within this biome, the platypus can live in a variety of ecosystems.
They can be found in:

Tropical rainforests
Subtropical rainforests
Temperate rainforests
Wet or Dry bushland
Sclerophyll forests
Sub-alpine forests

Source: freedawn.co.uk

Adaptations:

1.The platypus bill is used to

locate and digest food

navigate - touch and electro receptors -
cannot use it's eyes and ears underwater
2. The warmblooded platypus has 2 layers of fur

waterproof

insulating layer
3. The nocturnal platypus needs to keep warm,
in the night it stays underwater for up to 14 minutes at a time.
4. It can also regulate blood flow in cold weather
to protect it's internal organs.
5.The tail stores fat

Lifecycle & reproduction:

Source: http://4.bp.blogspot.com

Monotremes are mammals that lay eggs,
the only other monotreme is the spiny anteater echidna

Source : http://4.bp.blogspot.com

Platypuses keep their eggs at the end of the very
long burrows that they dig in the banks.

Eggs hatch after 10 days

Milk comes from special glands on her belly,
They do not have teets or nipples as such, instead the milk
oozes through the fur from these glands for the young to feed.

Behaviour:

The platypus moves it's thick duck like bill from right to left 2-3 times
PER SECOND to navigate and find it's prey. (More in a moment...See Videos)

Nocturnal (hunts under water mostly at night)

When diving, the platypus temporarily stores food in special cheek pouches.
When it is back on the surface to breathe, the food is ground up
very finely between rough pads inside the bill.

Defence:

Venomous Spikes .. could kill a dog .. humans in agony (only in the mating season)

These spikes can be found in the hind legs of a platypus of male platypuses only.
(creeping up from behind - not advisable!)

It's "Sixth Sense" Electrosensitivity - electrical signals and mechanical waves
The surface of the bill is packed with 100s of receptors which respond to touch and the tiny
electric currents produced when invertebrates move in the water, they help navigate too.
Eyes, ears and nose are closed under water.
Check out the video in Link #4

Species & Survival Status:

Not an endangered species

Until the early 20th century, it was hunted for its fur,
but it is now protected. Captive breeding programs - only limited success.

Migration is limited in parts of Australia

The platypus is vulnerable to the effects of pollution,
but it is not under any immediate threat.
(See Video #5 for more details)

Fascinating Facts:

1. Scientists doubted it was real at first. (See Link #3 below)
In 1798, European scientists received a pelt and sketch were
sent back to Great Britain by Captain John Hunter,
British scientists' first assumed that the attributes were a hoax (Wikipedia)

2. In 1943, The prime minister, Winston Churchill requested a live
platypus to be delivered during the second world war,
unfortunately it died on the way and he had it stuffed for his office. Historic background

3. The babies are called 'puggles'. See below.

4. Naturally buoyant, so need to keep swimming to stay underwater

5. A platypus protects its eyes and ears by automatically closing them underwater,
they even have flaps to protect their eyes.

6. Platypus do not actually hibernate, but go intotorpor when they allow their body temperature to drop,
remaining inactive for up to about six days.

7. No Stomach

8. Has five toes and webbed feet

You see, the platypus really is an extroadinary creature!