Choice of site/area

The best case scenario for ringtail conservation would be provided in an area comparable to Locke Estate Nature Reserve/Campsite area in Busselton.
Extensive, protected areas with alluvial soils, mature trees with a greater chance of possessing hollows for shelter/protection and larger peppermint trees providing nutritious foliage are extremely rare in the core habitat area for the western ringtail possum, which is under immense development pressure. This area has also been left unburnt for several decades and is continuously fox-baited.
However, disturbingly the only population viability analysis (PVA) we have so far was conducted in this habitat and the modelling revealed a 93% extinction risk in a 20-year time frame. (Yokochi, 2015)

As the number of palatable trees, in other words the quality and quantity of food resources, determine the carrying capacity of an area (Pahl, 1987), large viable ringtail colonies such as those still inhabiting the core habitat will most likely become a thing of the past soon. Patchy, low-density populations across the most southerly parts of the range will be the new normal.
Due to the changing environment and in particular the changing climate it can be expected that the species will contract southwards. (Jones et al, 2007)

However, with climate change, jarrah and marri, the other main food sources, are predicted to experience similar contractions in range as peppermint according to Molloy all throughout the ringtails’ range. Populations outside their core habitat may increase in importance and might provide the best potential conservation opportunities. (Molloy et al, 2014)

The most often cited factors for western ringtail possum translocation failures are poor foliage nutrient quality, predation and competition with common brushtail possums. (Clarke, 2011)

Protection and enhancement of existing core habitat by emphasising retention of all ‘used’ habitat trees and increased plantings of peppermint trees and other food sources, nutrient enhancement of trees and irrigation of new plantings and established trees in summer and possibly even in dry winters would seem the most cost efficient way of saving the species.
Unfortunately in reality western ringtail possum habitat is instead constantly destroyed and eroded by all types of land managers. (see: 'Habitat discussion')

All translocations to sites in which predators are present can be expected to suffer losses especially in the establishment phase.
Even fenced sites that exclude introduced predators will not be mortality free but they would at least be far safer particularly for naïve hand-reared animals.
If sanctuary style areas were available and animals should not only establish but breed well, those refuges could also provide source animals as future colony founders.
No breeding program could ever be as efficient as ringtails breeding in an optimal environment. However, there seems to be no inclination so far to investigate the possible establishment of a western ringtail possum sanctuary in the core habitat area as it would be considered too expensive, logistically difficult and in some areas even unpopular with the general public. (Clarke, 2011, pers. comm. AWC)

Private property fencing projects would struggle with eligibility criteria for grants and would be unaffordable for most willing landowners anyway. Habitat quality would need to be assessed professionally which could incur high laboratory costs. Surveys of native predators and subsequently their professional eradication would also be far outside the financial scope of landowners or any community group.

In official translocation research survivorship of translocated western ringtail possums was strongly negatively influenced by large numbers of common brushtail possums.
Finding a place to establish successfully is always a major challenge post-release, especially if the area is already occupied by conspecifics or other species filling a similar niche such as common brushtail possums. However, all we can ethically do is to search for areas with no brushtails or only in low numbers. 

Ringtail releases through community members are heavily criticised by the relevant department, even if they do not have a translocation program in place and would therefore be unable to release the animals in an orderly way themselves. 
When asking for conditions the department wanted to see us meet the list as follows:

In principle I agree with those conditions, however finding truly suitable sites proves difficult as they are likely to already contain populations of the species.
As departmental staff is rarely able to evaluate habitat values and in particular identify food suitability, this can hardly be expected from untrained community people.

If there should be an immediate corridor connection to bushland the same department demanding it would most likely also demand it to be cleared as a firebreak around the property.

The department encourages predator control on covenanted properties but does not even enforce it there. In this light, it surly cannot be made a condition for landowners willing to give ringtail possums a home.

Surveys and counts of animals present are usually conducted as a condition for the approval process for development or as part of a funded research project. If untrained community people conduct a survey it will not provide more than a superficial impression of what is present.  It is also unrealistic to expect permission from landowners to spend several nights trampling through their bush.
An impression of very low density can just be the result of a badly chosen survey night. To account for those, the rule is to survey on 3 non-consecutive nights, which again is highly unrealistic when wanting to release on a 100 ha property.

Densities in official translocation sites (Yalgorup National Park, Leschenault Peninsula) stayed low even after many years of translocation and in Yalgorup animals only persevered in pockets of high-connectivity peppermint-dominated habitat while the Leschenault populations is too low to survey.  (Clarke, 2011)
The reason for those low density populations could be the scarcity of food in the presence of predators, which would mean that the current low density might be the highest viable density for the area.
The same low carrying capacity due to food scarcity could apply to any of the release areas used by community groups and individuals.

Estimating occupancy without bias would also include a distinction between breeding females and - the other extreme - transient occupants which might be travelling through multiple sites while dispersing.

In my personal view scat searches often give a more reliable and easier to achieve impression of occupation than night spotlighting surveys.
Presence of brushtails is similarly difficult to quantify but it is easy to distinguish between the scats of the 2 species and one thorough scat survey could give insight in to both issues. 

Ideally, not only the proposed site, its current occupants and the perceived habitat quality and resulting carrying capacity would have to be considered, but also the dispersal propensity and probability of mortality for dispersers. The surrounding landscape, including connectivity, linkages and the wider predator management will become of concern if the colony is thriving.

I doubt that these considerations play a large role in the choice of conservation estates for western ringtail possum reintroductions by the relevant department, but they are clearly outside the scope of a community group or individual.

The demand for ‘keen landowners if possible’ is puzzling as this is an absolute conditio sine-qua-non.  
The landowners we work with are the backbone of every release. Without their acceptance of letting us use their property as if it was ours, without their willingness to tolerate whatever is deemed necessary for the welfare of their growing ringtail population, without their own involvement and watchfulness (as they are on-site while we are not) releases the way we conduct them would never be possible.
If the landowners agree to predator control that also adds a major work commitment. Baiting (I am not licensed), checking traps in the early morning and patrolling can only be done by people on-site. 

major threat: predation