The platypus is found in all freshwater creeks, rivers, and lakes of eastern Australia from the Cooktown area in the north to Tasmania in the south.  It can be found in 26 of 31 river systems in Victoria.  Platypuses like long pools with solid angled banks, slow flowing water, pool depths of one to two meters, plenty of aquatic vegetation, and a good quantity of  water-dwelling  invertebrates. 
      The platypus is protected by law throughout Australia.  Even though it is common in Australia, it is considered vulnerable due to the continuing loss of its natural habitat due to damming, drainage, and pollution.  The population of platypuses has declined in areas close to Melbourne due to human population growth.       The platypus makes two kinds of burrows.  The camping burrow is used by both sexes as a living space except in the breeding season, when it is used as a bachelor apartment.  This burrow is usually semicircular with entrances at each end concealed by overhanging ledges.  These burrows are often found behind tree roots.  The other burrow, a nesting burrow, is dug by the mother for breeding.  She then adds a "nursery" or nesting chamber.  The passage conforms to her shape and is sloped up as a protection against floods.  The entrance is always above water.  She may build her nest with gum leaves, thin willow twigs, or reeds crushed by her bony jaws.  To create ideal brooding conditions, the mother platypus plugs the burrow behind her at several intervals with walls of earth.  These plugs help resist flooding and offer some safety from potential enemies.  Platypuses usually preen and squeeze water from their fur before entering their burrow to keep the burrow as dry as possible.       Throughout the year the platypus must adapt to changes in temperature both on land and in the water.  In the winter the air can be a minimum temperature of -12 degrees Celsius and the water can be a minimum temperature of 0 degrees Celsius. In the summer the maximum air temperature can be 34 degrees Celsius and the maximum water temperature can be 24 degrees Celsius.  Even the temperature in the burrow can be a minimum of 14 degrees Celsius in the winter and a maximum of 18 degrees Celsius in the summer.  The platypus adapts in a variety of ways to these temperature changes.  As the temperature drops, the platypus generates more heat to maintain its normal body temperature.  It does this by increasing its metabolism.  This increase requires more energy which requires more food to be consumed.  This is when the fat stored in the tail can be used if not enough food can be found.  The platypus uses its blood circulation to carry heat to the parts of the body that require it and it reduces the circulation to its hind legs, tail, and bill which do not need as much.  Its dense, waterproof fur also traps a layer of air which provides good insulation against the cold.  In southeastern Australia the platypus has short periods of hibernation or semi hibernation.  These hibernation periods are short and irregular during the cooler months with the longest single recorded period being 6.5 days.