The Federal Government's list of plants and animals on the brink of extinction has been updated with 49 new additions — but far from being outraged, scientists and environmentalists say this is a potentially positive sign for those species.

Key points: Species on list given extra protections under environmental laws but 'many neglected'

Species on list given extra protections under environmental laws but 'many neglected' No funding to recover threatened species in budget

No funding to recover threatened species in budget Expert says it is encouraging to see the list growing from a conservation perspective

It is the biggest single addition to the 15-year-old list since 2009 and represents a 20 per cent jump in the size of the list since this time last year.

Threatened Species commissioner Gregory Andrews said Australia was in the midst of an "extinction crisis".

"Australia has endured the worst rate of mammal extinctions in the world ... We've lost 29 mammals in Australia since Europeans arrived," he said.

"Ninety per cent of the animals found here are found nowhere else on Earth. They define who we are as a nation.

"The yellow-footed rock wallaby for example, is one of 16 wallabies at risk of extinction. We've already lost eight wallabies to extinction. They're gone forever.

"I follow the Wallabies rugby team but we can't keep naming our sporting teams after our animals and plants if we lose them to extinction."

'So many of our species have been neglected'

Once a species is added to the list, it is given extra protection under Australian environmental laws.

If it is likely to be affected by a proposed development, the proposal must be vetted by the Federal Environment Minister.

The brush-tailed bettong has almost completely disappeared from the Australian mainland. ( Supplied: Australian Wildlife Conservancy )

Reports on the likely effect on the species must be prepared and potential ways to reduce the impact identified.

A species also should have a recovery plan written for it — but since 2001, few species have had their recovery plans written, and many of those that were written have expired and not been updated.

"The department can't tell me how many have an up-to-date plan," Mr Andrews said.

He said it was a situation he was working to reverse.

"So many of our species have been neglected. So many of their statuses and recovery plans have sat on shelves," he said.

Jess Abrahams, a healthy ecosystems campaigner with the Australian Conservation Foundation, said new funding needed to be found to realise the commissioner's ambition.

"To recover threatened species we need dedicated new funding for which there was none in the most recent budget, and we need a dramatic increase in funding to implement the recovery plans that already exist and are being drafted as we speak," he said.

Encouraging to see species listed from 'conservation perspective'

Professor Corey Bradshaw, Sir Hubert Wilkins chair of climate change at the University of Adelaide, said the dramatic increase in the size of the list reflected a better understanding of the threats facing Australia's plants and animals.

The Condamine earless dragon is listed as endangered. ( Supplied: Steve Wilson )

"Much of the updated information in any sort of endangered species list is usually a function of refined information and better data collection as opposed to an actual, real change in the status," he said.

"Because of the policy implications of a species being listed, it's actually a really good thing from a conservation perspective that we have more species there because it certainly does restrict open-slather development, which has been characteristic of a lot of Australian development over the last 50 years.

"In a lot of ways it's encouraging to see the list growing. The [Environment Protection and Biodiversity Conservation] Act lists probably only a tiny fraction of the species that are truly in conservation peril simply because of a lack of information."

Mr Abrahams agreed, but added a note of concern.

"In part we're seeing more species added to the list as we understand more about the threats to our environment ... but we're also seeing new species added because the Government is failing to do the necessary action," he said.

"Species like the swift parrot or the Leadbeater's possum have been upgraded on that list — they've moved from endangered to critically endangered — and that actually shows that the actions that we're taking are failing."