November 10, 2015 Mammals No Comments

(Ornithorhynchus anatinus)

Juvenile female platypus

Juvenile female platypus, Cold Creek. Image © Tamielle Brunt / Wildlife Queensland

Also known as the duck-billed platypus, boondaburra, mallangong or tambreet (Indigenous terms around Yas, Murrumbidgee and Tumat), or tohunbuck (Goomburra language, Darling Downs).

The platypus belongs to the order Monotremata, meaning ‘one hole’ because it has a single opening for its excretory and reproductive systems. The first white Australian record of a platypus was recorded in 1797; the British Museum still owns the original dried specimen it received in 1799 (which shows scissor marks where the curator attempted to prove the specimen was a hoax).

The platypus occurs only in Australia though similar fossils from 60 million years ago have been found in South America. Platypus populations occur throughout Tasmania, and up the east coast of Victoria, NSW and Queensland as far as Cooktown. The platypus is now extinct in South Australia though Kangaroo Island has a reintroduced population.

The platypus is the only member of the genus Ornithorynchus.


The platypus is one of the most easily identifiable animals in the world.

  • Duck-like bill, broad flat tail and thick waterproof fur
  • Webbed front feet, partially webbed hind feet
  • Deep brown fur on its back and top of head, golden or silky grey underneath
  • No external ear structure
  • Females average around 900g and measure 43cm long; males average 1.7kg and measure 50cm long (average size increases the further south the animal is found)
  • The male has bony spurs on both hind legs for defence. These spurs are connected to a venom-producing gland in the thigh.


  • Concentric rings appear on surface of the water when platypus dive and when they feed on the surface.
  • A trail of bubbles shows their progress underwater.
  • A characteristic ‘bow-wave’ when swimming on the water surface
  • Burrow entrances in banks are typically 10–15cm in diameter. The burrow entrance maybe beneath the water surface or more commonly from 5cm to 1m above the water level and often hidden by overhanging vegetation
  • Well-worn slide mark from the burrow directly into the water.
  • Characteristic footprints sometimes left in the soft mud on the riverbank, especially near a burrow


  • Freshwater streams, lakes or rivers, including artificial dams
  • Alpine to tropical areas


Life history
  • 12 years average life span in the wild
  • 15–over 20 years in captivity.

The platypus (and echidna) are unique mammals because they lay eggs and feed their young through milk-producing spongy glands.

  • Breeding season varies with location: recorded as mating in August in Queensland and October in Tasmania
  • Females first mate aged 2 years, some wait until they are 5.
  • 1 litter in Spring of 1–2 eggs (may not reproduce every year)
  • Incubation period 10–11 days during which the female holds them against her belly with her tail
  • Newborn platypus are around 1.5cm long, are weaned at 4–5 months and remain in the burrow until they reach about 80 per cent of adult weight at about 6 months.
  • Carnivorous diet of fish eggs, worms, insects, crustaceans, molluscs, and tadpoles, plus larvae of caddisflies, mayflies, two-winged flies and shrimps.
  • Feed almost totally in the water and mainly on bottom-dwelling prey.
  • Feed mostly in the early morning and evening
  • Closes its eyes and ears when diving for food but receives information through the bill that navigates and locates prey in the water.
  • The bill contains two types of electroreceptors: one senses touch, the other senses electric currents produced by the muscle contractions of prey.
  • Foraging platypuses stay underwater for up to one minute. All food is eaten on the surface.
  • Males fight over females in the mating season, using their venomous spurs on rear legs as weapons.
  • Territorial and solitary, platypus do not live in social groups. Males are not involved in raising young.
  • Platypus have been known to migrate across paddocks and similar land to reach new home waterways.
Home range
  • Home range is normally 2.5ha but can be up to 15ha.
  • Generally travels up to 1km along a stream but can travel up to 7km.


  • Found in waterways all along the eastern edge of Australia, from Tasmania to the Arran River near Cooktown. Wildlife Queensland research suggests that in Queensland this is not one continuous population, but at least three discontinuous populations.
  • Range does not extend much past the Great Dividing Range in most areas but as far west as western Victoria.


  1. Human impact on habitat and food sources:
    • Waterways are under threat from dam construction, riverbank erosion, irrigation, chemical pollution and garbage.
    • Platypus are vulnerable to being caught in fishnets and traps as well as occasionally on fishing lines baited with worms.
  2. Foxes and cats
  3. Loss of habitat makes isolated populations more vulnerable to decreased genetic diversity.
  4. Climate change causing drought and loss of habitat

Platypus facts

Until the early 20th century the platypus was hunted for its fur: 40 pelts made a cape. The platypus is one of the few venomous mammals, the spur on the hindfoot delivers a poison capable of causing severe pain to humans.

Platypus are big eaters and have been recorded consuming the equivalent of 15–30 per cent of their total body weight in a day.


  • IUCN: Near Threatened (2016 Red List)

More information

  • Augee, M.L. (ed) (1992). Platypus and echidnas. Royal Zoological Society of New South Wales. Mosman, New South Wales.
  • Carrick, F.N (1995). Platypus Ornithorhynchus anatinus in Strahan, R (ed) Mammals of Australia. Reed Book/Australian Museum, Sydney.
  • Evans, B.K., Jones, D.R., Baldwin, J. and Gabbot, G.R.J. (1994). Diving ability of the platypus.Australian Journal of Zoology. 42: 17-27.
  • Fenner, P.J., Wiliamson, J.A. and Myer, D. (1992). Platypus envenomation – a painful learning experience. Medical Journal of Australia. 157: 829-32.
  • Fleay, D. (1980). Paradoxical platypus Hobnobbing with duckbills. Jacaranda Press: Milton, Qld
  • Gardner, J.L and Serena, M. (1995). Spatial organization and movement patterns of adult male platypus Ornithorhynchus anatinus (Monotremata: Ornithorhynchidae). Australian Journal of Zoology. 43:91-103.
  • Grant, T.R. (1985). The platypus: a unique mammal. University of New South Wales Press, Sydney.
  • Gregory, J.E., Iggo, A., McIntyre, A.K. and Proske, U. (1987) Electroreceptors in the bill of the platypus. Journal of Physiology. 400:349-366.
  • Gust, G. and Handasyde, K. (1995) Seasonal variation in the ranging behaviour of the platypus (Ornithorhynchus anatinus) in the Goulburn River, Victoria. Australian Journal of Zoology. 43:193-208.
  • Kruuk, H. (1993). The diving behaviour of the platypus (Ornithorhynchus anatinus) in water with different trophic status. Journal of Applied Ecology. 30: 592-598.
  • Obendorf, D.L., Peel, B.F and Munday, B.L. (1993). Mucor amphiborum infection in platypus (Ornithorhynchus anatinus) from Tasmania. Journal of Wildlife Disease. 29:485-487.
  • Proske, U. (1990). The electric monotreme. Australian Natural History. 23:289-295.
  • Serena, M. (1994). Use of time and space by platypus (Ornithorhynchus anatinus: Monotremata) along a Victorian stream. Journal of Zoology, London. 232:117-132.



Written by Wildlifeqld