How bringing platypuses back to the River Torrens could be the next step in rewilding Adelaide

12 Aug. 2021
5 min read

Platypuses might be reintroduced back to the River Torrens/Karrawirra Parri. Here’s everything you need to know.

Platypuses have been considered extinct from the wild on mainland South Australia since the mid-1970s. It’s a far cry from the late 1880s when they were common in the city’s River Torrens/Karrawirra Parri and some other Greater Adelaide waterways.

*River Torrens looking east in approximately the 1900s when the river became degraded and platypus numbers dropped. (Image courtesy of the State Library of South Australia* – B 26486)

Today, platypuses can only be reliably found in the wild on Kangaroo Island, after a successful translocation in the 1920s.

There were some sightings in the Riverland during the 1990s, and more recently in 2018, but unfortunately there isn’t any evidence of populations – in social media world we’d just say: ‘pics or it didn’t happen’. With eDNA (environmental DNA) sampling taking place nowadays, this could soon be another option to get proof of these platypus populations.

But back to the story. While there has been an absence of platypuses in the wild on mainland SA, this could soon very well change.

Our friends at Green Adelaide are leading the development of a six-month scoping study to better understand the possibility of bringing platypus back to the River Torrens/Karrawirra Parri.

Here’s everything you need to know:

Why focus on the platypus?

Platypuses are listed as a threatened species in Australia and are endangered in South Australia.

They are a unique mammal with a bill like a duck, a tail like a beaver, fur like an otter, and webbed feet like… we’re back to ducks again.

Oh, and they lay eggs – just like echidnas do. These types of animals are known as monotremes – mammals that lay eggs, and have no teats.

How bringing platypuses back to the River Torrens could be the next step in rewilding Adelaide — (Image courtesy of PlatypusSPOT)

The iconic Australian platypus is what is known to ecologists as an umbrella species – meaning that conserving them and their habitat will result in many other species also being conserved.

So, if platypuses can be successfully reintroduced to the River Torrens/Karrawirra Parri, this will mean a healthier ecosystem for other native species like long-necked turtles and native water rats (rakali).

Plus, having these interesting creatures in Adelaide’s waterways again could also be a nature-tourism drawcard.

Why the River Torrens/Karrawirra Parri?

There are records of platypuses living along the River Torrens/Karrawirra Parri in the early 1800s, and they are now a missing vital part of the River Torrens/Karrawirra Parri ecosystem.

Returning platypuses to the river would be an incredible mark of success for Adelaide’s ‘Hills to the sea’ 85 km River Torrens restoration efforts over the last 40 years.

Is the River Torrens/Karrawirra Parri healthy enough for platypuses to survive?

We think so…and the scoping study will give Green Adelaide the information to make this call.

The Torrens is and always will be brownish like most of Australia’s rivers, like the River Murray. This is due to the tannins in Australian vegetation and soil.

The River Torrens/Karrawirra Parri has come a long way, and with today’s improved native vegetation and water quality – thanks to lots of recovery work by many experts over the years – it’s the right time to investigate reintroducing platypuses to the river.

Also, there is a strong population of rakali along the Torrens today, so if the river is supporting these native mammals already, platypuses may have a good chance at a good life there too.

What will the study scope?

The scoping study will reveal the suitability of the Torrens for platypus to live a good life.

Things like food availability, space and the flow of the river (for safe platypus movement) will be investigated as they are key to platypus survival.

The study will also explore the types of risks that would need to be managed. For instance, there’s opera house traps (yabby nets) that can drown platypuses, water pumps that can suck them up, as well as predators like foxes that might attack them.

The study will be developed by early 2022 with platypus experts and other key partners. If the study reveals that reintroducing platypuses is indeed possible, then the next steps will be exploring sites along the Torrens and population sources.

How you can help

As the project progresses, a Friends of the River Torrens Platypus Community Group and a Platypus Fund will be developed to further this important work to re-wild the River Torrens/Karrawirra Parri.

You can subscribe to the Green Adelaide newsletter for the latest updates on this project, which forms part of Adelaide’s push to become a National Park City.

Haven’t heard of that yet? Read our story: Everything you need to know about Adelaide’s push to become a National Park City and show your support for Adelaide’s environment by signing the National Park City Charter.

The push to become a National Park City is being driven by our friends atGreen Adelaide. Follow them onFacebookorInstagramto stay up-to-date.

This content was written in partnership with Green Adelaide.

(Main image courtesy of PlatypusSPOT)