What ancient giant sharks can teach us about recovering Australian arid zone mammals

Admin Aridrecovery - Friday, April 07, 2017

The ancestors of whales first entered the seas around 50 million years ago, and quite frankly looked ridiculous (see a great video here). They had the mammalian blueprint, and appeared quite clumsy at first. After 20 million years, they evolved into a handful of species. They altered the mammalian design to become more sea-worthy, with their nose behind the head and no more useless feet. Although they were smaller and slower than modern whales, they were still larger than any other predator in the ocean, so they essentially had the place to themselves.

All those whales swimming through the ocean presented a lucrative prey source for a predator to exploit. Soon enough, one species of shark evolved with an effective, yet crude, way of hunting these whales. They grew big enough to attack them.

This shark is called Megalodon, Carcharodon megalodon, and was at least 15m long.


The terrifying Megalodon, Carcharodon megalodon. At over 15 meters long, it was a specialised whale killer. But this predator ultimately had a positive effect on whales, and forced them to become stronger and more diverse. Illustration by Elia Pritle


Considering this shark was the size of a bus, hunting the small, slow whales of that era did not need to be complicated. Megalodons simply ripped off flippers, crushed lungs, or took huge bites from the whales’ sides and waited for them to die. Many of these ancient whales would have become endangered by the predation pressure of this giant shark. Just as in the present day Australian landscape where cats and foxes have been introduced, an entire faunal assemblage found itself suddenly unequipped to deal with a new and vicious predator.

Despite the terror, the Megalodon shark ultimately had a monumental influence on whale evolution. Whales diversified like crazy, and went from what was likely around 6 species to over 20. They became faster, larger and started living and working packs. And they possibly started spending more time in areas Megalodon seemed to avoid, like the polar seas. Ultimately, these ancestral whales became like the whales we know today.

The sharks couldn’t keep up with the speed of evolutionary change in the whales. Their main advantage was their size, but the constraints of the fish blueprint meant they couldn’t evolve to be much larger or faster. Fish hearts are not as effective as mammalian hearts. To get any bigger than the Megalodon, a shark heart simply could not develop to the calibre required to pump blood around the whole enormous body and still move at speed. 

Eventually, the Megalodon ate all the slow moving whales to extinction, and were unable to hunt the better adapted whales of the new era (see here). They lost their primary food source, and went extinct around 2.6 million years ago (see here).


The Megalodon lost.


As far as the whales are concerned, it all worked out for the best. Though countless whales would have died terrible deaths to these brutal predators and species went extinct, as a collective they evolved and won. They adapted, overcame the threat, and ruled the oceans again until humans with harpoons came along a few million years later.

A similar event is occurring in Australia’s arid zone. Until recently, we had a diverse range of native mammals including bilbies, bettongs and stick-nest rats. New predators, the feral cat and red fox, have swept across the country, and most natives did not have effective strategies for dealing with them.

Feral cats have come to Australia and, like the Megalodon sharks, decimated the unadapted mammals like the above Plains Mouse. Can our natives become stronger like the whales did? Photo by Zac Richardson

Unlike the Megalodon versus Whale arms race that occurred over millions of years, the cats and native marsupials have co-occurred together over a mere 200 years at most. This is not enough time for the native animals to slowly evolve avoidance strategies or to develop new physical adaptations. Not only that, the arid zone has been besieged by many other changes such as rabbit plagues, intense cattle and sheep grazing,  and humans hunting with guns. Many of these species have gone extinct as a result.

But the other difference between the ‘Shark vs Whale’ and the ‘Cat vs Marsupial’ stories is that humans are now managing the landscape. We have the ability to jump on Wikipedia and Google Scholar to learn from the ancient whale story! All known knowledge of evolutionary history is available to us, and we can jump in and play referees for a fair and balanced arms race.

At Arid Recovery, our hope is that one day introduced predators and natives can coexist. Like the ancient whales, we know some species may be doomed to persist only on predator-free islands or in reserves. But for others, there is still hope for them to adapt and diversify. We need to find an equilibrium where the threat of feral cats and foxes is low enough to allow some natives to survive and adapt.



Native mammals like the burrowing bettong will hopefully learn to survive in a feral cat infested landscape. Photo by Nathan Beerkens


If we don't take action, will evolution take its own course? Can natives adapt as the whales did? Without conservation management, probably not. Cat and fox densities in Australia are being artificially supplemented. This is both from animals living in towns moving out to the wild (cats), and from the abundance of introduced prey species. For example, plague rabbits can increase cat and fox densities almost 10-fold. I doubt the ancient whales would have survived if they were dealing with 10 times as many Megalodons prowling the oceans.

Using the fences at Arid Recovery, we have been taking the next step forward in preparing native animals for co-existence with introduced predators. In two of our compartments, we add predators to a predetermined threshold, and hope to nudge evolution along in the right direction. By exposing native animals to feral cats, we can encourage natural selection to run its course in a controlled environment, and facilitate the evolution of traits that enable natives to co-exist with cats (read more).

While whales grew bigger and faster, what can we expect native mammals to do? Will they learn to build better burrows for protection? Become better at smelling whether cats are nearby? We can’t be sure, we hope that by setting cat predation at a controlled level, native animals will develop anti-predator traits (see here). The smarter animals, the faster animals, are likely to be rewarded so that the species is pushed to new heights.

In this vein, we’re pleased to announce the next stage of this research. Arid Recovery is partnered with the University of NSW and Bush Heritage through an ARC Linkage project that kicks off again this year. Hopefully, just as the ancient whales did, some of our native arid zone mammals can adapt to this new predator and forge a new future.

Written by Dr Hugh McGregor and Dr Katherine Tuft


Annual Trapping 2017

Admin Aridrecovery - Monday, March 27, 2017
Intern Emily Gregg describes the 2017 annual trapping event in this photo blog.


Only a few weeks ago the Arid Recovery lab was bustling with activity. Our annual pitfall trapping was underway and the reserve was swarming with staff and volunteers, all working to collect and process a host of native critters.


Some animals caught during annual trapping: Smooth Knob-tailed Gecko, Beaked Gecko, Stripe-faced Dunnart, and Painted Dragon (Photos by Ryan Francis)

On Saturday the 4th of March, the team set about digging out trenches and putting up the low fence-line running along the pitfall traps. Thanks to previous work by Arid Recovery staff, the Community Development Program and the Port Augusta Prison Work Camp, the pitfall traps themselves were already dug out, making our job that much easier.


Mel and her team digging out trenches and setting up pitfall lines. (Photos by Tony Pitt)


Once opened, the traps were checked at dawn and dusk, and each animal was placed in a catch bag and taken back to the lab for processing. Each animal was then released back to the same site the following day.


Mel’s team checking traps, featuring a newly captured Dunnart, some Plains Mice and a Broad-banded sand-swimmer in a pitfall trap (Photos by Melissa Jensen and Nathan Beerkens)


Our annual pitfall surveys give us the opportunity to get a grasp of the abundance and diversity of the small mammals and reptiles living within the reserve. They also provide a chance to compare populations inside and outside the fence, and see whether certain animals are doing better without the threat of feral predators.


Processing animals in the lab, featuring a baby Gibber Earless Dragon, a Plains Mouse, Beaked Gecko, and Barking Gecko
(Photos by Melissa Jensen and Emily Gregg)


This was an impressive year, with the team catching 778 animals in total! This number included a whopping 420 reptiles, and 358 mammals. This increase may be partially due to our altered trapping method; this year we replaced Elliot traps with an additional pitfall line at each site.

This year we also collected invertebrates during trapping. These insects and arthropods are being sent to La Trobe University for identification, in order to investigate the diversity of invertebrate species inside and outside the reserve.


Hopping Mouse, Western Barred Bandicoot, and Plains Mouse (Photos by Ryan Francis)


As explained in Kath’s last blog, the Plains Mouse (Pseudomys australis) is doing incredibly well within the reserve. This year we caught 236 of them! Of these, almost all were found within the reserve, with only eight found outside. It’s a similar story for the Spinifex Hopping Mouse (Notomys alexis), another species which the team saw a lot of over the course of trapping. A bonus mammal catch this year was a juvenile Western Barred Bandicoot (Perameles bougainville), found within the Main exclosure by Katherine Moseby’s team.


Thank you to all the volunteers involved this year. This annual survey would not be able to occur without your help and enthusiasm!


Education Centre to be built at Arid Recovery

Admin Aridrecovery - Friday, March 24, 2017


We’re delighted to announce that this year we’ll be building an Education Centre at the Reserve.


In January we applied through Fund My Idea and got busy on social media to encourage the community to vote for our project. We were overwhelmed by the support and this Tuesday had word that we were one of the 2 top-voted projects. Arid Recovery will receive $15,000 from the State Government and a further contribution from BHP Billiton to make the Education Centre a reality. Congratulations also to Whyalla RSPCA for their successful project to upgrade emergency pet boarding facilities.


Buildings donated by Roxby Downs Caravan Park are moved into place, ready to be retrofitted into the Education Centre


The building will have a ‘Field Classroom’ for wildlife education activities indoors, between nature walks and spotlighting for native animals. There will also be a bunkroom for overnight camps, boosting the accommodation at the Reserve to 18 beds.


With the new Centre we will be able to host more and larger school groups, community groups and visitors. It will enable more people to get out to the reserve and have an encounter with animals they’re unlikely to see anywhere else.


The Centre will be built by retrofitting portable buildings donated by the Roxby Downs Caravan Park and moved into place by Toll. We’re ready to source materials from local businesses and the Rotary Clubs of Roxby Downs and Frankston (VIC) are enthusiastic to support the build with their team of tradies.


Thanks to everyone who voted and supported this project. We look forward to opening the new Education Centre by the end of the year.


The Education Centre will be a base for more students and visitors to have close encounters with desert wildlife that will make a lasting impression.


Build it and they will come

Admin Aridrecovery - Wednesday, March 01, 2017

Sometimes threatened species turn up on your doorstep. Kath Tuft describes how Plains Mice reintroduced themselves to Arid Recovery.


As anyone who has ever assisted a species reintroduction program will know, it’s a heckload of effort. Detailed translocation proposals and ethics applications need to be prepared. Animals have to be captured and transported from source populations, often on remote islands. Animals must be fitted with radiocollars and then intensely monitored for many months following reintroduction. All of this can take years, thousands of staff and volunteer hours, and big bucks (Moseby et al. 2011).

Nicki Munro and John Read release one of the first bilbies into Arid Recovery.


We had an incredible instance where a threatened species turned up of its own accord without anyone lifting a finger. This was the Plains Mouse, Pseudomys australis, a beautiful little native mouse from arid Australia.

Plains Mice were once widespread across large parts of inland Australia. Now their distribution is greatly shrunken and their occurrence almost entirely confined to a specific cracking clay habitat with characteristic depressions known as gilgais (Brandle et al. 1999). Plains Mice persist in parts of far northern South Australia, but had never been recorded near Roxby Downs and the Arid Recovery Reserve until 2006.

A young Plains Mouse. Photo: Helen Crisp


That was the year I first came to Arid Recovery as a volunteer on the annual vertebrate trapping survey. To everyone’s surprise, a unique rodent with a Roman nose and short tail turned up at a trapping site within the Northern Expansion. It turned out to be one of the first Plains Mice recorded in the area for many decades.

When the main trapping survey had ended I was tasked with finding out more about these new arrivals. Were there more? What habitats were they occurring in? What burrows were they using? I had a great time trapping about the place and surveying for burrows. To find their burrows we lightly glued tiny glow sticks to fur on their backs and followed them as they bounced off with their little beacon. At that time, the Plains Mice were confined to a fairly small area of the cracking clay and gilgai habitat they are known for.

Me trapping Plains Mice 11 years ago. Photo: Hugh McGregor


Coming back to Arid Recovery 10 years later the situation is entirely different. There are Plains Mice absolutely everywhere. You can’t drive anywhere without seeing them scampering across the track. Where once they were confined to the classic cracking clay areas, they now occupy all habitats within the reserve: dunes, stony swales and canegrass swamps. The first Plains Mice to colonise the reserve very quickly found they were onto a good thing with no feral cats and foxes to prey on them. With that predation pressure relieved, they happily occupied the whole place in abundance.

Map of Plains Mice records in 2006 (left) and in 2016 (right). From one corner of the reserve, they have spread across the entire place in all habitats.


How did they find Arid Recovery in the first place? Plains Mice were known from areas several hundred kilometres further north near Lake Eyre, but not as far south as Roxby Downs. The likely answer is that Plains Mice were given a lucky break by the release of calicivirus, Australia’s first rabbit biocontrol. Calici swept through the rabbit population in the late 1990’s. The huge drop in rabbit numbers seemed to lead to a substantial reduction in the numbers of feral cats and foxes. Plains Mice, and other small native mammals, expanded in range as a result (Pedler et al. 2016).

What’s particularly neat about the Plains Mice at Arid Recovery, is that they might now be re-seeding the surrounding landscape. Trapping over the last few years has found them in good numbers outside the Reserve.


Abundance of Plains Mice at trapping sites inside and outside the reserve over time.


The resourceful Plains Mouse did all the hard work of reintroducing itself into the haven that is Arid Recovery. Hopefully in time we will see them disperse and re-establish well beyond the Reserve itself. These little rodents have shown that predator-proof fenced reserves can have value well beyond their core purpose of protecting reintroduced critical weight range species.

We eagerly await the next endangered species to show up on our doorstep and find sanctuary.


Reporting on failures

Admin Aridrecovery - Tuesday, February 07, 2017

Arid Recovery’s commitment to sharing all research outcomes for everyone to learn from


Arid Recovery’s ambitious goal is to see vulnerable native animals restored to Australia’s vast open landscapes, out of fences and roaming freely. To make any headway in this ambition it is essential to try new things, but this of course comes with risks. As is to be expected, we don’t always get the outcomes we want. Frequently when we try an idea it will fail. Over the last 20 years we have tested methods for establishing native animals outside of fences and found, that introduced cats and foxes usually overcome our efforts.

One of Arid Recovery’s objectives is to strive to publish everything: the good, the bad and the ugly. As we measure and monitor everything we do, these failures or setbacks are an opportunity to learn and further our understanding. We are not focused on good news stories, but on the only story that matters: what is actually happening.

We cannot hide from the fact that our conservation programs have led to animal deaths. Between 2006 and 2008 we ran the ‘Wild West’ project that was an attempt to establish a population of bilbies outside the reserve (read the paper). Enormous efforts went into feral cat and fox control with many hours put in by volunteers. We even tried training naïve bilbies to be wary of predators by exposing them to predator scents and models and associating them with an unpleasant experience. Despite our best efforts removing feral cats and foxes from quarterly aerial baiting, continual trapping and shooting, the attempt ultimately failed with the last bilby dying 19 months after release: a failure in most senses.






A bilby killed by a feral predator


However, we learnt so much from this failure. We now know that broad feral cat control is not necessarily that effective, but that targeted removal of individual killer cats may be. We learnt that training bilbies with scents and models of predators is no substitute for the real thing. These lessons are published in scientific journals, and have clearly shown us what we needed to do next. The experience led to our current project on Tackling Prey Naivety in collaboration with the University of NSW (and more here). Already there is success building on the foundation of the earlier failures.  We now have bilbies (and bettongs) coexisting with a low density population of cats.

There are other complexities and unexpected lessons learnt along the way too. The good news story of booming populations of threatened species reintroduced into the predator-proof reserve is not so simple. Our greatest success – returning some vulnerable mammals otherwise extinct on the mainland such as the Burrowing Bettong – has had a setback. Bettong numbers are now too high, damaging the condition of the vegetation in the reserve and reducing the food available for other species. Once again, by recognising the problem, analysing it, and not shying away from bad stories, we have been able to begin developing solutions. Currently we are testing one-way gates as a means for bettongs to disperse and relieve the pressure on the reserve, along with other options. Our commitment is that if this doesn’t work, we will still publish what we learn for the benefit of everyone.

Will these stories that are sometimes unsavoury cost us? It could taint our image in some people’s minds and could expose us to sound-bite criticisms from oversimplified media. But we believe this openness is critical to moving conservation forward in Australia.

We recognise that many organisations cannot often afford to stray from the good news stories to the same extent as we can by admitting the occasional failure. Politicians and public servants understandably wish to prevent government departments from being accused of ‘failing’ or ‘wasting tax dollars’, and big charities can ill afford to appear to ‘waste’ generous donations. This is in large part why so many insights and so much valuable information continue to lie in internal reports. It is an understandable waste, but a waste nonetheless.

We are optimistic that, collectively, we will eventually meet our goal of restoring lost mammals to Australia’s arid interior. One day, this battle may be over. Natives, cats and rabbits will, we hope, coexist with minimal intervention. To get there we need to build on our understanding of how arid ecosystems work and develop new methods for dealing with threats. Only by testing every assumption, by analysing every mistake, and by boldly trying risky ideas can we push our knowledge forward. To this end, we aim to publish papers on every one of our failures. By learning from these failures, not only we but also everyone else pushing conservation forward can gain some real ground.

Western Quolls suited to life at Arid Recovery

Admin Aridrecovery - Tuesday, January 31, 2017

Luke Tilley followed the trial reintroduction of Quolls to Arid Recovery to see where quolls sheltered, what they ate and what habitat they used.

by Luke Tilley (Honours student, University of Adelaide)


We know that the Arid Recovery Reserve is a suitable place for Western Quolls to breed and raise young. Although these two youngsters were a month off independence when their mother died, they survived on their own for 10 days before being taken into care. They have since been released into the Flinders Ranges to boost the quoll population there. Photo credit: Gini Andersen


Arid Recovery is working towards reintroducing Western Quolls to the arid outback of South Australia. Quolls are large marsupial predators that once played an important role in the ecosystem. My honours project involved looking at the shelter use, habitat use and diet of the four Western Quolls reintroduced to the Arid Recovery Reserve throughout 2015 and 2016. I also looked at the potential impacts of a full scale quoll reintroduction on the populations of in situ species, including the overabundant Burrowing Bettong. It has been well documented that within the Reserve, bettongs are overbrowsing vegetation, resulting in a significantly negative effect on cover and structure.

I found that quolls used bettong warrens and single entrance burrows almost exclusively for day time shelter over the nests of Greater Stick-nest Rats. Only one nest was found to be utilised for shelter by a quoll. They selected dune habitat over swale and swamp habitats for night time foraging, and sheltered almost exclusively in dune habitats.

A total of 74 scat samples were collected and analysed. Scats contained Burrowing Bettong, Western-barred Bandicoot, native rodents (plains rats and hopping mice), Greater Stick-nest Rat and other prey items (invertebrates, skinks etc). Greater Bilby was not detected in any of the scats analysed. Quolls ate rodents in the same proportion as they were available in the reserve. They ate fewer Bettongs, Bandicoots or Stick-nest Rats than would be expected if they were hunting according to what was available, indicating that they mostly hunt smaller prey but may take larger species like bettongs when they are juveniles.


Frequency of prey items in Western Quoll scats compared to track counts

Quolls did not show any strong preference for hunting one prey species over another, suggesting they may not pose a threat to some of the more vulnerable less abundant reintroduced species such as Stick-nest Rats. However, it's hard to be certain what the population-level impact might be of a full-scale quoll introduction on other species so they will need to be monitored closely when a reintroduction goes ahead.

Quolls have the potential to be a predator of bettongs and help to regulate their population. However, we suspect that other management strategies, such as one-way gates, will need to be used in conjunction with a full quoll reintroduction for quolls to be effective ecosystem regulators.


Quoll reintroduction set for 2018

The great work of Katherine Moseby, Bec West and Luke Tilley in trialing a Western Quoll introduction has shown us that it can be done, and taught us some valuable lessons (e.g. some quolls can and will climb out of the fence and head off). We’re working towards a full reintroduction of quolls to happen in early 2018. This gives us extra time for quolls in the Flinders Ranges, WA and captivity to breed up so we can have a full contingent of new spotty predators to bring back to the arid zone.


One of the most unique Green Army Projects in Australia

Admin Aridrecovery - Wednesday, January 11, 2017
Few young people (aged 17-24) in Australia have the opportunity to get so close to the running and management of a world class conservation, research and education facility such as the Arid Recovery Reserve (our Project Partner). The wisdom and inclusiveness of Arid Recovery staff and their allies over the past 20-weeks has provided experiences our Participants will be able to use and reflect on in both their professional and personal lives. The Green Army is an Australian Government initiative which provides opportunities for Participants to work on local community and conservation projects, while gaining skills and training that can help them enter the workforce or improve their career pathways. 


An early morning of bilby trapping and processing with researcher Lisa Steindler. All photos credited to: Adrian Friedel

The work we have carried out at the Reserve falls into two broad categories: infrastructure maintenance, and science and research. Fence upkeep is integral to the Reserve’s success and ‘feral-free’ mantra. A large focus of this Project was replacing footnetting in areas where the integrity of the original skirt was starting to fail (through rusting and chemical breakdown). In some cases we used reclaimed netting from decommissioned pastoral fences within the reserve, to reduce pressure on a stretched budget. We also foot-netted the western fenceline of the 2nd Expansion, an area which was once used as a control, but now supports burrowing residents from the surrounding exclosures. 


All in a days work - Fencing is an integral part of Arid Recovery. 

The last few weeks of our Project included conducting vegetation monitoring using a quadrat-based method to quantify the impact of particularly bettongs on vegetation species inside the Reserve (using a selection of sites outside the Reserve for comparison). This replicates adds to a study first conducted in 2013. Given that current bettong populations are considered a little on the high side, we expect a marked contrast in plant condition. 

My team has also enjoyed participating in community activities such as regular market days, the Arid Recovery Quiz night and Christmas pageant. Together with contributions to the online presence of the Reserve (through blog and photo submissions), this has provided an insight into the importance integrated community involvement in maintaining the regional profile of the Reserve. The team also had the chance to visit Bon Bon Reserve to assist with wombat warren monitoring and maintenance tasks. 

Having the opportunity to get up close and personal to the unique wildlife of Arid Recovery lists as another highlight, and we are grateful for the generosity of visiting (and resident) researchers in incorporating the Green Army with some of their catching and processing activities.


The team regularly assisted at community events and fundraisers.

Written by Adrian Friedel, Round 2 Green Army Supervisor

Testing a simple solution to over-abundance

Kimberley Solly - Tuesday, December 20, 2016

This study not only looked at the number of Burrowing Bettongs to leave the Arid Recovery Reserve but also the number of bettongs investigating the gates, the influence of gate placement, how to optimise gate use via a food lure, the sex ratio of departing bettongs and also the distance travelled by a bettong to access the gate. Bettongs were cage trapped as they exited the gate to see if there was a bias in the animals that were using the gates. Also, radio collars were affixed to some bettongs before releasing them back into the Reserve in order to record the distance a bettong travelled to access a gate from their home territory.  

Baiting the gates with peanut butter and oats as well as the landform placement (swale vs dune) both had effects on the use of the gates by the bettongs. Baiting increased the visits to the gate as well as the exits from the gate. Additionally, placing gates in dunes or corners of the fence rather than on interdunal swales also increased the visits to the gates. There was no difference in the number of males or females using the gates to exit the Reserve. The movements from the gate to the bettong’s burrow were wide ranging between 75m and 1.5km with an average of 418m. 


a) Curious bettongs investigating a one-way gate b) A bettong entering a one-way gate c) A bettong exiting on the other side. Photo Credit: Kate Butler

The optimal configuration for a gate was to be installed on a dune and baited with peanut butter and oats. In this configuration approximately one bettong, on average, exited per gate per night. No incursions by bettongs or feral animals into the Reserve through the one-way gates were recorded suggesting that the gates are working effectively in restricting traffic to one-way. The results presented in this study suggest that there is great potential for one-way gates to be implemented as an effective method of managing the over-abundance of Burrowing Bettongs at Arid Recovery. 

One-way gates will reduce the costs and labour involved with other management techniques such as relocation of animals and will negate the need to cull an endangered species. A combination of techniques may be needed to successfully reduce the population to a capacity that the Arid Recovery Reserve can sustain. 

Written by Kate Butler, Honours Student, The University of Adelaide

20 years of cat control: keeping threatened species safe

Admin Aridrecovery - Monday, December 19, 2016


Buoyed after another successful week of cat control, Field and Maintenance Officer John Crompton and our dedicated volunteer shooters removed 13 cats and 4 foxes in one week. Each of the cats had between 1 and 5 native mice in their stomachs, including the threatened Plains Mouse. It is sobering to think of just how many animals these cats are killing every night, but we’re glad our feral predator control is making a difference.

Our feral predator control is partly about making a safe haven around the perimeter of the Arid Recovery fence, but also helps to keep cats and foxes out of the Reserve. Our fence is designed to be cat and fox proof, but we have to ensure there are no incursions of feral animals from damage to the fence.

Our floppy-top fence design is an extremely effective deterrent. Cats that attempt to breach the fence by pouncing on the floppy top are flung to the ground. But as everyone knows, feral cats are incredibly intelligent. If given enough time, and presented with a reward as good as the defenceless native animals inside, they will instantly take advantage of any weak point.

Our fence is currently our best defence against feral animals. Photo Credit: Kimberley Solly

Just recently, the September storm that cut off power to South Australia, also blew the floppy top inwards along sections of our western boundary. Not long afterwards we found cat tracks inside the Reserve.

Over the last 19 years, a few individual cats have breeched the fence like this. Removing them has been a herculean effort. It’s one thing to remove one cat of many in an open landscape, but to seek out and remove one lone cat in a sea of native animals is something else altogether. Great care must be taken when using traps and shooting. Usually the whole Arid Recovery team and volunteer community have to hunt intensively for months on end.

So our feral predator control strategy is to remove cats before they have time to study the fence for weaknesses. To this end, we created a permanent set of cat traps along the outside perimeter of the fence. To draw cats in, we have tried every lure imaginable: fish oil, cat urine piss and sound players that make meowing sounds. These typically catch between one and fives cats per week.

On top of these permanent traps, we also have a team of dedicated volunteer shooters. Feral control not only reduces the risk of incursion, it also creates a buffer zone protecting native animals around the perimeter of the reserve.  Some volunteer shooters have removed over 50 cats and foxes for us. No doubt many of the bilbies and bettongs of Arid Recovery owe their lives to their efforts.

John Crompton our Field and Maintenance Officer patrols the fence and permanent trap sites. Photo Credit: Charmayne Cronje

Unfortunately, no matter how much cat control we do, we will never eradicate cats from this region. There will always be new cats to wander in from elsewhere; whether they are strays from towns or ferals from far far away. But thanks to the rigours and dedicated efforts of staff and volunteers, we have at least kept their numbers lower than they would have been otherwise around the fence.

Our trapping and shooting efforts are not about hating cats and foxes, but about loving our native wildlife and doing everything possible to keep their populations strong. Please support our work managing the threat of feral cats at Arid Recovery. There are many ways you can get involved: you can volunteer, become a Friend of Arid Recovery, come out on a spotlighting tour, join one of our community events or support our work by donating or adopting a bettong or bilby.

Written By Hugh McGregor, in partnership with the University of Tasmania and National Environment Science Programme. 




Seed Predation Paradigm Shifts in Australia

Admin Aridrecovery - Monday, November 14, 2016

Animals which specialise in eating seeds are known as seed predators. In the desert, their preferences for specific species of seeds can change the number and types of plants in an area by removing seeds from the bank they grow from.

In many countries mammals are the main seed predators, followed by ants then birds. In Australia, ants are considered the most important seed predators, and mammals are considered unimportant. The role of Australian mammals as seed predators is largely unknown because they were lost before we understood how they interacted with seeds, plants and soils. Our understanding of seed predation in Australia was therefore built in areas which are devoid of native mammals.

Now these mammals, once common around Australia, are only present in places like small islands or in secure fenced reserves. The recent establishment of strong populations in fenced reserves provides the opportunity to question their role as seed predators.

At the same time that native mammals declined, Australian desert landscapes became dominated by weedy shrub species and grasslands declined. This phenomenon, known as shrub encroachment, is a symptom of land degradation. There is no known seed predator for weedy shrub species, although they mostly grow in areas that lack mammals.


Shrub encroachment. On the right hand side of this fence you can see many more shrubs. On the left side, much more grass (grey patches). Interestingly, we find lots of small mammals on the left, but none on the right.

I studied seed predation in native mammal reserves, including Arid Recovery, to determine if Australian mammals are important seed predators, especially of weedy shrub species. I placed trays of weedy shrub seeds inside reserves where mammals are common and outside where mammals are rare. After two days I counted the number of seeds left in the trays. I used tracks at the trays and photos taken by motion sensing cameras to determine which animals were eating the seeds.

Native mammals were the main predators of weedy shrub seeds and ate many more seeds than ants. The main seed predators inside the reserves were native hopping mice and the Burrowing Bettong, a small rabbit-sized marsupial closely related to kangaroos. 


A burrowing bettong (Bettongia lesueur). Burrowing bettongs were once common on the mainland and are now only found in fenced reserves or small islands. Photo credit Nick Tong.

My research indicates that paradigms on seed predation in Australia should be reconsidered to include mammals. I found that native mammals are important seed predators in Australia, and their decline may have contributed to shrub encroachment. This research demonstrates that projects aimed at restoring Australian native mammals may provide unexpected benefits such as natural weed control.

Written by Charlotte Mills, PhD candidate, Centre for Ecosystem Science, UNSW.

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Stickie Haven to go ahead
30 Nov, 2017
Stickie Haven to go ahead We put the Greater Stick-nest Rat (http://www.aridrecovery.org.au/greater-stick-nest-rat) in the spotlight  .. ..
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Arid recovery is a conservation initiative supported by:
bhp
adelaide university