scat (Thomas et al. 2017)
    • Platypuses grind invertebrates in bill—swallow soft-bodied parts and spit out chitinous exoskeletons typically used in prey identification

Platypuses commonly feed on aquatic insect larvae and nymphs, and bottom-dwelling crustaceans, like this crayfish.

Platypuses have high energy (food) requirements. They typically forage for 10 to 12 hours each day—even longer under colder conditions. Females producing milk for their young have very high energy needs and can consume 100% or more of their body weight in a day.

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

Image location: Taronga Zoo, Sydney

Some platypus prey are surprisingly small.

Platypuses can hold many tiny prey in their cheek pouches while diving. These prey are then chewed and swallowed at the water's surface before the next dive.

All this diving takes a lot of energy. Imagine making 75 dives per hour for 10 to 12 hours a night!

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