Duck-billed platypuses inhabit rivers, lagoons, and streams (Pasitschniak-Artsand Marinelli, 1998). They prefer areas with steep banks that contain roots, overhanging vegetation, reeds, and logs (Grant and Temple-Smith, 1998). The rivers and streams are usually less than 5 meters in depth (Grant and Temple-Smith, 1998). There have been records of them living in aquatic habitats at elevations above 1000 meters (Grant and Temple-Smith, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses are one of three species of monotremes. These species are unique among mammals in that they retain the ancestral characteristic of egg laying. They have a cloaca through which eggs are laid and both liquid and solid waste is eliminated. Duck-billed platypuses are stream-lined and elongated, they have fur ranging from medium brown to dark brown on the dorsal side and brown to silver-gray on the ventral side. They have bills that closely resemble those of ducks, and flat and broad tails resembling those of beavers (Grant and Temple-Smith, 1998). Two nostrils are located on top of their bills and their eyes and ears are on either side of their heads. They have short limbs, naked soles, webbed forefeet and partially-webbed hind feet. Each foot contains five digits each consisting of a broad nail for the forefeet and sharp claws for the hind feet. Males are generally larger than females, and have two venom glands attached to spurs on their hind legs. Females have mammary glands but no nipples. The young have milk teeth while the adults have grinding plates. The young are smaller than adults in size. There is a significant reduction in body fat after winter for both young and adults (Pasitschniak-Arts and Marinelli, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Male duck-billed platypuses initiate most mating interactions but successful mating relies entirely on the willingness of females. Mating is seasonal and varies with population. Male and female platypuses touch as they swim past each other. The male grabs the tail of the female with his bill and if the female is unwilling, she will try to escape by swimming through logs and other obstacles until she is set free. However, if she is willing, she will stay near the male and will allow him to grab her tail again if he dropped it. The male then curls his body around the female, his tail underneath her to one side of her tail. Then he moves forward and bites the hair on her shoulder with his bill. Other details of the mating patterns of platypuses are mainly unknown due to their secretive, aquatic nature. There is a higher proportion of spur wounds in males than females, which may be explained by aggressive encounters between males during mating season. (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses are one of the three mammal species that lay eggs. There is little available information on breeding, estimated gestation periods are 27 days and incubation periods are 10 days. Lactation lasts three to four months. Most juvenile females do not begin to breed until they are four years old (Grant and Temple-Smith, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Female duck-billed platypuses build burrows in which to protect and nurse their young. During the incubation period, the female platypus will incubate eggs by pressing the egg to her belly with her tail. The incubation period usually lasts for 6 to 10 days. Duck-billed platypuses generally lay two to three eggs. ("Duck-billed Platypus", 2008; Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
There is little information on the longevity of duck-billed platypuses. They can live up to 12 years in the wild.
Duck-billed platypuses are solitary, especially males. If the territories of males overlap, they change their foraging time to avoid each other. (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Home range size varies depending on the area, ranging from 0.37-7.0 km. Duck-billed platypuses that forage in streams typically have larger home ranges than those that forage in ponds (Pasitschniak-Arts and Marinelli, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses make some sounds, but their role in communication hasn't been defined yet (Pasitschniak-Arts and Marinelli, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses eat primarily aquatic invertebrates in streams and lakes (Grant and Tempple-Smith, 1998). They also eat shrimp, fish eggs, and small fish (Pasitschniak-Arts and Marinelli, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Predators of duck-billed platypuses include foxes, humans, and dogs (Grant and Temple-Smith, 1998). Others are snakes, birds of prey, feral cats, and large eels (Pasitschniak-Arts and Marinelli, 1998).
There is little information about how duck-billed platypuses affect their ecosystem. However, especially by foraging on aquatic invertebrates, they play an integral role in the food webs of the streams, rivers, and billabongs in which they are found. (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypus skins were harvested by fur traders to make hats, slippers, and rugs. Harvesting was ended by a law passed in 1912 that protected platypuses from being hunted (Grant and Temple-Smith, 1998). (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses eat trout (Salmonidae), which are considered a food source for humans. However, trout streams are not privately-owned in Australia so the effect of platypus predation on trouts is neither widely noticed nor regulated. They can harm humans with their venomous spurs if provoked (Grant and Temple-Smith, 1998). (Pasitschniak-Arts and Marinelli, 1998; Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Duck-billed platypuses are currently protected by the Australian government (Pasitschniak-Arts and Marinelli, 1998). Populations are considered healthy and they are not listed as a species of concern on global conservation lists. (Grant and Temple-Smith, 1998; Pasitschniak-Arts and Marinelli, 1998)
Tanya Dewey (editor), Animal Diversity Web.
Evelyn Ojo (author), University of Maryland, Baltimore County, Kevin Omland (editor, instructor), University of Maryland, Baltimore County.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
union of egg and spermatozoan
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
mainly lives in water that is not salty.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
eats mollusks, members of Phylum Mollusca
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
specialized for swimming
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
having more than one female as a mate at one time
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
places a food item in a special place to be eaten later. Also called "hoarding"
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).
movements of a hard surface that are produced by animals as signals to others
uses sight to communicate
2008. "Duck-billed Platypus" (On-line). the Animal Files. Accessed May 07, 2008 at http://www.theanimalfiles.com/mammals/egg_laying_mammals/duck_billed_platypus.html.
Grant, T., P. Temple-Smith. 1998. Field biology of the platypus (Ornithorhynchus anatinus): historical and current perspectives. The Royal Society, 353: 1081-1091.
Pasitschniak-Arts, M., L. Marinelli. 1998. Ornithorhynchus anatinus. Mammalian Species, 585: 1-9. Accessed April 22, 2008 at http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-585-01-0001.pdf.