Scientists are using nuclear physics to track and potentially save Australia's declining waterbird numbers — and they are doing it with discarded feathers.

The team of researchers are using a new method developed at the Australian Nuclear Science and Technology Organisation (ANSTO) to work out where a bird has been and what it has eaten using the chemical composition of the feathers.

The analysis is providing crucial information to help governments plan to protect wetlands and the declining number of birds that inhabit them.

But scientists find it hard to work out by exactly how much because populations fluctuate between floods and droughts.

So how does it work?

An x-ray image of showing a peak in Chlorine in pink from a straw-necked ibis. ( Supplied: ANSTO )

Thanks to a machine called the I-TRAX Core Scanner, scientists can track the exact chemical composition of the feather and work out how it has changed over time.

"What it does is it takes a high resolution photo, an X-ray image and uses a technique called X-ray flourescence to work out chemical elements," ANSTO researcher Patricia Gadd said.

Feathers are made of keratin — the same protein in human hair — and track the diet of the bird in chemical elements.

"Like different restaurants that you would eat at, different wetlands have different diets and signatures that get incorporated into the feather," project leader Kate Brandis from the University of New South Wales said.

Scientist can track where the bird has been by the chemicals in certain parts of the feather. ( Supplied )

Once they have analysed the chemical elements, a mass spectrometer is used to do an analysis of carbon, nitrogen, oxygen and hydrogen isotopes in the feather.

"Nuclear physics gives us new technologies to get at the same answer we would have used older technologies for such as banding or tracking or just purely observational information," Dr Brandis said.

"So it's opening up a whole new world of analysis that we can do on these feathers."

From this information, they can match it up with isotope information from water sources to reveal where the birds have been.

Analysing feathers is cheaper and less time consuming than traditional satellite tracking or leg banding methods.

But how do they get the feathers?

Nuclear physics is giving scientists an unprecedented level of analysis of the feathers. ( Supplied )

Project leader Kate Brandis wants the public to get involved. She wants you to send her as many waterbird feathers as possible.

"So when they go travelling around Australia or visit their local wetlands if they see any feathers on the ground or in the water, pick them up and post them in to us so that we can analyse them and add them to our feather map," she said.

"At the end I'm hoping to have a map of all the different wetlands in Australia and know what their dietary signatures are so if we have another feather we can analyse it and say this feather was grown at Wetland A."

Dr Brandis has already received a few thousand feathers and students attending the Australian Museum's Science Festival this week will be taught all about the map so they can make a difference.

And if you want to contribute — you can find out more on ANSTO'S feather map website.