Autumn is a great time to set up a blanket by the Yarra at dawn or dusk with a thermos of tea and gaze out at the water and now we have found the best excuse ever to do just that — Melbourne Water is calling on citizen scientists to help spot the elusive platypus.
With the sustained drought over the first ten years of this century, platypus were struggling, however researchers are hopeful that the monotreme’s population is on the rise again.
Jean-Michel Benier from Melbourne Water told the Diary that the Yarra tends to be a refuge to platypus in times of environmental stress — such as drought, flood or bushfire.
“When conditions are good we see more platypus in tributaries, such as the Diamond Creek, Mullum Mullum, and even one recently sighted in Darebin Creek for the first time in 10 years,” he said.
Research partner and wildlife ecologist Josh Griffiths from Cesar Australia said that the Yarra is immensely important for platypus populations.
“Mullum Mullum creek is actually one of the creeks that didn’t show a decline during the drought, even though it is quite a small creek because it is still connected to the Yarra and there is a relatively healthy population in the Yarra — we think the animals keep coming in and out.
“That deeper water of the Yarra provided a bit of a buffer against the drought, so when a lot of these creeks dried up the animals moved into the Yarra and as the water comes back, they move back into those little creeks — so you know the Yarra river is incredibly important for these animals”, said Mr Griggiths.
The research team are pleased that platypus numbers — since the end of the drought — are beginning to increase due to increased water availability and the continuing work of cleaning up the environment.
“There is more water around which means better conditions generally and there has also been a number of habitat improvement works happening, Melbourne Water, and other community groups, do things like weed removal and revegetation, remove litter out of creeks, stabilise banks — create better habitat for them to live in,” said Mr Griffiths.
Melbourne Water have partnered with Cesar to study the health of platypus populations and they need your help.
They have released a website and a smartphone app to collect data on wild populations in the Yarra River and across the rest of the country.
“We would love for people to contribute their observations of platypus to our PlatypusSPOT program,” said Mr Bernier.
The PlatypusSPOT website and smartphone app allows users to upload photos and descriptions of platypus seen in the wild.
“These observations help us to monitor the location and abundance of platypus across Melbourne,” he said.
How to spot a platypus.
Josh Griffiths says spotting platypus in the river can be very difficult.
“Even for myself, who has seen hundreds of them, they can be difficult to see, because they live in the water and they have a very low profile in the water — they don’t stick up like a duck,” he said.
Platypus are most often active at night, so platypus are best spotted at dawn and dusk.
“Look out for some ripples in the water to suggest there is something there, then there is the fur and the low profile to distinguish it from a duck — the thing they get confused with quite a bit is our native water rat (rakali) and they can look very similar in the water — so look for the distinctive bill of the platypus or the nice rounded tail, Mr Griffith said.
Jean-Michel Benier suggests the main ingredients for spotting platypus: “Patience and luck!”.
“It is best to sit in one place for about 20 minutes and observe any bubbles and ripples on the surface of the water — Platypus will generally dive for around 30 seconds then float at the surface to consume their food for around 10 seconds,” he said.
The PlatypusSPOT app contains more tips and photographs that can also help distinguish between a platypus and rakali.
How to help the platypus
“Platypus need deep water, so the less water that we use the more that can go back into the environment, even though the drought is finished it is really important that people are still really water conscious,” said Mr Griffiths
At an individual level there are several ways to help the platypus.
“Platypus often get tangled in litter, fishing lines, or anything that forms an enclosed loop like a rubber band.
“Keep an eye on dogs around the waterway — at this time of the year when there are juvenile platypus starting to come out of the burrows, they are a bit naïve, they get taken by dogs and foxes,” he said.
Of major concern are opera house nets, which are used to catch yabbies and crayfish:
“Unfortunately they are illegal in public waters but they are still used very regularly, I think a lot of people aren’t aware that they pose a risk to platypus and water rats and to turtles that go in those nets and drown very quickly.
“The nets get thrown into the water and they are fully submerged and a platypus can only hold its breath for a couple of minutes, they go in there chasing the yabbies that go in there, so [the traps] basically become a baited trap for platypus – they are still very widely available and I think a lot of people just aren’t aware of the dangers they pose,” he said.
Using technology to track platypus.
As well as using traditional methods, or citizen science projects like PlatypusSPOT, researchers are using increasingly hi-tech, non-invasive, methods to monitor platypus populations.
“We are now also using a new technique called environmental DNA (eDNA), which allows us to take a sample of water from a location and search for DNA markers that are unique to platypus — using this method, we can tell if platypus have been in the water at a given location,” said Mr Benier.
“We can go out and take a water sample and actually look for genetic traces in the water and identify platypus as well as other species in the water – it’s a lot more efficient than going out doing trapping all night and they are quite sensitive and cost effective, so that is providing another avenue where we can monitor the populations”, added Mr Griffiths.
The PlatypusSpot App is available from the Apples Store or Google Play