Conservation

Gilbert's Potoroo is known only from a single, tiny natural population on Mount Gardner, in Two Peoples Bay Nature Reserve, near Albany, Western Australia and three translocated 'safe haven' populations that together total only about 100 individuals. It is CRITICALLY ENDANGERED

Conservation Status

As of March 2020, the population of Gilbert’s Potoroo is estimated to number between 100 and 120 individuals divided between four sub-populations. The current conservation status of Gilberts Potoroo is listed as:

Recovery Plan

The Gilbert's Potoroo Recovery Plan (2016) is a Department of Parks and Wildlife Management Program developed to guide management actions necessary to support the recovery of Gilbert's Potoroo.

The Recovery Plan covers these actions in detail but, to summarise the main points, the objectives, criteria for the plan to be considered successful or unsuccessful, and key recovery actions are reproduced below:

Recovery Goals and Objectives:
The long term goal of the recovery program for Gilbert’s potoroo is to improve its conservation status by increasing the size of existing populations and the number of populations.

The specific recovery objectives for Gilbert’s potoroo for the next 10 years are:

Objective 1:  to ensure existing populations of Gilbert’s potoroo are restored and maintained at sustainable levels and genetic diversity is maximised; and
Objective 2:  to increase the number of populations of Gilbert’s potoroo.

In addition to these specific recovery objectives for the species, the following objective is identified as essential for achieving the implementation of this recovery plan:

Objective 3. to increase the awareness of, and support for the recovery of Gilbert’s potoroo.

Recovery Criteria
The Recovery Plan will be considered successful if, within a 10 year period, all of the following are achieved:

  • the abundance in existing populations remains stable or increases to sustainable levels;
  • threatening processes constraining recovery and the establishment of new populations are identified and effectively managed; and
  • the number of populations of Gilbert’s potoroo is increased by establishing at least one new population.

The Recovery Plan will be considered unsuccessful if, within a 10 year period, any of the following occur:

  • the abundance in existing populations declines or does not reach sustainable levels; or
  • threatening processes are not identified and effectively managed, thus preventing the establishment of new populations; or
  • no new populations are established.

Recovery Actions

The Recovery Plan breaks down the three broad Objectives into a detailed and prioritised recovery program. Gilbert's Potoroo Action Group actively works with DBCA and the Gilbert's Potoroo Recovery Team to implement this recovery program:

Objective 1: to ensure existing populations of Gilbert’s potoroo are restored and maintained at sustainable levels and genetic diversity is maximised.

1.1  Review and implement the Fire Management Strategy for Two Peoples Bay – Manypeaks to ensure the negative impacts associated with fire on Gilbert’s potoroos and their habitat is minimised.
1.2  Implement effective, integrated introduced predator control programs at all mainland population sites.
1.3  Undertake regular surveillance of all island and enclosure population sites for introduced predators, and undertake eradication as required.
1.4  Undertake the management of native predators if required.
1.5  Maintain monitoring of all populations to determine population trends and sustainable levels.
1.6  Undertake an assessment of the genetic diversity across all sites *
1.7  Develop and implement a population management strategy (informed by 1.6)
1.8  Maintain the Waychinicup NP enclosure
1.9  Maintain emergency captive facilities
1.10  Investigate habitat use within existing populations *
1.11  Investigate the causes of mortalites in existing population


Objective 2: to increase the number of populations of Gilbert’s potoroo.

2.1  Establish another island/fenced population and manage as outlined in Objective 1. 
2.2  Identify and prioritise potential mainland sites for future translocation where threat mitigation can be tested. This will include investigations and on ground work, such as:

  • Investigate habitat use within existing populations (refer to 1.10). 
  • Apply habitat suitability assessments. 
  • Identify ideal threat mitigation levels for future translocation sites. 
  • Implement effective, integrated introduced predator control programs at potential mainland sites. 
  • Develop and implement suitable fire management strategies at potential mainland sites.
  • Investigate the impact of climate change on abundance and diversity of mycorrhizal fungi.
  • Monitor the effectiveness of threat mitigation trials. 


Objective 3:
to increase the awareness of, and support for the recovery of Gilbert’s potoroo.**

3.1  Develop and apply education and promotion programs about Gilbert’s potoroos, such as: 

  • The education and promotion work of the Gilbert’s Potoroo Action Group in WA.
  • Education programs about threatened species (including Gilbert’s potoroos) in the school curriculum.
  • The Western Shield education package.
  • Provide information to community groups with an interest in threatened species (i.e. presentations).

3.2  Promote the plight of Gilbert’s potoroo and the recovery actions required to all levels of government, NRM groups and non-government organisations.
3.3  Provide opportunities for participation in Gilbert’s potoroo recovery program. 
3.4  Seek resources to undertake Gilbert’s potoroo recovery. 


* This action is being partly addressed by projects funded by our State NRM Community Stewardship Grants
** Gilbert’s Potoroo Action Group is listed as a responsible party for all of the Actions listed under Objective 3 in the Recovery Plan

Threatening Processes

The Gilbert's Potoroo Recovery Plan (DBCA, 2016) identifies 5 main threatening processes that limit the survival of the Gilbert’s Potoroo: 

Fire

Photo: Val Hack

A catastrophic fire that had the potential to destroy all of the habitat of Gilbert’s Potoroo at Two Peoples Bay and drive the species to extinction was recognised as a major threat immediately the species was rediscovered in late 1994. Actions required to protect the single known population were detailed in the Interim Wildlife Management Guidelines adopted in February 1995  (pp 4, 5). A captive colony was immediately established to try to provide animals to create an insurance population but over the following years captive breeding and other assisted reproduction techniques proved unsuccessful.

In 2005 the decision was made by the Recovery Team and the then Department of Conservation and Land Management to abandon attempts at captive breeding and to instead focus on establishing safe haven populations outside of Two Peoples Bay. That decision resulted in the creation of first the Bald Island population from 2005 onwards, and then the population in the fenced enclosure at Waychinicup National Park from 2010. In 2015 an intense lightning storm ignited the long feared fire at Two Peoples Bay resulting in the eventual destruction of over 90% of suitable habitat and leaving only a handful of survivors. The species was saved from certain extinction by the early recognition of the threat posed by fire and the establishment of the two safe haven populations. A third safe haven population was created on Middle Island in the Recherche Archipelago in 2018 by the Department of Biodiversity, Conservation and Attractions, funded by a grant to GPAG from the Commonwealth Department of Environment. Despite the existence of the various sub-populations, fire continues to be a major risk to the long term survival of Gilbert’s Potoroo, particularly the Bald Island population, which now accounts for the majority of the known animals.

Feral Predators

Photo: DBCA

Gilbert's Potoroo is within the Critical Weight Range (35g to 5kg) of mammals thought to be most susceptible to decline. It is in the prey size range of both foxes and cats, both of which are known to occur in the Two Peoples Bay area. Dietary analysis of the gut contents and faeces of a feral Cat trapped at Mt Gardner in 2001 revealed that it had consumed both Quenda (Bandicoot) and Noisy Scrub-bird. Both fox and feral cat control is being undertaken at Two Peoples Bay, and has increased since the 2015 fire in an attempt to protect the handful of survivors. Both Bald Island and Middle Island are free of feral predators, and the Waychinicup population is protected by a feral predator proof fence. However as the Recovery Plan notes, the implementation of feral predator control programs at mainland sites and ongoing surveillance to ensure that the two islands and the Waychinicup enclosure safe haven sites all remain feral predator free are of the highest priority.

Inadequate gene flow

The entire Gilbert’s Potoroo population numbers in the vicinity of 100-120 animals divided between four geographically isolated locations. The low number of animals overall in the four sub-populations and the fact that all the translocated sub-populations were initially derived from the small population of animals at Two Peoples Bay, which itself had low genetic diversity due to its small size and a recent genetic bottleneck (Sinclair et al 2002), potentially limits the ability of the species to adapt and survive in a changing environment. A lack of natural gene flow between the sub-populations further increases the risk of inbreeding. Studies of Gilbert’s Potoroo population genetics and genome being funded by a State NRM Community Stewardship Grant to GPAG will help to inform the development of a population management plan by DBCA scientists to manage the genetics of the species across all four locations.

Climate change

Climate modelling predicts that in the south-west of Western Australia, mean minimum and maximum temperatures will continue to increase, annual as well as winter and spring rainfall will continue to decrease (although heavy rainfall events may increase), and dry lightning storms will increase in frequency. These changes will all, in turn, lead to increased drought conditions and more frequent and severe bushfires. Gilbert’s Potoroo has been identified as being particularly vulnerable to these changes in local climate ( Gilfillan et al, 2009) . Research in north Queensland on the impact of a drying climate on the availability of truffle like fungi in the habitat of the northern Bettong, Bettongia tropica, found that drought conditions led to a decrease in the availability of truffles and contributed to the local extinction of several populations. As one of the two most highly fungi dependent mammals in the world, it is likely that climate change impacts that result in drier conditions, and hence reduced availability of truffles, will have a similar impact on Gilbert’s Potoroo, perhaps limiting the potential survival of existing populations, reducing the carrying capacity of current locations and reducing options for future translocation sites.

Lack of knowledge

Photo Dick Walker, design by GPAG

Gaps in knowledge about Gilbert’s Potoroo while not direct threatening processes in themselves, may impede recovery by limiting the development and implementation of the best management strategies.   The Gilbert’s Potoroo Recovery Plan (2016, p.11-12) lists the following examples of areas where additional research is needed:

  • habitat use within existing population sites (including post fire recolonization);
  • causes of mortality;
  • understanding the levels and diversity of mycorrhizal fungi in known habitats;
  • impact of climate change on abundance and diversity of mycorrhizal fungi;
  • understanding the genetic diversity of populations; and
  • threat mitigation levels for future translocations.

Gilbert's Potoroo Captive Colony

The captive colony:

Updated content coming soon

How you can help

What can you do to help save Gilbert’s Potoroo?

  • Learn more about Gilbert’s Potoroo and spread the word to family, friends and colleagues. Our Knowledge Base is a good starting point for further research and includes links to large range of resources including media releases, news items, recovery plans, action plans, publications and other relevant websites.
  • Join Gilbert's Potoroo Action Group (visit our Join Us page - for a membership form or use the form at the back of the latest Newsletter)
  • Participate in one of our fundraising events or undertake your own fundraising challenge through Edge Pledge
  • Organise your own fund raising activity for Gilbert's Potoroo.
  • Donate to Gilbert's Potoroo Action Group either through our Donate button at the top right of each page of this website or via an electronic funds transfer
    (bank details can be found at the back of the newsletter)

If you think you may have seen a Gilbert's Potoroo, or found animal remains which you think could be a Gilbert's Potoroo, please check our sightings page which gives guidance on distinguishing Potoroos from similar animals and complete the online sighting report; alternatively, you can note down the sighting details as listed on the page and email to us at sightings@potoroo.org.  If at all possible include one or more photographs of the animal to aid with identification.