Biological Diversity 2003 

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Platypus swimming, image courtesy of the Department of Zoology, University of Canterbury.

Click here to hear a platypus growl. Platypus growl only when threatened. Courtesy of the Tasmanian Parks and Wildlife Service.

Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Subclass: Prototheria
Order: Monotremata
Family: Ornithorhynchidae
Genus: Ornithorhynchus
Species: Anatinus

Some platypus images

A platypus exiting the water. Image courtesy of the Burnie Field Naturalist Club, 2003.

A mother with her newly hatched young. The young are born without fur and claws and their eyes are not open. Image courtesy of the University of Michigan's Animal Diversity Web, 1997.

A young platypus starting to grow fur but whose eyes are still unopened. Image courtesy of the Unique Australian Animals Web site, 2003.

A platypus diving to forage for grubs underwater. Image courtesy of the Unique Australian Animals Web site, 2003.

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The male platypus's poisonous spur is very painful to humans and can be lethal to some animals. Image courtesy of Tamar Simon and the Discovery Channel Canada Online, 1999. Click on the link for other images and two videos of platypus in the wild.

A map of the distribution of the platypus in Australia and Tasmania. Image Courtesy of the Unique Australian Animals Web site, 2003.

To see a movie of a platypus swimming, go to

Conservation Organizations

Australian Platypus Conservancy: an Australia based group conducting research programs, conservation programs and environmental education about the platypus.
Go to:

Environment ACT: a branch of the Australian government that strives to protect and educate about the natural environment of Australia. Go to:



      The platypus is a monotreme. The monotremes are the only order of mammals to lay eggs; in this, the platypus is similar to reptiles. Also like reptiles, platypus produce vitamin C in the liver. The platypus produces milk to feed its young (like all mammals). Also like mammals, monotremes have a four-chambered heart and are covered in fur. The life span of the platypus is not exactly known, but it is estimated between 15-18 years.

Reproduction: Normally a solitary animal, the platypus is only social during mating season (September). The platypus reaches sexual maturity at two years of age. Platypus lay clutches of 1-3 eggs. The eggs have a thin, leathery shell. The female incubates the eggs for 10-12 days till the young hatch. The young have no fur and their eyes are not open. After six weeks the young have fur and their eyes are open. Platypus milk is not excreted from nipples, but from ducts at two areas on the abdomen (Tasmanian Parks and Wildlife Service, 2002). After 4-5 months, the young are weaned.

Platypus live along the edge of the shallow rivers and streams where they forage for food. The platypus prefer banks with plenty of natural plant growth. Platypus (both sexes) dig individual resting burrows for protection from predators. Females dig more complex nesting burrows for incubating the eggs and rearing the young, who leave the burrow once weaned (Scott, Anthony and Grant, Tom 1997).

Diet and Feeding: Platypus eat grubs: shrimp, worms, yabbies, pea-shell muscles and aquatic insects. They forage at night from the bottom of streams and ponds. Platypus automatically close their eyes and ears in water. To locate prey, the platypus use their bill. The platypus bill has hundreds of tiny receptors which respond to touch and tiny electro-currents produced when invertebrates move in water (Chambers Wildlife Rainforest Lodges, 2002). The young have teeth but the adults have horny, rigid plates for crushing prey (Missouri Botanical Gardens, 2002).

Predation and Defense: Male platypus have a hollow, sharp single spine on each of their hind legs. The spines secrete a lethal venom produced in a gland in the groin (Chambers Wildlife Rainforest Lodges, 2002). Poison is produced at higher levels during mating season, when the males are competing for mates (Australian Platypus Conservancy, 2003). The spine can also be used a defensive weapon against predators. The platypus's main predators are large birds of prey, crocodiles, dogs, cats, and foxes. The young in nesting burrows are threatened by pythons, water-rats, and guannas (Australian Platypus Conservancy, 2003). The platypus spine is very painful, but not lethal to humans (Tasmanian Parks and Wildlife Service, 2002).

  Platypus are found along the eastern coast of Australia in Tasmania, Victoria, New South Wales and Queensland. There is one introduced population in South Australia but the platypus is otherwise extinct from that area.

Conservation Status

      The platypus conservation status, as listed on the endangered species list by the Australia and New Zealand Environmental Conservation Council, is 'secure but faces future threat'. Most information sources list the platypus as 'common but vulnerable'.

Conservation Issues

      Europeans hunted the platypus for its fur which greatly reduced the numbers of platypus. At the turn of the 20th century, however, trapping regulations were imposed (Scott, Anthony and Grant, Tom 1997). Currently commercial and illegal fishing nets pose a threat to the platypus, which are often caught and drowned. Regulations increasingly limit the fishing industry and regulate the size of nets to decrease the possibility of harming platypus (Scott, Anthony and Grant, Tom 1997).
      The Platypus, like many wild animals is affected by human litter. Plastic rings, from a variety of sources can strangle, incapacitate or lacerate the platypus in a variety of ways. This causes many injuries and some deaths. In many suburban waterways, over 10% of platypus are affected by various plastic rings (Australian Platypus Conservancy, 2003). Other forms of human litter affect the platypus, particularly discarded machinery which leaks gasoline and oil.
       Encroaching human habitation along streams and rivers where platypus make their burrows has many strong effects on the platypus. Paths, whether paved or unpaved, along waterways can lead to erosion, increased access to burrows by predators, and vertical surfaces make it difficult for the platypus to enter and exit the water. Decrease in vegetation along waterways also affects the platypus. This can reduce prey for the platypus and increase access to burrows by predators (Wild Watch, 2001). Another danger posed by encroaching human development is PVC piping along waterways. Platypus often enter open pipe ends and have difficulty turning around and leaving, which inevitably leads to death. Simply putting mesh across the opening of piping would prevent this danger. (Australian Platypus Conservancy, 2003).
      Residential runoff, including detergents and soaps, fertilizers, and livestock wastes lead to increased organic nitrogen and phosphorous levels in water. This affects the platypus by poisoning prey and damaging their fur (Australian Platypus Conservancy, 2003). Simply controlling households wastes and limiting fertilizer use to periods of low rainfall would reduce this threat to the platypus and their habitat.
      Conservation groups, universities and some veterinarians conduct public education services about the platypus and shallow stream habitats. Habitat clean up and other conscientious efforts to maintain shallow rivers and streams will ensure that the platypus does not become endangered.

Literature Cited

Australian Platypus Conservancy. 2003 March 31. 2003 Feb. 29.

Author unknown. 2000 Oct. 25. Platypus web sites. 2003 March 20.

Burnie Field Naturalist Club. 2003 March 5. Wildlife around Burnie. 2003 March 31.

Chambers Wildlife Rainforest Lodges. Date unknown. Platypus. 2003 March 4.

Environment ACT. 2000, day unknown. Home. 2003 April 1.

Integrated Taxonomic Information System. 2003 March 30. ITIS report for Ornithorhynchus anatinus.
. 2003 March 4.

Platypus Computing. 2003, day unknown. What is a platypus? Links. 2003 March 29.

Scott, Anthony and Grant, Tom. Nov. 1997. Impacts of water management in the Murray-Darling Basin on the platypus (Ornithothynchus anatinus) and the water rat (Hydromys chrysogaster).

Simon, Tamar and the Discovery Channel Canada Online. 1999 May 5. The platypus, old and new. 2003 March 31.

Tasmanian Parks and Wildlife Service - Department of Primary Industries, Water and Environment. 2002 Sept. 24. Platypus. 2003 March 4.

Unique Australian Animals. 2003 Feb. 9. Platypus. 2003 March 15.

University of Michigan's Animal Diversity Web. 1997 Nov. 29. Monotremata: life history and ecology. 2003 March 31.

Wild Watch. 2001, day unknown. Platypus. 2003 March 25.



Authors: Mollye Nardi and Emily Whiston
Creation/revision date: 3 April 2003

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This website is part of a Biology 226 class project on the conservation of global biodiversity.

Earlham · Biology Department · Biology 226: Biological Diversity

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