Rakali

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. 

Misunderstood and Underappreciated: Our Native Rodents

Rodents.

Millions of people have a phobia of them and many more find them just plain revolting. They’ve been demonised more than a few times in popular culture – after all, J. K. Rowling certainly didn’t do them any favours with her character Scabbers. I’ve got to admit, for a long while I was among the people who scrunched up their faces at the idea of having to hold one. After doing some research though, my mind started to change – at least, for our Australian species. Rodents are the most abundant group of mammals on Earth, with over 2,700 species described within the group. Of these, more than 60 are found within Australia, across every state and territory.

The pebble-mound mouse. I mage: Wiki Commons

The pebble-mound mouse. Image: Wiki Commons

While some people may recoil at the idea of so many different rodents found throughout the nation, how they got here is actually quite extraordinary. Australia became a separate land mass 50 million years ago, but rodents reached the continent much more recently. The first wave of rodents arrived between five to eight million years ago, and the second wave, which was almost solely species within the genus Rattus, came in the last one million years. Both these waves were aided by the rising and falling sea levels around the Indonesian Islands, which are believed to be the origin point for our native rodent species.

Since their introduction to Australia, rodents have dispersed and diversified in extraordinary ways. In the northern states of Australia, a group of mice called pebble-mound mice are the only mammals on earth that construct mounds of small stones around burrows. Hopping mice are another unique group of rodents that are only found in Australia, moving in a hopping motion very similar to our native marsupials, despite there being no close relation between the two groups. In the southern states, the New Holland mouse is a social species that is particularly resilient to fire, with its population often increasing after an event. As well as being highly unique, rodents often aid the ecosystems in which they’re found, with recent studies finding that many species are responsible for spreading mycorrhizal fungi, which is crucial to the survival of various trees within Queensland’s tropical rainforests.

The New Holland mouse.  Image: Zoos Victoria

The New Holland mouse. Image: Zoos Victoria

If these species don’t fit in very well with what you imagine when you think ‘rodent’, it’s most likely because the images we typically have of rats and mice are actually invasive species. While the house mouse, black rat and brown rat are all found here, they were actually introduced by European settlers who brought them to Australia – and most of the world – on their ships. While Australian species can be carriers for disease, and it’s not advised for you to go and pick one up, it’s the invasive species that have been linked most closely to the spread of disease and infection.

Rodents make up about one quarter of Australia’s mammals, and are key parts of our environments and ecosystems – but unfortunately, despite their importance, they haven’t escaped the impact of their cousins’ reputations. Habitat destruction and predation from cats, dogs and foxes are major drivers for the decline of our native species. Despite this, funding for research and conservation for rodents is difficult to obtain, due to the stigma surrounding the words ‘mouse’ and ‘rat’. Since European settlement, half of our hopping mice species have gone extinct. Stick-nest rats, a group of rodents that construct their nests out of a variety of sticks and other plant material, are now extinct on mainland Australia. Many species, such as the smoky mouse, are being threatened by habitat destruction. As Australia’s human population increases, we continue to encroach on our native rodents and their habitats, often with devastating results. Since European settlement, an estimated 36% of native rodents have become extinct.

The rakali. Image: Zoos Victoria

The rakali. Image: Zoos Victoria

However, not all the news about our native rodents is bad. The water rat, also known as the rakali, has managed to recover after almost being driven to extinction. The species was nearly eradicated during the hunting trade of the 1930s and 1940s, and later in the 1950s due to people seeing it as a pest. Changes to permits as well as shifts in public attitudes have led to populations making a recovery. Similarly, the New Holland mouse was a species that was thought to have gone extinct for over 100 years, until its rediscovery in the 1960s in Sydney. Since then, conservation programs have been enforced to ensure that we don’t lose the species a second time around.

Approximately 91% of our rodent species are found nowhere else on Earth, and recent genetic work on some species indicates that the diversity may be even greater than what we can see taxonomically. But this diversity can only be preserved if we decide to protect and conserve these species. Like so many animals before them, rats and rodents are misunderstood – but we can change that misunderstanding, if we can just change our perception. 


Cover image by Billy Geary.