The platypus is a small semi-aquatic mammal endemic to the eastern part of Australia. It is one of the five extant species that make up the order of monotremes, the only mammals that lay eggs instead of giving birth to young.
The male platypus has, in each of its hind legs, a hollow spur, which it uses to inject a venom produced by the crural glands, and which it uses for defense from predators or in fighting for the territory. The absence of the hollow spur in the female platypus, however, does not allow to affirm with absolute certainty that the use of the hollow spur is exclusively aimed at defense.
Since poison appears to have a different function from poisons produced by non-mammalian species, it is possible that it contains peptides or molecules whose main effects are not fatal, but which nevertheless can severely cripple the victim.
There is still no antidote for poison.
Platypus returns to the Royal National Park
The platypus is nocturnal and semi-aquatic, inhabiting small streams and rivers in a vast habitat from the cold mountainous regions of Tasmania and the Australian Alps to the tropical rainforests of the Queensland coasts north to the base of the Cape Peninsula York.
Inland, its distribution is not well known: it is extinct in southern Australia (except for a reintroduced population on Kangaroo Island) and is no longer found in the main part of the Murray-Darling basin, probably due to the declining water quality caused by extensive logging and irrigation plans.
Along the coastal river systems its distribution is unpredictable: it appears to be absent from relatively healthy rivers, yet it maintains a presence in others that are rather degraded. When not in the water the platypus retreats into a short den, straight and of oval cross section, almost always in the bank not much above the water level, and often hidden under a tangle of roots.
For reproduction the female digs much larger and more elaborate burrows up to 20 meters long and blocked at intervals with caps. It nests at the end of the tunnel with reeds as a litter. After more than 50 years, the platypus will return to the Royal National Park, Australia.
If the program proceeds as planned, 10 platypus from other communities will be introduced to the park by the end of next year. Already in other parts of Australia these animals have been introduced into the natural environment and, a few years after their insertion, the new community has begun to reproduce by laying eggs and generating young.