Really gang, you are becoming so boringly predictable and need to come up with something honest.
Aries54,
Really ? So, why not change the same old boring tune of presentation ? How about presenting alternatives ? How about not keeping on telling people what hey don't want to hear anyway ?
Tell people how they can have a decent living without pollution & environmental degradation ?
How about showing us solutions to over-population & excess greed ?
If the ABC does that they'll have a very captive audience who doesn't feel their tax dollars are wasted !

Garry in Liffey

"....the Conservation Advice …. mentioned increased sightings and raised these in the context of new techniques being used. I believe the conservation advice made the point that the increase in sightings was not necessarily indicative of an increase in populations, but rather was possibly a function of the newer techniques being better able to locate individuals/colonies which, when the ‘older’ techniques were being used, had been going ‘under the radar’".

Yes, I don't disagree. However, the TSSC has continued to rely on the past data from the using the less effective survey technique on approximately 30 long-term monitoring plots. This data shows a decline in possum occupancy, but Vic Govt scientists using the new techniques have since used the new technique on these same plots and found the possum to be still present. The TSSC was provided with this information but have ignored it. Also, the new survey technique is showing that the possum was never particularly rare, and this suggests that the controversy surrounding the supposed impact on it of logging and regenerating forests should never have happened.

" ….it seems counter-intuitive to conclude populations are increasing while the number of hollow-bearing trees is decreasing".

Yes, except that it seems now that the possum is more resilient and widespread, and that it is able to live in areas where it was never thought able to. The TSSC has exaggerated the rate of hollow tree loss by adopting a worst-case assumption that 50% of the mountain ash forests will be burnt in the next 20 years, and then wrongly presuming that fire represents a total loss of hollows. It is these extreme assumptions that enable the possum to be listed as critically endangered.

I’m not sure that I understand you correctly, Mark (18July, 10:17:18). Your...

“...the TSSC has continued to rely on the past data from the using the less effective survey technique on approximately 30 long-term monitoring plots. This data shows a decline in possum occupancy, but Vic Govt scientists using the new techniques have since used the new technique on these same plots and found the possum to be still present. ”

...seems to be a simple restatement of what I’d written, and I don’t understand how the repetition advances things. And to state that…

“The TSSC was provided with this information but have ignored it.”

… seems incorrect. The TSSC included this information in their advice [ https://tinyurl.com/y2ecrnbw ] and I also referred to that inclusion with my ‘under the radar’ comment.

/...

.../
I did share you view that a 50% burn out in the next 20 years seemed a big figure. However, I’m not sure whether calling it ‘exaggerated’ is justified - the advice does explain its use of that figure and gives the 50% figure as a ‘worst case scenario’ in a range of 20-50% burn-out. The relevant Conservation Advice on Criterion 1A3(b) (to do with potential habitat) draws on papers Baker et al. (2017) and Lindenmayer & Sato (2018). The advice concludes that under that criterion, the possum is endangered and may be eligible for listing in the critically endangered category.

The listing as ‘critically endangered’ comes from another criterion: 1A4(b) – and has to do with the available habitat / number of hollow bearing trees.

Both criteria make use of that 50% fire estimate regarding possible reduction of potential/available habitat. The Conservation Advice doc (p. 13) give three reasons why the 50% figure projection of areas burnt should be used: the areas burnt in 1939 can be used as a guide to the probability of future fire, extreme fire weather will increase over the next three generations and beyond and the possum’s forest habitat area is in a state of regrowth and thus is in a state of elevated flammability.

Regarding 1A4(c) the Conservation Advice document notes that IUCN guidance regarding the moving window of three generations is that “the particular window should be chosen to provide the maximum estimate of reduction.” The Advice, in my view, is reasoned and references a variety of what seem to be relevant studies.