Platypus

Common name: platypus

Scientific name: Ornithorhynchus anatinus

Family: Ornithorhynchidae

Conservation status: This species is listed as Special Least Concern in Queensland (Nature Conservation (Wildlife) Regulation 2006).

Description:

A duck-like bill and shy nature has made the platypus one of Australia's most intriguing animals. The platypus is one of only three monotremes. The other two species are Australia's short-beaked echidna and Papua New Guinea's long-beaked echidna. Monotremes are different from other mammals because they have no teats and lay eggs like birds even though they raise their young like mammals.

The platypus is smaller than most people think, males are about 50cm long and weigh about 1.5kg and females are smaller, usually about 40cm long and weighing 1kg.

The first thing most people notice about the platypus is its bill. Very sensitive, the bill is like soft, wet rubber and is used to find food. The platypus's body is covered in thick, dark brown fur and is flat and streamlined. It has a broad, flat tail with short, stout legs and webbed front feet well suited to its life in the water.

The tail acts as a stabiliser when the platypus swims, and is also used for burrowing. Fat is stored in the tail for when food is scarce or when the female returns to her burrow to breed. If the water is cold, platypus can increase their body's heat-production to keep their temperature at around 32 degrees.

Awkward on the ground, the platypus waddles with the webs of its front feet turned back so it can use its claws for digging.

The male platypus has a sharp spur on each ankle. These spurs are connected to a venom gland in each thigh. The venom glands are most active during the spring breeding season, so competing males probably use the spurs in territorial fights.

Habitat and distribution

Platypus are found in eastern Australia from the steamy tropics of far north Queensland to the freezing snows of Tasmania.

In Queensland, platypus live in rivers east of the Great Dividing Range, and are also found in some western-flowing streams. In north Queensland, the range of the platypus is close to the coast. The animals aren't found in Cape York Peninsula.

Platypus make their home in and near freshwater creeks, slow-moving rivers, lakes joined by rivers, and built water storages such as farm dams.

They build a simple burrow in a river bank, just above water level and often among a tangle of tree roots.

Life history and behaviour

Platypus mostly live alone, but can share a water body with several other platypus. Half of the platypus's day is spent in the water looking for food. The rest of its time is spent in its burrow, moving across land or even basking in the sun. During cold southern winters, a platypus can hibernate in its burrow.

Platypus eat small water animals such as insect larvae, freshwater shrimps, and crayfish. The platypus, usually active at dawn and dusk, relies on its sensitive bill to find food. With eyes and ears closed, receptors in the bill can detect electrical currents in the water and can help to find prey.

The platypus has no teeth, and stores its food in cheek pouches to eat on the surface. It chews its food between horny grinding plates and ridges on its upper and lower jaws before swallowing.

Platypus can stay underwater for up to 10 minutes. When swimming, the platypus moves itself with its front feet and uses its back feet for steering and as brakes. Water doesn't get into the platypus's thick fur, and it swims with its eyes, ears and nostrils shut.

In Queensland, platypus mate in August. In the south, mating is about a month later. After mating, the female eats a lot of food and builds a nesting burrow. Experts have found that the nursing burrow can be up to 30m long.

She blocks herself into the burrow with dirt to protect herself from floodwater and predators. Blocking the burrow also helps to keep the nesting chamber at an even temperature and humidity for incubation.

After laying two sticky, soft-shelled eggs, the female curls up to incubate the eggs by holding them to her belly with her tail. Incubation for the 17 mm eggs takes about one to two weeks.

Tiny young are born naked, blind and with undeveloped limbs. After birth, the baby drags itself to its mother's belly, where it suckles on mammary patches where milk oozes onto the skin.

The young stay in the burrow for weaning, while the mother leaves to forage. After about five weeks, the mother spends more time away from her young. At four months, the young venture out of the burrow and are fully grown by the time they're one year old.

Where can you see a platypus?

Platypus are elusive but, if you're lucky, you might see one at Girraween National Park in south Queensland, or Eungella National Park and Carnarvon National Park in central Queensland.

If you want to see a platypus in the wild, find a creek or still pool where platypus are known to live. The best times to see a platypus are dusk or early morning. Platypus have sensitive hearing and are easily disturbed.

Sit quietly and watch the water surface for ripples which usually show a platypus is present. Look for a conspicuous bow wave caused by front feet while paddling. Platypus float low in the water with approximately 10 per cent of their furred body exposed. They duck-dive by arching their back and disappear quietly into a small pool of ripples.

Common cases of mistaken identity

Water rats

• Look for a white tail and pointy face
• Piles of shells on the water’s edge
• Very playful in the water but not rowdy
• Swims with head above water.

Turtles

• Often drop into water from logs when disturbed creating a splash
• Small round head just above the surface
• No body visible above the water.

Water dragons

• Creates a zigzagging bow wave from tail movement when swimming
• When disturbed dives from branches, sometimes from a considerable height
• Swims with head only above water.

Threatening processes

People hunted the platypus for their fur in the early 1900s, but they're now protected. Pollution, algal growths, siltation and destruction of creek bank plants all put platypus homes under increasing pressure. If platypus died from any of these factors, relocating any left from the affected group would be extremely difficult.

Natural predators include snakes, water rats, goannas, foxes, and crocodiles.

How can you help?

Please don't disturb platypus if they live in streams on your property or in your neighbourhood.

You can help the platypus living in your area by keeping natural plants along watercourses. If you do this, you will protect banks and will provide areas for the platypus to live.