Previous range
The platypus now only occurs in Australia.
However, from fossils discovered in Argentina, we
know that the ancestors of platypus were found in South America as well
as Australia until at least 60 million years ago - when the two land masses
were still joined together as part of the southern supercontinent Gondwana.
Current range
The platypus lives only in Australia. Populations
occur in Tasmania, Victoria, New South Wales and Queensland to about as far
north as Cooktown. In South Australia, apart from an introduced population
surviving on Kangaroo Island, the species is considered rare and possibly
extinct in the wild.
Distribution of platypus (shaded
area) in Australia
Platypus occupy a wide variety of permanent streams,
rivers and lakes and may also use temporary or manmade water bodies, particularly
when these are linked directly to streams or rivers.
Geographical variation
Although the fossil record shows the occurrence of
several different platypus-like species, today Ornithorhynchus anatinus is the
only known platypus.
Platypus do vary somewhat from place to place - for
example, animals from Tasmania are somewhat bigger on average than their
counterparts from Queensland. However, no sub-species or distinctive local
races are currently recognised by scientists.
Status
The platypus is officially classified as "Common but
Vulnerable" in Australia. As a species, it is not currently considered to
be endangered.
However, platypus populations are believed to have
declined or disappeared in many catchments, particulary in urban and agricultural
landscapes. In most cases, the specific underlying reasons for the reduction
in numbers remain unknown.
Number of platypus
Platypus surveys have only been carried out in a few
catchments in eastern Australia. It is therefore impossible to provide an
accurate estimate of the total number of platypus remaining in the wild.
Based on recent studies, the average platypus population
density along relatively good quality streams in the foothills of Victoria's
Great Dividing Range is only around one to two animals per kilometre of
channel. Because platypus are predators near the top of the food chain
and require large amounts of food to survive (up to about 30% of a given
animal's body weight each day), it is believed that their numbers are most
often limited by the availability of food, mainly in the form of bottom-dwelling
aquatic invertebrates.
Legal protection
Until the early twentieth century, platypus were widely
killed for their fur. The species is now protected by law throughout Australia.
Platypus in captivity
Platypus are wild animals with specialised living
requirements. It is illegal for members of the public to keep them in
captivity. A platypus which has been accidently captured along a stream
or found wandering in an unusual place should never be taken home and treated
as a pet, even for a brief time. The animal will not survive the experience.
Only a small number of Australian zoos and universities
hold permits to maintain platypus in captivity for legitimate display or
research purposes. Current Australian government policy does not allow
this species to be taken overseas for any reason.
