The report How many are there? The use and misuse of continental-scale wildlife abundance estimates was developed by University of Canberra professor Jim Hone and Invasive Animals Co-operative Research Centre's Tony Buckmaster.

According to the publication, estimates regarding Australian feral cat numbers are believed to be based from a north-west Victorian study from 1982.

Dr Buckmaster said it seemed as though numbers from the study were multiplied by Australia's landmass to achieve estimates of there being anywhere up to 18 million feral cats in the country.

"The truth is we just don't know how many there are," he said.

"Our research shows that we lack the reliable scientific knowledge to give current estimates of feral cat abundance at a continental scale."

Dr Buckmaster said although people tended to gravitate towards population numbers, the impact cats had on the environment was more relevant.

"Unless needed for an eradication program or commercial purposes, knowing the exact numbers of these animals in the landscape is not really important," he said.

"It is much more useful to focus on the damage caused."

Professor Hone said reliable, robust data joined by "good science with strong evidence" was required to build an accurate picture of the feral issue.

To read a copy of the report, click here