|Regarded as common but vulnerable, the Platypus is distributed in Eastern Australia from the high altitudes and winter snows of Tasmania and the Australian Alps to the tropical rainforest lowlands and plateaus of Northern Queensland. The western limits of its distribution are poorly defined but, in many regions, it seems not to extend westward of the dividing range. There is some evidence that it once occurred in much of the Condamine river in Queensland and in the Murray river and its tributaries in South Australia but it is now extinct in that state, apart from an introduced population on Kangaroo Island.|
The infant platypus has milk teeth but these are not replaced when they are shed. Food collected from the bottom is stored in large cheek-pouches until the animal comes to the surface. It then rests, with its four legs extended, while the food is broken up (indeed 'chewed') between the tongue and an elaborate arrangement of horny grinding plates and shearing ridges on the upper and lower jaws.
When not in the water, a platypus spends most of its time in a short, simple residential burrow just above water level in the bank of a river or stream, under a tangle of tree-roots. This is usually distinguishable from other holes in the bank by its characteristically oval sections and it may be double-ended. The nesting burrow, constructed by a female prior to laying eggs, is a more elaborate structure, up to 20 m long, plugged with earth at intervals, and terminating in a chamber containing a nest of damp herbage.
The Platypus is solitary but substantial numbers may share the use of a relatively small body of water. The extent to which individuals are territorial is not known but reports of combat between individuals indicate that they may defend specific areas. There is a general tendency for foraging to be greatest around dawn and dusk but factors such as locality, human activity, day-length, air and water temperatures, and abundance of food may override this activity pattern, so that in certain places and at certain times of the year, animals may be predominantly diurnal or nocturnal.
Meticulous grooming of the fur is an important element in its behaviour. This sometimes occurs in the water but is more usually carried out on a particular log or rock. The Platypus has a range of vocalisations - a low growling sound is made by an individual when it is disturbed.
The adult male has a sharp hollow spur on each ankle, connected to a large gland in the groin. The gland, which reaches its greatest degree of development in the breeding season, produces a venom capable of causing excruciating pain and incapacity in humans and may be lethal to smaller mammals. It seems that the venom apparatus is used in conflicts between males but, if so, it is a most unusual means of competition. Juvenile females have a rudimentary spur but the structure is lost in adults.
The breeding season varies with latitude. Mating takes place (in the water) around August in Queensland; in September in New South Wales and Victoria; and October in Tasmania. Usually two eggs are laid and these tend to be stuck together, side by side. The female incubates the eggs by holding them against her belly with her tail as she lies curled up in the terminal chamber of her burrow. Eggs hatch 1-2 weeks after being laid and the young feed for 4-5 months on milk secreted from numerous ducts on the mother's abdomen. During the long period of lactation the young remain in the burrow but the female leaves it to forage.
The range of the Platypus extends along the eastern seaboard of the mainland and throughout Tasmania but its distribution is markedly discontinuous. It occurs only in suitable bodies of fresh water and these are under increasing demand for usage which is incompatible with their survival. Dams, irrigation, stream and river bank 'improvements', fish netting and trapping, and chemical pollution are among the hazards that may alienate habitat and lead to reduction or extinction of local populations, since the species has a very limited capacity for recolonisation, successive calamities - even if temporary - lead to continued reduction in the range of the species. Thus, although it is still common in much of its present range, the Platypus must be regarded as vulnerable.
Source: 'Complete Book of Australian Mammals' - Australian Museum, 1983.
Send mail to
with questions or comments about this web site.