Platypus Awareness and Conservation

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PlatypusQPRC Updated.jpgCLICK HERE TO REPORT A PLATYPUS OR WATER RAT SIGHTING

Platypus are popularly believed to be shy and sensitive. As a result, there is a widespread perception that the species is only found in pristine environments, far from human settlement. In fact, platypus can occur in rivers and creeks close to built-up areas. Queanbeyan is especially fortunate in that platypus are currently found along the length of the Queanbeyan River within the city boundaries and can often be observed, especially at dawn and dusk, close to the city centre.

History

According to Aboriginal Dreamtime legend, the first platypus was born after an attractive young female duck mated with a lonely and persuasive water-rat. The duck's offspring had their mother's bill and webbed feet and their father's legs and handsome brown fur. The Ngunnawal word for platypus is Malunggang.

The platypus was first scientifically described by Dr George Shaw in Britain in 1799. His initial reaction to the first specimen was that it was an elaborate hoax. It was not uncommon at the time for exotic forgeries (such as “mermaids” made by joining the body of a monkey to that of a fish) to be brought back to Europe from far-flung parts of the world. Shaw was so convinced that the platypus specimen had been fabricated that he expected to find stitches attaching the bill to the skin.

The earliest known monotreme, or egg-laying mammal, which unequivocally resembled what we think of as a platypus (based on finding a nearly complete, platypus-like bill) has been named Obdurodon dicksoni and dates from approximately 15-20 million years ago. The earliest known remains of the living species have been dated to around 100,000 years ago.


What does a platypus look like?

Platypus swimming

About half the size of a household cat, platypus are dark brown on their backs and generally light brown on their bellies. Under their long, coarse outer hair is a fine, dense underfur which is woolly in texture. This fur ranges in colour from grey to dark brown.

With their slightly flattened, streamlined body and short, stout legs, they are well-adapted for swimming. The forelegs push the animal through the water, while the hind legs trail behind, acting as stability rudders. When digging a burrow or moving on land, platypuses can fold away their webbed foot extensions.

The platypus has no outer ear lobe, and both its eyes and ears close when it dives. It has very sharp vision over long distances, but because its eyes are towards the top of its head it cannot see objects directly under its nose.

The duck-like bill of the platypus is a flexible, soft and very sensitive organ. It helps the animal to find its way about and to search for food, picking up electrical discharges from its prey. Although it has no teeth, the platypus uses grinding plates on the upper and lower surfaces of the jaw to chew its food.

The platypus keeps its body temperature constant by controlling the heat produced from metabolism (all the chemical reactions that occur in the body). It can reduce blood flow to areas of its body that have no fur - particularly its tail, rear feet and bill. Its fur is waterproof and traps an insulating layer of air next to its skin.

Adult males and females can differ greatly in size and weight. The average male platypus is about 50 cm long (head to tail) while females measure about 43 cm.


Where does a platypus live?

Platypus occupy weir pools, irrigation channels and man-made dams or reservoirs as well as natural lakes, rivers, creeks, backwaters and billabongs. They are generally most readily spotted in places where the water surface is fairly calm, making it easier for observers to identify the ripples formed on the water surface as the animals swim and dive.

Out of the water, platypus spend most of their time in burrows which have been dug into the river bank, with their entrances usually above water level. The animals use a number of short resting burrows (three to five metres long) as protection from predators and temperature extremes. Burrows used for nesting tend to be more elaborate, with many side branches.


How to spot:

Mainly a nocturnal animal, the platypus can best be seen during the early morning and late evening. It spends about half its time in the water feeding. In fact, it can spend up to 10 hours in the water at any one time. Normally a platypus stays underwater for between one and two minutes, but if disturbed it can stay underwater for up to 10 minutes.

  • Concentric rings appear on surface of the water when platypus dive and when they feed on the surface.
  • A trail of bubbles shows their progress underwater.
  • A characteristic ‘bow-wave’ when swimming on the water surface.
  • Burrow entrances in banks are typically 10–15cm in diameter. The burrow entrance maybe beneath the water surface or more commonly from 5cm to 1m above the water level and often hidden by overhanging vegetation.
  • Well-worn slide mark from the burrow directly into the water.
  • Characteristic footprints sometimes left in the soft mud on the river bank, especially near a burrow.

What does a platypus eat?

A platypus usually catches its food underwater, sifting through the gravel and mud of the riverbed. A great deal of mud can be consumed in this process. It fills its cheek pouches with unchewed food, and when it has finished feeding it rests on the water surface to grind and swallow the food. Its diet consists mainly of riverbed animals such as insect larvae. However, platypus also eat freshwater shrimp, and may catch adult insects on the surface of the water.


Threats to platypus:

The conservation status of the platypus has been upgraded to ‘near threatened’ in the latest edition of The Action Plan for Australian Mammals. The Action Plan incorporates input from more than 230 biologists with specialist knowledge about mammals found in Australia, including monotremes, marsupials, rodents, bats, seals, dolphins and whales.

Although the Queanbeyan River’s platypus population currently appears reasonably healthy, it is essential that we all act to ensure that it is protected from the impacts of habitat degradation and other human-related factors. Getting conditions right for platypus, effectively a “top predator” in the river system, will also ensure that things will be pretty good for other native species sharing its habitat.

Litter: Research has shown that, on average, 10% of platypus living in urbanized waterways have something caught around their body, with the entanglement rate being as high as 60% in some areas.

Irresponsible fishing activities: It is totally illegal to use opera house nets and other types of enclosed yabby traps along the Queanbeyan River or in any other river or creek in the area.

Unattended lines: Platypus can be hooked and drowned on unattended baited fishing lines. Unattended lines are illegal.


What is Queanbeyan  - Palerang Regional Council doing?

Queanbeyan - Palerang Regional Council has a crucial role to play in conserving platypus in the Queanbeyan River and the wider Molonglo River upper catchment area. As part of Council's ongoing commitment to conserve biodiversity in the area, the Queanbeyan Platypus Awareness and Conservation Strategy 2012 was commissioned.

Click here to find the Australian Platypus Conservancy's article on the platypus count monitoring program for the Queanbeyan River. 


Platypi or Platypuses?

When referring to more than one platypus, scientists generally use the term "platypuses" or simply "platypus". Colloquially, the term "platypi" is also used for the plural, although this is technically incorrect and a form of pseudo-Latin. The correct Greek plural name for more than one platypus would be "platypodes".