There are lots of creatures using our waterways and if you don’t know what you’re looking for it can be difficult to make a positive identification. It is important that our surveys are reliable and that mistaken identity doesn’t impact the data we collect. For that reason, new volunteers must learn how to determine whether specific splashes and trails in the water indicate the presence of a platypus or something else. A platypus sighting should only be recorded when you are one hundred percent sure that you have seen one. Here are some tips on specific things to look out for and how to differentiate platypus from some of the other animals in the water.
When platypus dive down to the bottom of the river bed they leave a circular ripple with bubbles in the middle. If you see this on the surface of the water there may indeed be a platypus beneath the surface. However, don’t confirm your sighting too soon, turtles also sometimes leave this same pattern when they dive. Don’t despair however as there is a way to confirm your sighting that works almost every time. Unlike turtles, platypus can’t stay under the water for very long and so will re-surface within a minute or too. If you see this ripple, don’t take your eyes off the water for a couple of minutes. If it was a platypus, you should see it resurface. If it was a turtle, you won’t see anything. Simple!
As animals swim along the surface of the water they leave a trail behind them. A platypus keeps it’s body straight while swimming, propelling itself from underneath using its feet. This means a platypus will leave a perfect V shaped trail in its wake.
Rakali (Australian water rats) can often be mixed up with platypus as they are of a similar size, colour and general appearance. The main way to tell the difference between these two species, particularly if you are seeing them from a distance, is the trail they leave behind them. As we have already covered, platypus leave a perfect V in their wake. Rakali on the other hand have a different swimming style to platypus and swing from side to side, which creates more of an S shaped trail.
There is also the other tell-tail signs of the while tipped tail and the ears popping up above the water, which you will be able to see if you are close enough.
The other common mistaken identities, believe it or not, are ducks! You’d think it would be fairly easy to differentiate between a duck and a platypus, but at that time of the day the light is hitting the water in weird ways and can easily deceive you. Like platypus, ducks keep their body stationary when swimming, paddling with their feet underwater, so they also leave that V shaped trail behind them. If you’re seeing them from a distance it can be easy to mistake the two so make sure you always take a second glance to confirm there isn’t a duck sitting on top of the water at the base of the V.