Magazine of the Threatened Species Recovery Hub No surprises, no regrets: identifying Australia’s most imperilled species

It was only in 1929 that thylacines were first afforded any protection under legislation. Seven years later they were added to the list of protected wildlife, but the last known individual died that same year. The Christmas Island forest skink was first included on Australia’s list of threatened species in January 2014. Just four months later, the last known individual died. Both extinctions could almost certainly have been prevented if action had been taken earlier. The gnawing question ‘what if we had known earlier...?’ is a recurring theme of frustration and failure in much conservation biology – as it is in human experience generally. When recognition of the imminence of a serious and irretrievable loss is belated, opportunities for better outcomes are fatally lost.

The trajectory and timetable of species to species, and their degree of confidence in extinction was looming larger for the extinction is at least partly predictable. that assessment. Estimates were pooled most imperilled than for mammals. To provide forewarnings, a TSR Hub project, across experts, with weighting by this This may be because many of the most is identifying the Australian animal species confidence level. From this information, imperilled mammals have had some recent at greatest risk and estimating the likelihood we ordered species by their likelihood of reprieves through translocations to that they will become extinct over the extinction, and then summed these estimates predator exclosures and cat-free islands. next 20-year period, if there is no change across species to derive estimates of the One feature of the project to date has been in current management. Our rationale is number of species likely to be become extinct the cooperative involvement of managers and that if governments, managers and the in 20 years, assuming current management. experts from Australian, state and territory community are aware of which species are Our purpose is not to present a doomsday agencies, and conservation organisations. most imperilled, they can take emergency book of damned Australian nature, but This involvement has given the process care to seek to prevent such extinctions – rather to alert responsible agencies and the and results considerable traction among to act before it is too late. community of what will be lost if they do government agencies and NGOs. To some extent, the proximity of a species to not act. And act soon, and act decisively. The project rolls on. Recently, we repeated extinction is already described by a species’ But our results (published at http:// the process for the most imperilled fish, international, national or state/territory www.publish.csiro.au/PC/PC18006) . Species listed as Critically under the guidance of and in collaboration are disconcerting. We are predicting that Endangered are closer to the abyss than are with the Australian Society for Fish Biology. the extinction rate for birds and mammals species listed as Vulnerable, and even more Those results were fascinating and of serious will be higher than at any other time so than the sadly dismissive category of Least concern. Many of the native fish species since European settlement of Australia: Concern. However, many imperilled species considered are not yet listed as threatened we expect seven mammal and ten taxa have not yet had their conservation status under Australian or state legislation, but the will disappear in the next two decades. formally assessed: the forest skink provides experts generally rated them as at greater a valuable lesson that species not listed as Many of the most imperilled species risk of extinction than most listed threatened can still be at risk. Furthermore, the (see table) are poorly known and have threatened bird and mammal species. existing conservation status codings are broad previously received little public attention or Further assessments are now being categories and do not effectively indicate the conservation investment. Happily, Birdlife conducted or are proposed for many amount of time managers may have to act. Australia is now campaigning for some of other animal groups. these uncharismatic but much-troubled birds Our starting point in this research was to (‘Save the Forgotten Flock’: see http:// assemble many experts and all relevant John Woinarski information for Australian birds and mammals. www.birdlife.org.au/current-appeal). Hayley Geyle Based on this information, every expert was Perhaps unexpectedly, given the higher recent Stephen Garnett asked to rate the likelihood of extinction rate of extinctions of Australian mammals within 20 years for the most threatened than of birds, our assessment found that

2 Science for saving species #8 The 20 Australian birds most at risk The 20 Australian mammals most at risk of extinction over the next 20 years of extinction over the next 20 years Mean Mean likelihood of likelihood extinction of extinction within within 20 Rank Species or sub-species 20 years (%) Rank Species or sub-species years (%) King Island brown thornbill Central rock-rat 1 94 1 65 Acanthiza pusilla archibaldi Zyzomys pedunculatus* Orange-bellied parrot Northern hopping-mouse 2 87 2 48 Neophema chrysogaster* Notomys aquilo* King Island scrubtit Carpentarian rock-rat 3 83 3 44 Acanthornis magna greeniana Zyzomys palatalis Western ground parrot Christmas Island flying-fox 4 75 4 41 Pezoporus wallicus flaviventris* Pteropus natalis* Houtman Abrolhos painted button-quail Black-footed tree-rat (Kimberley 5 71 Turnix varius scintillans 5 and mainland NT) 39 Mesembriomys gouldii gouldii Plains-wanderer 6 64 Pedionomus torquatus* Gilbert’s potoroo 6 36 Potorous gilbertii* Regent 7 57 Leadbeater’s possum Anthochaera phrygia* 7 29 Gymnobelideus leadbeateri* Grey-range thick-billed grasswren 8 53 Nabarlek (Top End) Amytornis modestus obscurior 8 29 Petrogale concinna canescens Herald petrel 9 52 Brush-tailed phascogale (Kimberley) Pterodroma heraldica^ 9 28 Phascogale tapoatafa kimberleyensis Black-eared miner 10 47 Brush-tailed rabbit-rat (Kimberley, Top Manorina melanotis 10 25 End) Conilurus penicillatus penicillatus* Northern eastern * 11 39 Western ringtail possum Dasyornis brachypterus monoides 11 25 Pseudocheirus occidentalis* Mallee emu-wren 12 34 Northern brush-tailed phascogale Stipiturus mallee* 12 23 Phascogale pirata Swift parrot 13 31 Mountain pygmy-possum Lathamus discolor* 13 22 Burramys parvus* Norfolk Island boobook 14 27 Kangaroo Island dunnart Ninox novaeseelandiae undulata* 14 22 Sminthopsis griseoventer aitkeni* Mount Lofty Ranges chestnut- 15 rumped heathwren 24 Brush-tailed rabbit-rat (Tiwi Islands) 15 21 Calamanthus pyrrhopygia parkeri Conilurus penicillatus melibius* Fleurieu Peninsula southern emu-wren Silver-headed antechinus 16 17 16 20 Stipiturus malachurus intermedius Antechinus argentus Helmeted honeyeater Southern bent-winged bat 17 17 17 18 Lichenostomus melanops cassidix* Miniopterus orianae bassanii Cocos buff-banded Black-tailed antechinus 18 17 18 17 Hypotaenidia philippensis andrewsi Antechinus arktos Western bristlebird Northern bettong 19 16 19 14 Dasyornis longirostris Bettongia tropica Alligator Rivers yellow Tasman Peninsula dusky antechinus 20 15 20 14 Epthianura crocea tunneyi* Antechinus vandycki

^ Refers to Australian breeding population. *Australia’s Threatened Species Strategy *Australia’s Threatened Species Strategy (2016) includes ten mammals from Table 1 (2016) includes ten birds from Table 1 as priorities species. as priority species.

No. 1: Central rock rat No. 11: Western ringtail possum No. 11: Black-eared miner No. 2: Orange-bellied parrot Photo: Peter McDonald Photo: JJ Harrison CC BY SA 3.0 Wikimedia Commons

Photo: Kaori Yokochi, Photo: Ron Knight Roberta Bencini CC BY 2.0 3 CC BY 4.0 Wikimedia Wikimedia Commons