Name.
The platypus's scientific name, ornithorhynchus anatinus, is derived from a combination of the Greek words for "bird-snout" and "duck-like". The word platypus also comes from the Greek for "flat" and "foot". The term "duck-billed" often prefixes platypus but since there is no other type this term is redundant. There is no agreed term for the plural of platypus, with platypus, platypoda and platypuses all being used.
Where.
The
platypus is regarded as locally common throughout its range along
the east coast of Australia, from north-east Queensland through
to south-west Victoria and Tasmania. It is also found on King Island
and on Kangaroo Island, where it was introduced. It is unique to
Australia. It inhabits fresh water streams, ranging from Alpine
creeks in Tasmania through to tropical lowland rivers. Also found
in lakes, reservoirs and farm dams. It prefers areas with steep,
well vegetated banks in which to burrow. The burrow is normally
shallow and rudimentary but breeding females will construct a more
elaborate affair, sometimes up to 20 metres long.
Description The
platypus is a monotreme (monotremes have a single opening for urinating,
defecating and for reproduction). It is one of only three types
of egg laying mammal in the world, the others being the short-beaked
and the long-beaked echidnas. It has a duck shaped bill, webbed
feet, a beaver like tail and is covered in a dark brown insulation
fur. The average length (including tail) varies from 40cm to 55cm
(males are larger than females) and the average weight ranges from
1Kg to over 2Kg (and this does not follow a climatic pattern)The
body temperature of a platypus (as well as the other monotremes)
is 32 degrees C and they are endothermic. The male platypuses have
a venomous spur on the inside of each hind claw, something it uses
for defences. The poison from this is sufficient to kill a dingo
or domestic dog and is said to be so excruciating to humans that
"the victim is rendered almost helpless". This pain may
last for several weeks.
When
a platypus swims it does so with its eyes, ears and nostrils closed
and so probably cannot sense the non-moving part of its environment.
However, it can sense prey by means of electrolocation, the
ability to detect the tiny electric impulses given off by animals
when they move. The platypus disturbs the bottom of the stream bed
with its bill and in doing so induces movement in prey. It has the
most sensitive electrolocation ability of any mammal. It is nocturnal
and crepuscular. Diet The
platypus is a carnivore, surviving on worms, insect larvae, flies
and small shrimps (yabbies) and other small water borne species.
Once caught the prey is stored in cheek pouches and taken to the
surface where it is ground between the animals' toothless jaws.
It spends around 12 hours per day foraging for food and needs to
consume at least one quarter of its body weight each day. Reproduction Breeding
takes place in late Winter/early Spring, earlier in the north of
the range. One to three eggs are laid (normally two) after two weeks,
the female curling around them for incubation. Upon hatching the
young are blind and hairless and are fed on milk secreted from the
mothers skin Platypuses have no nipples), something that will continue
for three to four months. During this period the mother will only
leave the burrow for short periods and will stop-up the burrow while
she is away. The young will leave the burrow after four months.
The male plays no part in the raising of the young. Conservation The
platypus is considered common throughout its range and the only
area from where it has disappeared since European settlement is
South Australia. However, it is vulnerable to habitat loss, pollution
and from inadvertent capture in shrimp traps. The IUCN classifies
the platypus as "near threatened" on its Red List, mainly
because of the susceptibility to water pollution. Currently
(May '08) the population of Tasmanian platypuses is under threat
from a fungal disease. The disease, which causes ulcers on the tail
and back, has migrated from the mainland where platypuses have a
natural immunity. It is killing about 35% of the population in affected
areas and is spreading. There
has been very little success at captive breeding of platypuses. Main
sources for this information:
Platypus,
Tom Grant, Australian Natural History Series. Field Guide to the Mammals of Australia, Menkhorst
and Knight
Free images.
Please click
any of the images to view a larger version. The simply right click
and save the picture. Images are free for personal and commercial
use. Please do not remove the URL from the full size image.