Ornithorhynchus anatinus [or'
nith O rin kuhs an ah' tin uhs]
One of the oddest looking
animals on Earth, the duck-billed platypus looks
like it was created from parts left over from
other animals. It has the streamlined body and
short limbs of an otter, a bill like that found
on a duck, and the broad, flat tail of a beaver.
The forefeet are fully webbed, while the hind
feet are only partially webbed. There are five
digits per foot, each ending in a broad
nail on the forefeet and a sharp claw on the hind
feet. Males also have a hollow spur on the ankle
of each hind foot that can deliver a venom
capable of killing a small dog and causing
excruciating pain in an adult human. The animal is 15-1/4 to 23-1/2 inches
long and weighs 1-3/4 to 5-1/2 pounds; males are
generally larger than females. The three-layered
fur ranges from medium to dark brown in color on
the dorsal side and from brown to silver-gray on
the ventral side.
Like river otters, platypuses are built
for swimming, with the heavily webbed
front-feet providing propulsion through water,
while the hind-feet act more like rudders.
Platypuses move a bit more awkwardly on land, but
the webbing on their feet retracts to expose
individual nails and allows the creatures to run.
Platypuses use their nails and feet to construct
dirt burrows at the water's edge.
Platypuses inhabit rivers,
lagoons, and streams in eastern Australia and
Tasmania, usually in water less than 16-1/2 feet
deep. They prefer areas with steep banks that
contain roots, overhanging vegetation, reeds, and
logs. They have been found living at elevations
up to and over 3,280 feet.
Habits and Behaviors
Platypuses are solitary,
especially males, except when mating. If
the territories of males overlap, they usually
change their foraging times to avoid each other.
Platypuses that forage in streams typically have
larger home ranges than those that forage in
Platypuses burrow into banks, creating tunnels
that can be 100+ feet long and that have nesting
chambers at the end. They spend their days in
their burrows, coming out at night to feed.
The platypus swims with its eyes shut. It can
swim underwater for 2 minutes before having to
surface for air, but can stay underwater (if not
active) for up to 10 minutes.
The platypus's bill is soft, flexible, and
covered with sensory receptors that can detect
electrical and tactile stimuli. It uses its bill
to "shovel" aquatic
invertebrates, fish eggs, and small fish from the
stream or lake bed. The findings are stored in
special pouches behind the bill, and are consumed
upon returning to the surface. A platypus can
consume its own body weight worth of food in one
Platypuses mate once a year,
sometime between June and October, depending on
local population. The male initiates most
mating interactions, but successful mating relies
entirely on the willingness of the female.
After a gestation of about 27 days, the female
seals herself inside one of her burrow's chambers
to lay 1-3 soft-shelled eggs. She will incubate
the eggs by pressing them to her belly with her
tail for about 10 days. The platypus is one of
only two mammals to lay eggs, the other being the
echidna. Platypus infants are the size of lima
beans and totally helpless at birth. They lick
milk from the mother's mammary gland, which has
no nipple and simply oozes milk like sweat, for
3-4 months, at which time they can fend for
Platypuses reach sexual
maturity at about 3-4 years, and can live up to
20 years in the wild.
genus & species Ornithorhynchus anatinus
Animal Diversity Web http://animaldiversity.org/accounts/Ornithorhynchus_anatinus/
Australian Fauna http://www.australianfauna.com/platypus.php
BBC Nature http://www.bbc.co.uk/nature/life/Platypus
National Geographic http://animals.nationalgeographic.com/animals/mammals/platypus/
Questions or comments about