platypus

A Rat by Any Other Name

Take a moment and picture a common Australian animal. Here are some clues – it’s small. It lives in rivers and waterways, where its dense fur coat and thick tail make it a sturdy swimmer. It’s shy, staying hidden during the day (less so in winter, when a streamside sunbeam makes a perfect spot to warm up and bask). It eats whatever insects and crustaceans it can fit through its broad, flattened mouth.

Up to this point (if you skimmed past the article title), you might be imagining either one of two Australian natives. The platypus (Ornithorhynchus anatinus) is a familiar emblem of Australia’s creeks, delighting tourist and local alike whenever there’s a spotting. And rightly so – with a soft body, sleepy expression, and harmless appearance, the platypus enjoys a charisma that keeps it in the good graces of the public. This is despite the males having poisonous spurs that can induce months of pain untreatable by morphine.

The Australian platypus in action.  Image: Museum Victoria

The Australian platypus in action. Image: Museum Victoria

However, this isn’t another article about the platypus (and its problematic pluralisation – is it platypi? Platypodes? Platypuses?). It is about language though; the way a species can be perceived, and marketed, and raised as a focal point for campaigns of conservation or destruction.

Hydromys chrysogaster was first described in 1804, at a time when Europeans were still acquiring the vocabulary for Australia’s unique ecosystems. Wombats were native badgers; koalas were native sloths; thylacines were native wolves, and later tigers. The platypus was a beaver, a mole, a bird, a fish, and a hoax, before eventually settling on flatfoot (platypus), bird-snout (Ornithorhynchus), and duck-like (anatinus).

By contrast to the majority, H. chrysogaster was an easy job – in English its name means yellow-bellied water mouse, and it is indeed a member of the mouse family. But for its size, and in the interest of comprehension to foreign naturalists, it was called the Australian water rat.

Ornithorhynchus anatinus , the duck-like bird snout.  Image: NMA

Ornithorhynchus anatinus, the duck-like bird snout. Image: NMA

Hydromys chrysogaster,  the yellow-bellied water mouse.  Image: Museum Victoria

Hydromys chrysogaster, the yellow-bellied water mouse. Image: Museum Victoria

When the English colonised Australia, they saw a vast expanse of opportunity and resources. Modern corporations like the Australian Agricultural Company and the Van Diemen’s Land Company started during the early 19th century, raising cattle and sheep for export back to Europe. The dominant thought – public and private, small and large – was of expanding an empire.

As the frontier of farming communities pushed outward, native landscapes and species suffered. Most famously, Australia saw the extinction of the thylacine after a century of conflict. The Tasmanian tiger was subjected to loss of territory, loss of food, diseases from dogs, and – perhaps most significantly – private and government-sponsored bounties for extermination. The thrill of tiger-hunting was a part of the worldwide British Empire; Rudyard Kipling’s The Jungle Book is a monument to the mood, with human’s triumph measured by the death of the villainous tiger.

Frontier men of the early 1900s earned their stripes collecting bounties on  the   Tasmanian   tiger.   Image:  http://nichaygarth.com/

Frontier men of the early 1900s earned their stripes collecting bounties on the Tasmanian tiger. Image: http://nichaygarth.com/

Animal hunting also had more pragmatic motivations. As late as the 1940s, when the threat of extinction had begun affording Australian wildlife protected status, the fur of the water rat was being used for clothing. The Powerhouse Museum in Sydney holds a coat made from one hundred H. chrysogaster pelts, collected personally by the coat’s owners on personal holidays. The rat was vermin; was common; was not given the unqualified status of other animals. In Victoria, destruction permits in irrigation areas and seasonal hunting permits were issued until 1967; the species had been placed on a protected list earlier in 1938 after the fur trade drove a decline in number.

The rakali coat held in the Powerhouse Museum.  Image: Powerhouse Museum

The rakali coat held in the Powerhouse Museum. Image: Powerhouse Museum

Rebranding the Hydromys with other names, like the ‘Australian otter’, has helped its image simply by providing the public with a different point of reference in understanding its lifestyle. In the 1990s, a (perhaps obvious) decision was made to use Indigenous Australian names for Australian animals – from consulting the ancestral languages across its range, Hydromys was given the name of rakali.

Creating public awareness of the species is important; rakali is an elusive species, with attempts to monitor the population only resulting in trapping rates of 6-30% and usually as a by-product of platypus surveying. However, there is an indication that the species is experiencing population crashes in regions across Australia. An aquatic species is always only tenuously secure in Australia’s climate, and the rakali are vulnerable due to their breeding cycle being broken by drought. The design of modern irrigation channels also creates difficulties, with concreting or plastic lining depriving rakali of opportunities to dig burrows.

The Australian Platypus Conservancy has begun delivering seminars on rakali to local councils, recognising the overlapping benefits of restoring habitat. The apex predator flourishes best in healthy waterways, functioning as a barometer for management regimes. Creating public awareness is also a useful way for more people to understand their own interactions with the environment, for better or worse. The continued use of the popular Opera House nets – and their use is banned in all Victorian public waters – causes the drowning deaths of rakali that become stuck in them, a fate often shared by platypuses and turtles. More positively, the anecdotal evidence of citizen sightings is helping to build a clearer picture of populations across Melbourne and across the year, and can be incorporated into more widespread projects such as Bowerbird and the Atlas of Living Australia.

The wonder and exoticism of Australia’s wildlife has not diminished since it baffled those first Europeans. Through close observations, we will better begin to appreciate the rarity and individuality of our native species. And if the world can learn to love a bird-snouted flatfoot, there’s probably room for the rakali as well.

If you wish to become more involved in citizen science, you can relay your plant and animal sightings to:


Paul Jones

Paul works in science education and has been a teaching member of Monash University's Department of Biology since 2010. He is interested in community engagement and sustainable urban development.



Banner image courtesy of Museum Victoria. 

Monotremes in Suburban Streams: Surveying Melbourne's Platypus Population

Weaving and winding through city suburbs flow the many streams and creeks that make up Melbourne’s water catchment. These waterways extend from the mountain ranges surrounding the city where they carry away excess rainfall, guiding flows seaward into Port Phillip Bay. A multitude of life forms make use of this drainage system, although one in particular seems to capture our attention: an exceptionally peculiar creature renowned for its egg-laying abilities, venomous spurs, duck-like bill and webbed feet - the iconic platypus (Ornithorhynchus anatinus).


One of the many picturesque streams found around Melbourne which are home to Platypuses.

One of the many picturesque streams found around Melbourne which are home to Platypuses.

Despite its well-known identity and presence within metropolitan streams, the majority of Melburnians are unlikely to have seen a wild platypus due to their predominantly nocturnal behaviour and shy nature. For those who have been fortunate enough to sight the elusive creature, it surely proves for a memorable and enlightening experience. This was certainly the case for me whilst recently assisting environmental consultant and wildlife ecologist Josh Griffiths with platypus population surveys in Melbourne’s north-western suburbs.

Platypus surveys are undertaken twice yearly around Melbourne in order to assess population health and determine long-term population trends. The surveys involve setting specially designed traps at fixed locations within Melbourne waterways in the hope of catching platypuses which may inhabit an area. Once a platypus has been caught, various data is collected on the sex, weight, age and health of the individual, with each platypus also being equipped with a unique microchip (the latter being used to identify previously caught individuals in subsequent surveys).

Setting one of the many specially designed Platypus traps used during the population surveys. As can be seen in the photo one trap opens upstream whilst the other opens downstream.

Setting one of the many specially designed Platypus traps used during the population surveys. As can be seen in the photo one trap opens upstream whilst the other opens downstream.

During the volunteer placement, a male individual was caught, which allowed for a close inspection of the formidable venomous spurs that adorn the rear ankles of male platypuses. These impressive spurs, of approximately 1.5 centimetres length, are used against other males during territorial disputes throughout breeding season. In some instances, humans have been envenomated by these spurs, causing prolonged, excruciating pain. However, as Josh explains, given that a platypus is handled competently and correctly (by its tail), the spurs pose little danger to the handler. Nevertheless, as the surveys were undertaken outside of the platypus breeding season, all animals caught were relatively docile and cooperative, lying quietly in white cotton bags whilst the relevant data was collected.

The spur of a male Platypus. The pinkish sheath at the base of the spur denotes that this individual is a juvenile animal.

The spur of a male Platypus. The pinkish sheath at the base of the spur denotes that this individual is a juvenile animal.

A total of three platypuses were caught during the survey - a good result, Josh informed me, indicating that platypus numbers may be finally stabilising after a long, drought-induced decline. Drought led to reduced flows and pooling of many of Melbourne’s waterways, resulting in a drop in overall platypus abundance as individuals generally chose not to breed in the poor conditions or were unsuccessful in doing so. Josh also emphasised that the clearing of riparian vegetation hinders platypus procreation, as the burrows in which the animals rear their young require stable soils held together by tree roots. Nonetheless, such results were encouraging, indicating that the local platypus population and waterways were in good health.

All Platypuses remained relatively calm throughout the handling process. Here an individual’s bill protrudes thorough an intentionally made opening in a cotton holding bag.

All Platypuses remained relatively calm throughout the handling process. Here an individual’s bill protrudes thorough an intentionally made opening in a cotton holding bag.

An unfortunate Platypus who has become entangled in human litter—in this case a rubber wristband. The band was later successfully removed. Photo credit: Josh Griffiths.

An unfortunate Platypus who has become entangled in human litter—in this case a rubber wristband. The band was later successfully removed. Photo credit: Josh Griffiths.

To work with the enigmatic platypus has undoubtedly been an incredible experience. Such research is paramount to conserving this charismatic creature for future generations and to ensure the ecological health and functioning of our waterways. To assist in conserving this unique species, be sure to collect any artificial litter that may end up being flushed into our waterways. Disturbingly, Josh has informed me that of all platypuses caught during the 2013/2014 surveys, 10% were entangled in some form of litter, ranging from wrist bands and hair ties to balloon strings and elastic bands. To aid Melbourne Water and cesar (Melbourne Water’s research partner) in understanding and protecting platypus populations within Melbourne, submit any sightings of the species to the specifically created PlatypusSPOT online database at http://platypusspot.org/.

A Platypus re-enters a creek after being processed, within a second it is fully submerged and very difficult to see as it glides swiftly through the water.

A Platypus re-enters a creek after being processed, within a second it is fully submerged and very difficult to see as it glides swiftly through the water.

Platypus Magic

Did you know that one of Australia’s most unique and charismatic animals lives right on Melbourne’s doorstep? With a duck’s bill, egg-laying ability, a mammal’s fur and a poison barb on their foot, of course I’m talking about the famous Platypus (Ornithorhynchus anatinus). The platypus is about as iconic an animal as you can get, featuring on television shows such as Blinky Bill (who could forget ‘Flap’ the platypus?), in aboriginal dreamtime stories, and even in a song by Green Day.

However, the platypus also plays an important ecological role in addition to its plethora of cultural significance. Being a carnivore, the platypus generally sits atop the food chain in our freshwater rivers and streams. Therefore, it plays a vital role in keeping species such as freshwater crustaceans and aquatic invertebrates in check.

 

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Unbeknownst to many in Melbourne, one can go in search of this fantastic creature without spending longer than an hour in the car. Many of the Yarra River’s freshwater tributaries, as well as the Yarra itself are home to the platypus. Most active during the early morning and late evening, these are the best times to sneak up quietly to the water’s edge and peer into the depths in search of the splash of their thick tail. If you’re lucky enough to spot one frolicking in the shadows, it makes for a truly unforgettable experience.

For an extended introduction to the art of platypus spotting, head to the Australian Platypus Conservancy (APC).

Whilst this beloved animal is listed under ‘Least Concern’ by IUCN (International Union for Conservation of Nature), there is sufficient evidence to show that platypus numbers have decreased in the past decade. The cause of this decline has been linked to two or three different reasons, namely water quality, the use of opera house nets and increased river temperatures as a result of climate change.

 

The platypus is incredibly sensitive to the quality of the river it lives in, particularly in terms of pollution levels and the degree of bank erosion. However, 80% of platypus deaths reported between 1989 and 2009 were related to humans. Specifically, the use of opera house nets to catch freshwater crustaceans and fishermen leaving behind tackle in which animals get caught have been particularly damaging.  

The illegal opera house net, the unfortunate cause of death to hundreds of our special platypuses. 

The illegal opera house net, the unfortunate cause of death to hundreds of our special platypuses. 

As a result, the use of opera house nets in Victorian public rivers and streams is now illegal (carrying a fine of up to $11,000, or even jail). This is due to platypuses continually becoming caught in them whilst looking for food and subsequently drowning (they can only hold their breath for 30 to 40 seconds). On various occasions, three or more dead platypuses have been found in a single, abandoned opera house net. These deaths are completely preventable, and it is up to the wildlife loving public to help ensure these nets do not end up in our waterways.

So, when venturing out around Greater Melbourne in search of your own platypus experience, keep an eye out for opera house nets or fishing line in and around our waterways. Removing and reporting any opera house net use to the Department of Environment and Primary Industries could literally mean the difference between life and death for one of Australia’s most special creatures.

 

 

To report the use of illegal opera house nets in our waterways, call 13 FISH (136 186)