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Bettongs fall prey to foxes in risky trial release

By John Thistleton - 24 January 2017 24

Caption: an eastern bettong asleep. Photo: ACT Government.

At least 11 rare eastern bettongs have died in a contentious trial release into the Lower Cotter Catchment that raises questions on use of land management resources.

Fifteen bettongs remain alive. Four have been confirmed as killed by foxes, one from a bird of prey, and forensic results are yet to determine other deaths.

One has been returned to captivity with a faulty collar, while another one could be in the wild with a faulty collar. The collars monitor the endangered species three times a week.

The ACT Government will not say how much additional money is being spent on intensive fox control.

Environment Minister Mick Gentleman has not answered questions on the trial. A spokesman says he is on leave.

Two years of intensive control preceded the release phases, which began last spring. A wider variety of baits are being put out as fox cubs leave their families and begin to hunt.

Critics say the trial is futile because foxes will never be eradicated from the bush.

An environment and planning department spokesman said establishing bettongs at Tidbinbilla Nature Reserve and Mulligans Flat Woodland Sanctuary allowed greater risks to help lift the conservation status of the entire species, and improvements in future releases.

He said bettongs had not lived on the mainland for 100 years, and information from the trial would answer whether they could survive in fox-controlled areas, or if they would disperse away from the release-site.

He said the Lower Cotter trial met International Union for Conservation of Nature guidelines.

“There is no specific target population for this trial release because the main objective is garnering information, not establishing a population. If a full reintroduction is considered feasible, the number of animals to be released – and required predator control – would be determined based on the results of the trial including the area’s carrying capacity.”

Was the ACT Government right to release rare eastern bettongs in the Lower Cotter Catchment?

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Attempts to reintroduce rare species in the ACT have divided conservationists.

One critic said the Mulligans Flat sanctuary was a glorified zoo, while another has slammed the bettongs release, and suspects between 5 and 10,000 bettongs would be needed across the Cotter Valley and beyond to establish a viable population.

“Intensive fox and cat control would be required forever over the whole of the area plus a buffer zone around the bettong-occupied area. This would be huge and prohibitively expensive and require many staff,” he said.

In the spring of 2009, 43 vulnerable brown treecreepers caught from an established community south east of Wagga Wagga were released at Mulligans Flat and neighbouring nature reserve Goorooyarroo.

Although the countryside had been fortified with dead timber and artificial shelter areas, it did not provide the little insect-eaters with as much cover as the landscape from where they had been caught. Consequently other bigger predators quickly had an easy meal.

In 2014, 11 bush stone-curlews were brought into Mulligans sanctuary from where six escaped and were either taken by predators, probably foxes, or left the area.

Last year eastern quolls arrived at Mulligans from Tasmania and a private breeder in Victoria. Seven of them wasted no time scaling the 1.8 metre high fence and escaping. Foxes killed four of them, after which the fence was to be retrofitted.

In 2015 University of Canberra researcher Dr Bruno de Oliveira Ferronato published findings of reptiles being caught in the fence enclosing Mulligans sanctuary.

Over 16 months he found 108 reptiles had died and more than 1000 animals blocked at the fence, with eastern long-necked turtles accounting for almost all deaths.

Pictured above, an eastern bettong asleep. Photo: ACT Government

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24 Responses to
Bettongs fall prey to foxes in risky trial release
wildturkeycanoe 6:31 pm 28 Jan 17

Steve Chivers said :

This was a “trial”, an experiment… gathering data before making a determined attempt at reintroduction. They likely wanted to gather data on predation and survival rates.

So, putting them in an area that isn’t suitable because of predators and future climate change, helps them get data on the success of introducing them into a completely different alpine area with a different concentration of predators, both native and introduced? They might as well have just put them in a giant blender and seen how many survive, the data would be just as useful.

Tadanus 3:42 pm 28 Jan 17

Steve Chivers said that do you really believe that the ANU scientists had not considered these maters before commencing the experiment. If they have please point me to the reports. I have listed a number of factors that should have been considered before releasing the animals. These are based on my knowledge of the translocation literature and the IUCN criteria for reintroductions. If the ANU scientists had undertaken a critical assessment of the study against the IUCN criteria and reviewed the relevant literature they would know that the chances of establishing a self sustaining wild colony of bettongs in the LCC is zilch. Just for example consider a Population Viability Assessment of the bettong population that would be required to withstand predation and other factors, The size of such a population, the area it would need to cover and the cost of extensive and ongoing predator control alone that would be required (but wouldn’t be sufficient as shown by numerous studies in peer reviewed journals) would be prohibitively expensive and impracticable. This alone would show the futility of the study. If you can post or point out that such an assessment had been done then I would appreciate it.

dungfungus 2:28 pm 28 Jan 17

Steve Chivers said :

wildturkeycanoe said :

I can not believe the “scientists” who ran this project couldn’t see this happening. There are foxes running around in the suburbs, so who knows how many are out in the fringes of Canberra. Releasing a defenseless little critter into areas that quite obviously contain large numbers of predators was always going to fail. Now they have to go and breed up a new batch of bettongs and try something else. Perhaps they are simply extending the duration of the project so that they have some job security, who knows. But any person with a bit of logic could’ve put money on this experiment failing. You may as well have dropped a spoon full of guppies into a bucket of pirhanas and seen the same result.

Do you really think the scientists didn’t foresee this happening? This was a “trial”, an experiment… gathering data before making a determined attempt at reintroduction. They likely wanted to gather data on predation and survival rates.

I’m surprised at the number of people who’ve read this minute media-release suddenly think they’re experts on wildlife re-introductions, having not even read any of the actual scientific reports by the bettong recovery team at ANU.

Why couldn’t they have used computer modelling instead?

It works for climate scientists.

Steve Chivers 9:27 am 28 Jan 17

wildturkeycanoe said :

I can not believe the “scientists” who ran this project couldn’t see this happening. There are foxes running around in the suburbs, so who knows how many are out in the fringes of Canberra. Releasing a defenseless little critter into areas that quite obviously contain large numbers of predators was always going to fail. Now they have to go and breed up a new batch of bettongs and try something else. Perhaps they are simply extending the duration of the project so that they have some job security, who knows. But any person with a bit of logic could’ve put money on this experiment failing. You may as well have dropped a spoon full of guppies into a bucket of pirhanas and seen the same result.

Do you really think the scientists didn’t foresee this happening? This was a “trial”, an experiment… gathering data before making a determined attempt at reintroduction. They likely wanted to gather data on predation and survival rates.

I’m surprised at the number of people who’ve read this minute media-release suddenly think they’re experts on wildlife re-introductions, having not even read any of the actual scientific reports by the bettong recovery team at ANU.

dungfungus 12:29 pm 27 Jan 17

wildturkeycanoe said :

Tadanus said :

. For example, bettongs feed on sub-surface fungi and invertebrates. These are certain to have declined as the soil became drier, a situation that will only get worse as global temperatures rise and effective rainfall declines.

So, why not try to reintroduce them to an area that is slightly higher in elevation and has the right climate for these little creatures? The lack of implementing an idea as simplistic as this astounds me. It’s like if your garden is not getting enough sun to grow tomatoes because you built a roof over it, why wouldn’t you plant them elsewhere in the yard that has ample light? Just like the fox problem, it isn’t rocket science, so how poorly is this government department run? I think they need some outside help, perhaps a local primary school?

That is great “thinking outside the square”.

Unless you are an “expert” (preferably from overseas), the agency will ignore your suggestions.

wildturkeycanoe 4:28 pm 26 Jan 17

Tadanus said :

. For example, bettongs feed on sub-surface fungi and invertebrates. These are certain to have declined as the soil became drier, a situation that will only get worse as global temperatures rise and effective rainfall declines.

So, why not try to reintroduce them to an area that is slightly higher in elevation and has the right climate for these little creatures? The lack of implementing an idea as simplistic as this astounds me. It’s like if your garden is not getting enough sun to grow tomatoes because you built a roof over it, why wouldn’t you plant them elsewhere in the yard that has ample light? Just like the fox problem, it isn’t rocket science, so how poorly is this government department run? I think they need some outside help, perhaps a local primary school?

Tadanus 1:27 pm 26 Jan 17

I note in the Canberra Times that a spokesperson for the ACT Parks and Conservation Service said that the trial is to learn more about the system for before establishing bettongs in the wild. From what I can see, the assumption is that foxes, dogs (read dingoes in the Cotter) and cats are the cause for the extinction of bettongs on mainland Australia. Just for a minute suppose that they are. It is not feasible or economically practical to control foxes, cats and dogs for the foreseeable future to the level necessary across the area that would be required to establish a viable population of bettongs in the ACT, as I said in my previous comment. Also, why control dogs/dingoes? I understood that ACT Parks considered them to be native and an important top order predator.
But worse, it is highly likely that other factors have led to the demise of bettongs on mainland Australia. Other peer reviewed studies in various parts of Australia have shown that fox control alone is not sufficient to conserve rare and endangered species. For example, while there was an initial recovery of native mammals from large-scale and intensive fox control over many years in areas such as Western Shield, Western Australia and Glenelg Ark, Victoria, despite intensive and long-term fox control, most mammals have returned to near pre-fox control levels. Also under the NSW Fox Threat Abatement Plan, only one program out of 20 that were aimed at conserving threatened species showed any recovery in response to intensive fox control. The one that did, the south coast shorebird recovery program, had some success because they addressed several factors such as suitable nesting habitat, tidal surge and predation by native predators, not just fox predation. It is very likely that other factors in addition to fox and cat predation have led to the loss of bettongs in the ACT. These are likely to be lack of suitable food and other resources, probably as a result of changed fire regimes and global warming as well as loss or degradation of habitat. For example, bettongs feed on sub-surface fungi and invertebrates. These are certain to have declined as the soil became drier, a situation that will only get worse as global temperatures rise and effective rainfall declines.
To justify the expense of the present study and the use and potential loss of such rare animals, it behoves scientists running the study first to identify all the factors that may explain and observation (loss of a species) and gather the available information to assess each cause. Those causes/factors that cannot be eliminated based on the available evidence need to be tested experimentally. This is the accepted basis of experimental design. I see no evidence that the current study is looking at factors other than predation.

dungfungus 5:55 pm 25 Jan 17

Roksteddy said :

dungfungus said :

“fox-controlled areas”?

No such things exist.

Do you mean apart from Mulligans Flat?

That is a fox-free area – different thing.

Roksteddy 3:59 pm 25 Jan 17

dungfungus said :

“fox-controlled areas”?

No such things exist.

Do you mean apart from Mulligans Flat?

dungfungus 12:17 pm 25 Jan 17

John Thistleton said :

My biggest problem with this trial is that it was never established in public. It came to light because someone blew the whistle to alert the wider Canberra community. We often see our ACT pollies with newly arrived rare native animals. I am still waiting to see one of them endorse this trial, which is being undertaken in an extremely prone bushfire zone….not to mention foxes.

Good points John.

I am waiting for the government to introduce more Rainbow Lorikeets to establish a resident population:
http://canberrabirds.org.au/birds/rainbow-lorikeet/

Then it could replace the less vibrant Gang Gang as the forna in our emblem.

John Thistleton 8:45 am 25 Jan 17

My biggest problem with this trial is that it was never established in public. It came to light because someone blew the whistle to alert the wider Canberra community. We often see our ACT pollies with newly arrived rare native animals. I am still waiting to see one of them endorse this trial, which is being undertaken in an extremely prone bushfire zone….not to mention foxes.

wildturkeycanoe 6:52 am 25 Jan 17

I can not believe the “scientists” who ran this project couldn’t see this happening. There are foxes running around in the suburbs, so who knows how many are out in the fringes of Canberra. Releasing a defenseless little critter into areas that quite obviously contain large numbers of predators was always going to fail. Now they have to go and breed up a new batch of bettongs and try something else. Perhaps they are simply extending the duration of the project so that they have some job security, who knows. But any person with a bit of logic could’ve put money on this experiment failing. You may as well have dropped a spoon full of guppies into a bucket of pirhanas and seen the same result.

Tadanus 6:03 pm 24 Jan 17

The article is correct. The wild bettong population would need to be in the thousands and spread over a large are for the wild population to survive the ravages of drought, bush fires and predation from foxes, cats and native predators. Trying to control foxes alone over such a large area – forever – would be impractical and hugely expensive. Also as the article reports, displaying animals in a fenced enclosure is difficult and expensive and not without significant deleterious impact to local native wildlife. Maybe worthwhile but it would be interesting to see a cost benefit analysis of the program as well as a risk analysis.

switch 1:24 pm 24 Jan 17

We need another poll: Which is more fun? Working with cute and cuddly bettongs or eradicating foxes? Easy to guess which way the poll would swing, but this trial does seem to be putting the cart before the horse.

dungfungus 8:48 am 24 Jan 17

“fox-controlled areas”?

No such things exist.

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