Australia's big kangaroos are thriving, but wildlife campaigners hold fears for their smaller cousins, including the little-known bettong and the rock wallaby, WWF Australia has warned.
"The kangaroo is probably the most recognisable Australian animal of all," WWF-Australia spokesperson Darren Grover told AFP ahead of national threatened species day on Sunday.
"But part of that larger kangaroo and wallaby family are all these almost unknown little animals; the bettongs and potoroos and rock wallabies that people haven't necessarily heard of.
"Many of them are really struggling."
Grover said the overwhelming risk to these smaller marsupials were feral cats and introduced foxes, along with a loss of shelter due to habitat loss and changed fire practices.
He said exact numbers of the smaller species were difficult to calculate, but some were only surviving on offshore islands while in other cases mainland populations were under threat.
The northern bettong, which was once found along the northeastern coast, is now only found in four small, isolated populations in tropical north Queensland, WWF said.
And the black-flanked rock-wallaby is only seen in a few isolated groups in remote areas as their numbers have been threatened by foxes and feral cats.
Grover said the kangaroo itself was not at risk, with some of the largest species probably at historically high numbers due to land clearing providing grass and dams a good water supply.
But he said the fear was that the 'roo's little cousins would disappear before many people even realised they existed.
"These are animals that not a lot of people have ever heard of but they are just as an important part of Australia's biodiversity as those larger kangaroos and wallabies," he said.
Australia's National Threatened Species Day is held each September 7 to commemorate the date the last known thylacine, or Tasmanian tiger, died in captivity in Hobart Zoo in 1936.