Know thy enemy - What happens when you breed animals in an environment where there are no predators?

Admin Aridrecovery - Tuesday, October 18, 2016

There have been a few blogs along the way regarding my research of the Greater Bilby (Macrotis lagotis) at Arid Recovery (refresh your mind here, here and here). But as they say all good things must come to an end. Time certainly does go too quickly when you are having fun doing field work at Arid Recovery, especially when you are working with unique animals like the bilby. Two and half years ago I embarked on an amazing adventure that took me all the way from the yellow sands of Bondi Beach, Sydney, to the red desert of Roxby Downs, South Australia. As soon as I heard that there was a PhD project investigating the prey naïveté of Australian native mammals, like the bilby, I knew I had to be a part of it!


Figure 1: The Greater Bilby Photo credit: Lisa Steindler

Prior to European settlement the bilby was found over 70% of Australia. Unfortunately, today they are considered legally extinct in the wild in South Australia, New South Wales and Victoria. The biggest identified threat and cause for this decline has been the introduction of exotic predators, such as the red fox and feral cat.

Thanks to the amazing work by organisations, such as Arid Recovery, feral free reserves have been established. The bilby population at Arid Recovery has boomed within this ‘safe haven’ for reintroduced species. But what happens when you breed animals in an environment where there are no predators? Do they lose all recognition of predators? Can we release them outside the fence where there ARE feral cats, red foxes and dingoes? Like many others we want to see Australian mammals beyond the fence and back in the wild and my PhD research is a step in that direction.

Now onto some basic theory behind that term “prey naïveté”, what exactly does it mean?!  If a prey animal is able to recognise a predator, they may be able to decrease their chances of being eaten. This is often known as an ‘anti-predator’ response. Whether a prey animal is able to recognise a predator may be influenced by their lifetime experiences. Animals may learn through personal experience whether another animal is a friend or an enemy who wants to eat them. Sometimes prey may not be exposed to predators within their lifetime, but they are still able to recognise and respond to them (i.e. in the case of animals living within the Arid Recovery Reserve). Animals that have lived with a particular predator for hundreds and even thousands of years may have “hard wired” responses to this predator. On the other hand, sometimes isolation from all predators over an animal’s lifetime or over hundreds to thousands of years can lead to the loss of all ‘anti-predator’ behaviours – “prey naïveté”.  

Understanding if prey are able to recognise and respond to a predator is important.

Theories on prey predator discrimination and recognition are divided as to whether prey species’ ability to recognise and avoid predators is proportionate to the duration of evolutionary exposure to specific predators or is a result of more generalised discrimination processes. Moreover, the understanding of the timeframes necessary for prey species to maintain or acquire appropriate responses to introduced predators is poorly understood. To be able to answer the question of how we can teach our native animals to be more aware of introduced predators we first need to understand what their current level of understanding is.

I attached radio transmitters to 18 bilbies at Arid Recovery so that each day I could radio-track sleeping bilbies to their burrows. Faecal samples from cats, dogs and rabbits were placed on the outside of bilby burrows to see how they would respond, as bilbies often use their strong sense of smell to recognise predators. Remote cameras were used to film the response of bilbies to the olfactory cue as they emerged from their burrow. The idea was that bilbies had to decide whether it was safe enough to exit the burrows when the faeces were present. If they recognised the faeces as a threat, then they should be more hesitant to leave the burrow compared to when they did not recognise it as a threat.


Figure 2: I radiotracked 18 bilbies for three months with the help of wonderful volunteers.                 Photo credit: Lisa Steindler

Figure 3: Camera traps were used to film bilby emergence behaviour. Photo credit: Lisa Steindler

Video analysis of burrow emergence behaviour determined that bilbies were indeed more hesitant to leave the burrow when certain predator scent was present. Bilbies spent more time only partially emerged (with at most head and shoulders out) as opposed to fully emerged (standing quadrupedally or bi-pedally, fully emerged from burrow) from their burrows when dog faeces were present, in comparison to faeces of cats, rabbits and an unscented control. The Greater Bilby has shared over 3000 years of co-evolutionary history with dogs but less than 200 years with cats. The ability of prey species to respond to the odours of predators relates to their period of coexistence. The longer that you have known your predator over evolutionary time may influence whether you can recognise their odour, even if you aren’t currently living with them.



Figure 4 and 5: What was classified as a partially emerged bilby vs a fully emerged bilby.            Photo credit: Lisa Steindler

This research is only the starting point to seeing a future for bilbies beyond the fence. This research would suggest that despite at least 15 years of isolation from placental predators, bilbies retain some level of “hard wired” recognition of their historical predators (dingoes). The next question will be: Can they survive predation attempts by these predators? Can we teach them to be a bit more aware of introduced predators such as cats and foxes? And can adapt to live in a changing world outside the fence where these predators now exist?

Thanks to all the wonderful support from my supervisors, Arid Recovery staff, and volunteers along the way, I have had an amazing PhD journey that has led to many moments of blood, sweat and tears, a growing family of wonderful friends and precious memories of a unique, charismatic animal ... the bilby!!

Written by Lisa Steindler, PhD candidate with the UNSW. 


Bilby Tails Part II: Trials, Tribulations, Traps and Transmitters

Admin Aridrecovery - Friday, November 20, 2015

If you are a regular visitor of the Arid Recovery blog, you might have read a bit about the ‘bilby business’ that has been happening at the Reserve over the last few months. With the latest experiments on our resident transmitter-equipped bilbies wrapping up at the beginning of November, the final task of retrieving the transmitters has been on the agenda of many of the staff, students and volunteers at Arid Recovery.

For UNSW PhD student Lisa Steindler, removing the remaining tail transmitters from the last 10 of her caught Greater Bilbies (Macrotis lagotis) is just as important as putting them on. Not only are tail transmitters expensive pieces of equipment (retailing at over $200 each), they can be turned off and reused for further research at a later date. Re-catching bilbies can also provide some interesting data on how their weight and body condition has changed over time.

You may be asking “Shouldn’t it be easy to re-catch a bilby, especially if you can track where it is?” Prior to undertaking this task, I would have replied “Sure, we’ll just put a trap in the bilby’s burrow entrance, he’ll waltz on in and gladly hand over his transmitter!” After (finally) retrieving the last transmitter earlier this week, I can safely say that recapturing bilbies is not as easy as one may think. Below I have provided some short explanations of the possible scenarios that I came across during our time recapturing 10 bilbies.


Scenario 1: The tail transmitter falls off.

Transmitters recovered from bilbies: 5 (Romeo, Boomer, Bob, Betsy and Bruno)

Difficulty of retrieval: Varies from pleasantly easy when the bilby conveniently sheds the transmitter above ground on a sand dune (see figure 1), to back-breakingly difficult when it is lost metres down a burrow (see figure 2).


Figure 1: A tail transmitter left on a sand dune by Romeo. The most difficult part of retrieving this transmitter was bending down and picking it up. Credit: Lisa Steindler


Figure 2: Finding a transmitter in a burrow involves 3 steps. 1) Using the radio tracker, find the strongest signal emitting from the ground. 2) Dig, dig and dig some more. 3) Repeat as necessary until the transmitter is found. This process can take as little as 5 minutes or as long as 5 hours. Credit: Lisa Steindler


Scenario 2: The bilby is caught using a trap.

Transmitters recovered from bilbies: 4 (Bellamy, Brian, Bolt, Bullet and Bruce)

Difficulty of retrieval: Depends. The initial set-up of a pen trap can be labour intensive (figure 3), but if a bilby goes into one of the set traps on the first night, all that hard work pays off. On the other hand, trying to catch a bilby hiding in a bettong warren can prove difficult when the only animals you catch for 2 nights are Burrowing Bettongs (Bettongia leuser) and a goanna (Varanus gouldii). Once the bilby’s neighbours have been moved, trapping can be successfully achieved (see figure 4).


Figure 3:  A completed pen trap. Constructing a pen trap involves identifying the number of entrances in the warren, building a fence, complete with footnetting around said warren and wiring traps around and inside the fence. Thankfully, with the help of the Green Army, many hands make light work! Credit: Lisa Steindler


Figure 4: When a pen trap is set up around a warren, it is common to trap a neighbour or two instead of the target bilby. In this case, a Sand Goanna is being coaxed out of a trap by Green Army member Jesse. Credit: Adrian Friedel


Scenario 3: Volunteers are led along a 3-week chase by Bill, a cunning escape artist bilby.

Transmitters recovered from bilbies: 1 (Bill)

Difficulty of retrieval: I wouldn’t recommend this scenario to anyone. After 5 days of pen trapping (figure 5), over a week of rain delays, a further 3 days of failed burrow trapping (figure 6) and 1 mornings worth of digging, Bill was finally re-caught the same way he was caught (figure 7). In a net.


Figure 5: Some may think that 6 traps for one bilby might be too much. In this case, it proved to be not enough, with Bill the bilby escaping under the fence from this pen. Credit: Lisa Steindler


Figure 6: Trying a different tact. After residing in a few single-entrance burrows, we thought Bill might fall for a well-baited trap. As you can see, we were wrong. He burrowed straight under instead. Photo Credit: Sam Fischer


Figure 7: Success! After escaping a pen trap, and burrowing around several burrow traps, Bill was caught by digging behind his burrow, flushing him out and into a net. Credit: Bec West


Now, as the last removed tail transmitter is turned off, I’ve had a moment to reflect on the past few weeks. Having the opportunity to work with (arguably) one of Australia’s most iconic endangered animals has been one of the many highlights during my time volunteering with Arid Recovery. The excitement of seeing those distinctive big ears, and the satisfaction of removing the transmitter after weeks of collecting data far outweighs the many early starts, hours behind the shovel, and patience-testing moments. 


Written by Sam Fischer, Arid Recovery Volunteer and Roxby Downs Green Army Member.

Scaredy-cat

Kimberley Solly - Wednesday, November 04, 2015

Lisa Steindler is not like many other PhD students. Not many PhD students can say that they travel over 1,820 km from Sydney to be up close and personal with the Australian outback, but also a mammal that has faced great challenges. Like so many other Australian mammals, the Greater Bilby (Macrotis lagotis) has faced rapid population decline and severe range contraction associated with predation by cats and foxes. Believe it or not, but the Greater Bilby is actually the lucky one. Lucky in that the other species of bilby, the Lesser Bilby along with 29 other mammal species have gone extinct since European settlement around 250 years ago.


Lisa Steindler and volunteers Liz, Sam, and Sam. Credit: Lisa Steindler

Lisa’s research is part of a much larger project occurring at Arid Recovery, which is the Australian Research Council Linkage project with the University of NSW that we’ve mentioned herehere and here. Titled ‘Tackling prey naïveté’, the research project is investigating the reasons for the extinction of our threatened species and why their re-introductions fail. It is believed that these failures may be because our threatened species might not have the correct anti-predator responses to introduced predators. While fenced reserves are providing much needed reprieve from cats and foxes, this protection may actually be hindering the restoration of threatened species in the long run. Isolation from predators may lead to more naïve populations that are unable to cope with predators (Blumstein 2006).

Beauty and naivety are a dangerous combination. We already know that the bilby is beautiful; Lisa’s task is to determine the degree of naïveté of the Greater Bilby. Lisa is investigating different behavioural characteristics of the bilby such as their vigilance behaviour when foraging (how often they look up to check for danger) and how they respond to the smell and sight of predators.

Thankfully Lisa is well versed in life in the semi-arid and arid zone, with stints as an intern, volunteer, and employee across reserves/sanctuaries such as Scotia Wildlife Sanctuary and Newhaven Sanctuary to name a few. While at Arid Recovery, Lisa has undertaken a number of different experiments, which all require a variety of skills. This year’s research kicked off with catching 30 bilbies across the Main expansion, First expansion and Red Lake expansion and fitting them with radio-transmitters attached to their tails. The ARC project and Arid Recovery intern Ruth Shepherd wrote an excellent summary on how to catch a bilby here.


Volunteers processing a Greater Bilby. Credit: Lisa Steindler

We know that predators deposit urine and faeces throughout their home range, so Lisa is mimicking this to see how bilbies respond. Lisa tracks each bilby to their burrow (using their radiotransmitter) and then places scat from a cat, dog, rabbit or nothing (control) outside their burrow. Lisa has had to ask the Roxby Downs and Port Augusta locals for lots of cat and dog scats and has had help in collecting rabbit scats from outside the dunes by a whole heap of dedicated volunteers! The burrow entrance is then filmed using infrared motion detector cameras to see how the bilby responds when it emerges from its burrow.


Volunteer Rob collecting rabbit scats for experiments. Credit: Lisa Steindler

In a different set of experiments Lisa has also been testing whether bilbies recognise a cat as a predator by placing a taxidermy model of a cat, rabbit or bucket (control) outside their burrows. If the bilbies recognise these odours or models as a predator threat they should show fear which can be measured by how vigilant they are. When Lisa gets back to Sydney she will watch the videos and score how long each bilby spends relaxed or vigilant and compare this to the scat or model that was outside their burrow.



Taxidermy cats and rabbits placed outside burrows were filmed to assess bilby vigilance. Credit: Lisa Steindler  

Lisa has been flat out for three months and is deserving of a big rest, in between her casual role as an Australian fauna keeper at Taronga Zoo. Lisa's final task was to retrieve the radio-transmitters by using burrow and pen traps to re-trap bilbies and she leaves us with some wise words:

“If you want to work with digging animals, you’re going to have to learn to like digging holes”



Retrieving radio-transmitters is no easy feat! Credit: Lisa Steindler


Written by Kimberley Solly, Scientific and Education Officer and Rebecca West, Research Officer ARC Linkage Project

Bilby Tails: how to catch a bilby (Macrotis lagotis)

Admin Aridrecovery - Tuesday, September 15, 2015

The second Sunday in September is dedicated to National Bilby Day, so what better reason to tell you of our work on the Greater Bilby in the Arid Recovery Reserve. And it just so happens that last week was a busy week on the reserve fitting radio transmitters to bilby tails as part of a project looking at predator awareness in the Greater Bilby, which is being carried out by Lisa Steindler (a PhD student from UNSW as part of our ARC Project). By fitting a transmitter the bilby’s location can be found, so long as you are in a kilometre range.  Knowing where the bilbies are, in particular their burrow, is very useful for Lisa when it comes to setting up her experiments outside the bilby’s home.


However, before a bilby can be radio tracked a transmitter needs to be attached, but only once the animal has been caught -some would say this is the fun part! Here’s also where a team of volunteers comes in handy. Catching a bilby in a cage trap is quite unlikely, instead fast pairs of legs are much more effective. But why does this need a team I hear you ask? Well bilbies come out at night, therefore a person with a powerful torch, called the spotlighter, is important. It is also handy to have a driver to allow a larger area to be searched. Also, when the spotlighter sees a bilby, being able to drive alongside the running animal allows some distance to be gained on the bilby, increasing the likelihood of a catch. When the car stops you need a runner (the final member of the team) to jump out of the car and run after the bilby. Here’s where a fast runner is essential! Believe me, bilbies are surprisingly fast. But they also have the ability to rapidly zig zag from side to side, confusing the best of runners. Therefore to keep track of the bilby two good runners are often better than one! After successfully catching the bilby (using a net or by hand) the animal is then placed into a dark, fleecy bag to keep it calm. All be it fun remember we were catching bilbies for an important reason, so please do not attempt to try this at home.


Unlike the other animals on the Reserve that have radio collars, bilbies have transmitters that are fixed to the base of their tail using Elastoplast. Previous studies have found that bilbies can often get their feet stuck in collars, so tail transmitters are much safer. However, attaching the transmitters directly to the tail fur of the bilbies is not effective -sand is more likely to get stuck in the Elastoplast  and cause the transmitter to fall off, so the transmitters must be taped to the skin…This is when hairdresser Lisa comes into action (see the photos below)!


The skilled art of fitting a transmitter to a Greater Bilby's tail! Credit: Ruth Shepherd

After the bilby’s transmitter has been attached other important data such as the animal’s body condition is taken by feeling how much fat the bilby has on the rump area. Some of the fur is also collected to be sent away for analysis for cortisol levels (a measure of stress). This allows Lisa to compare stress levels between bilbies living in the expansion with the cats, and the expansion with no predators.

The final piece of data collected is behavioural data which is done when the animal is released in the place where it was caught. Animals differ in how bold or shy they are, and having one of these qualities may make them better at surviving predation (the ARC project is researching this for bettongs, bilbies and stick-nest rats on the Reserve). Bilby boldness is measured by how long it takes, and how much encouragement it takes (by giving the bilby gentle nudges every 3 seconds), before the bilby leaves the bag.

All of the radio tagged bilbies are monitored by Lisa to see their usual pattern of burrow use and behaviour and then how this changes when the bilbies are presented with a model predator or predator poo outside their burrow. Lisa will compare the responses of bilbies that have been living with cats to those that have not to see if there are any differences. This data will be incredibly useful for Arid Recovery in the long-term to test whether predator awareness of bilbies can be improved if they live with a small number of predators (cats in this case). Lisa will also be able to determine whether there are certain behaviours that we can select for when choosing release animals to make them more likely to survive when faced with real predators in reintroductions outside the reserve.

This article is in honour of the Greater Bilby, once common throughout arid Australia but now only occupies 20% of its former range. We hope through the efforts at Arid Recovery that bilbies will be able to be re-introduced into other areas of arid Australia and their numbers will begin to increase. 


Written by Ruth Shepherd, Arid Recovery and ARC Research intern.

Tracking the tracks in the sand

Developer 2 (MM) - Wednesday, August 13, 2014

The rich red sands of the Roxby Downs area are a photographers dream, providing contrasting with a vivid blue sky or melding into one of those well-known rich outback sunsets.  They are also the perfect tool for monitoring the movements of all who live within the Arid Recovery reserve.

Every three months the staff head out as the sun rises, trekking across kilometres of sand dunes counting the numbers of animal tracks crossing the drag line established the afternoon before.  Not only must the number of tracks crossing the drag be counted but also who made them including bettongs, bilbies, stick- nest rats, western barred bandicoots for our feral free sections and rabbits and cats in our Red Lake Expansion and Dingo Pen. 

The Arid Recovery track transects were established in 1999/2000 after the reintroduction of the Stick-nest Rat, Burrowing Bettong and Bilby. Initially, the species were monitored using radio collars but after 6 months the collars were removed. Initial attempts to monitor all species using cage and large Elliott trapping found that trapping was time consuming and many animals were trap shy.  Trapping also did not sample species consistently with burrowing bettong lining up to get into traps and bilbies avoiding them like the plague. The dunes at Arid Recovery have soft orange dune crests which are perfect for recording track imprints. All reintroduced mammal species at Arid Recovery could be identified by their distinctive tracks making track transects an ideal way of monitoring post release changes in distribution and relative abundance.

Helen Crisp shows Tyson Brown how to measure bibly tracks. Photo by: Kylie Piper

We established 10km of walking track transects in the Main Exclosure which were sampled on the morning after a windy day and calm night. The wind blew away the old tracks so that only fresh tracks were recorded. Later a quad bike was used to drag a bar and chain over the dunes to obliterate old tracks.  This made things easier as it meant we didn’t have to wait for a windy day to do our sampling!  Transects were conducted up to 4 times each year and the number of tracks of each species were recorded per kilometre. Later, we extended the transects to include the first and northern expansion as animals were reintroduced into those areas.  Recently, we have also included measurements of bilby tracks along transects to determine population demographics and breeding events at the time of sampling.

Although track transects do not result in a population estimate they are extremely useful for determining fluctuations in abundance, relative abundance of different species and population spread across the reserve. They can also be calibrated to population estimates derived through capture mark recapture and removal studies.  Transects have the added advantage of also recording any feral animal tracks, allowing for swift removal of any incursions. The transects have now been sampled for over 10 years and I am currently analysing long term trends as part of my PhD. I am comparing distribution and abundance of tracks with post-release factors such as rainfall, time since release and temperature. Results will help determine the most effective reintroduction strategies for each species and increase our understanding of the dynamics of pre-European arid zone mammal fauna.  

Identifying animal tracks isn’t always easy for beginners but here is what we are looking out for:

Burrowing Bettongs have two large hind feet and move in a hopping motion, leaving footprints similar to a kangaroo.  Often you will see the mark of their tail dragging in the sand behind them.

Greater Stick-nest Rats have small footprints similar to those of a cat with a central pad surrounded by four smaller pads for their toes.

Greater Bilbies have large toenails on their hind feet which leave a distinct drag mark in the sand as they hop.

Western- barred Bandicoot hind feet leave an odd sideways V shaped print as they scamper along.

Native Grazers: friend or foe of native plant species?

Developer 2 (MM) - Wednesday, August 13, 2014

Most of us are aware of the impact that grazing and trampling by stock and rabbits can have on plant communities across the arid zone. However, little is known about the effects of native grazing animals, particularly medium sized mammals which are now largely extinct across most of arid Australia.

The Arid Recovery Reserve is home to a number of these mammals, including burrowing bettongs, bilbies, bandicoots and stick-nest rats. While establishing populations of reintroduced species within the Reserve has been very successful, we also need to know what effect these animals are having on our plant species.

Since 1997, a number of monitoring sites have been established by Arid Recovery, in collaboration with DEWNR’s Pastoral Branch. Arid Recovery has been monitoring plant cover, condition, diversity and recruitment to determine the effects of introduced herbivores (i.e. rabbits) and reintroduced herbivores (i.e. our bettongs, bilbies, bandicoots and stick-nest rats) on native vegetation communities within the arid zone, and to determine the strongest indicators of change.

Arid Recovery was recently awarded a grant from the South Australian Native Vegetation Council to analyse the data collected as part of the vegetation monitoring, which provided the opportunity to examine hypotheses based on what sorts of changes we expect to see at a landscape scale. A number of researchers at Arid Recovery have also carried out specific studies to investigate whether native herbivores actually provide a benefit to the arid ecosystem, rather than the devastating impacts of introduced herbivores such as rabbits.

The changes in vegetation that we would expect to see include a reduced impact of native browsers on plant recruitment compared to that of introduced species, with higher survival and growth rates of seedlings in areas where rabbits and livestock are excluded. The level of impact, however, is likely to vary depending on the density of individuals within an area.

One Arid Recovery study showed that low to moderate densities of bilbies, bettongs and stick-nest rats have a significantly lower impact on shrub recruitment than low densities of introduced cattle and rabbits.  Recruitment of common species such as mulga, silver cassia and sandhill wattle was reduced or arrested by even low densities of cattle and/or rabbits.  Evidence from this study suggested that mulga may suffer regional declines if recruitment continues to be suppressed by rabbit and cattle browsing. Another study conducted at Arid Recovery has shown that foraging pits dug by bilbies and bettongs may facilitate seedling recruitment. Bilby digs can trap moisture and minerals, creating nutrient rich soil.

A bilby dig at the AR Reserve, showing how it collects seeds, grasses and plant matter, increasing nutrients in the soil at that point.

Arid Recovery is continuing to monitor vegetation changes in response to the presence of introduced and native herbivores. Continuing analysis of the monitoring data should allow us to determine the most effective indicators of change, not just within Arid Recovery but on a landscape scale. Our research will highlight the importance of establishing indicators of overstocking of native species in fenced areas like Arid Recovery, may also assist with developing novel revegetation strategies such as changing the habitat for direct seeding by mimicking animal digs.

Termites and toilet rolls

Developer 2 (MM) - Wednesday, August 13, 2014

Termites play an important role in the environment. They are important providers of ecosystem processes such as nutrient recycling, decomposition and as a by-product create homes for lizards, birds, ants and mammals. Incorrectly called ‘white ants,’ not all termites eat wood and damage your house. Out of the 350 species that occur in Australia, only 12 damage timber. Latrobe PhD student Nicole Coggan first visited Arid Recovery in 2011 to study the effect digging marsupials (bettongs and bilbies) have on termites. She is now in the process of analysing her data.

Bilbies and bettongs are regionally extinct throughout Australia. Nicole wanted to investigate if their reintroductions and incessant digging influenced termite and ant assemblages across a series of habitats. Nicole’s study involved the mammoth task of digging a trench in four different habitats inside and outside the Reserve and counting and identifying every single termite she found, weighing them and calculating their biomass. If termites had the chance they would live everywhere, unfortunately for those at Arid Recovery they share their environment with those pesky digging marsupials. The presence of reintroduced bilbies and bettongs reduces termite abundance by 50% and a decline in termite genera present.

Collecting termites for weighing and analysis- those with poor eyesight need not apply to volunteer! Photo by: Nicole Coggan

The second part of Nicole’s study looked at the consequences of marsupial disturbances for termites, or also known as the toilet roll experiment. Using over a thousand toilet rolls to attract termites, Nicole and her swagger of volunteers buried them in the soil inside and outside the Reserve. Six months later Nicole returned and pretended to be a bilby digging in the soil. Nicole was able to compare how quickly the termites fled when they were disturbed by the faux bilbies inside versus outside the Reserve. After 24 hours almost 75% of termites were lost from the disturbed rolls inside the Reserve compared to 50% from outside the Reserve. More bad news for the termites, opportunistic ants are attracted to the disturbed toilet rolls, who will eat termites. Death generally awaits termites insides the Reserve.

 

One of the toilet roll study sites. The sticks helped Nicole to find the individual toilet rolls upon her return 6 months later. Photo by: Nicole Coggan

It’s not all bad for termites. Unlike our reintroduced marsupials there is no danger of them becoming extinct. Although termites are affected by soil disturbance made by digging marsupials, they are able to change the way in which they use their habitat. They avoid resources and habitats frequented by bilbies and bettongs.

Nicole's study would not have been able without assistance from LaTrobe University, the Australian Wildlife Conservancy, Holsworth Wildlife Research Endowment and Arid Recovery.

Roxby Christmas Pageant Rocks

Developer 2 (MM) - Wednesday, August 13, 2014

This crazy time of year that we call the festive season has rolled around again and everyone in Roxby Downs is embracing the Christmas cheer. The first of December is traditionally when many families decorate their Christmas trees and switch on their festive lights, this year it was also the evening on the Roxby Downs Community Christmas Pageant.

After such success last year, Arid Recovery decided to team up with their friends at St. Barbara’s Primary School again. The theme this year was St. Barb’s Arid Ark, with students turning the float into a giant ark, with a range of animals.

With the heat of summer coming early this year, staff and students were prepared for a hot one, but half an hour before the pageant was due to start the skies had darkened and lightening was flashing across the sky of Roxby Downs. The AR staff raced off to collect Macca the giant bilby from the Reserve, ready in time for the pageant start. With all floats lined up and students ready to take their place the heavens opened and the Roxby pageant became a very soggy event.

Luckily the clouds cleared eventually and we were able to finish the pageant with some sunshine. Macca thoroughly enjoyed the pageant, blowing kisses and dancing for the crowd. A big thanks goes to the staff and students of St. Barbara’s Primary School, for helping to decorate the float and taking part in the pageant on the evening.

For more photos from the pageant check out our Facebook page.

Keeping cool in the desert

Developer 2 (MM) - Wednesday, August 13, 2014

Summer has announced its arrival in Roxby Downs with week of hot dry days, averaging about 38 degrees and frequently jumping over 40 degrees. So while many were lounging around under the air conditioner with the cricket on the telly, or heading to a mates house to jump in the pool, we were wondering just how our Aussie critters cope with this heat. Below are just a couple of ways native animals have learnt to survive summers in the harsh Australian outback.

Evaporative cooling: Just like humans, some animals sweat to help cool themselves down, with the breeze blowing on the surface of their wet skin helping to cool them down. Some animals are not adapted to sweat though, rather they pant which helps them to release some heat, kind of like your pet dog does. Some animals may lick themselves too, spreading their saliva across their body to create damp surfaces for evaporative cooling to occur.

Faeces: Water is hard to come by, so the systems within an animal’s body will try to retain as much water as possible. Animals adapted to live in arid zones will produce very dry faeces, trying to retain water. Their bodies are also able to produce antidiuretic hormone, which helps to concentrate the urine, ensuring as much water as possible stays in the body.

Water sources: As you would most likely know, there are many animals that do not need water to survive (unfortunately our feral cats have adapted to this too!). Many of our animals at the Arid Recovery Reserve such as bilbies and bettongs, obtain their water throughout the process of breaking down the foods they eat.

Body features: Some animals have rather long legs, possibly to keep their bodies away from the ground and the heat that radiates up from it. Others, such as our bilbies, have large thin ears, with many blood vessels flowing through them. Due to their large surface area, heat from the blood passing through their ears is allowed to escape.

A photo with a torch shone through a bilby ear, depicting the large pores and the veins that run through their ear to help release heat and cool them down. 

Burrows: We took a couple hints from the bilbies and the bettongs when houses were first built in Coober Pedy, with many people choosing to dig them under the ground. Studies have shown the temperature variation between burrows and the surface to be quite significant, in some areas it is up to 20 degrees cooler inside the burrow compared to the outside temperature.

There are many more adaptations our Aussie animals have developed to keep themselves cool over the summer, these are just a few. We might revert to our previous comments though and head to the pool!

Bilbies in the fight against global warming!

Developer 2 (MM) - Wednesday, August 13, 2014

We already know well that rabbits have wreaked havoc on the Australian landscape, eating up our native plants and kicking some of our native mammals out of their homes. And those little holes that they dig all over the place that you might be unlucky enough to roll your ankle in aren’t too good for our environment either! Whilst our bilbies and bettongs dig similar holes, it has been shown they are much more beneficial for the environment.

A study completed at Lorna Glen in central Western Australia used data loggers to record temperature and humidity, amongst other things, in bilby diggings, and in areas that had not been disturbed. The results showed that the microclimate (the climate inside the bilby digging) compared to that in areas of soil that were not disturbed, was not as variable. The difference in humidity levels and temperature during the night and day, was not as great as that in other areas. For a quick over view of the findings, click here.

Arid Recovery has also completed research on the role that bilby digs play in ecosystems, and has some interesting results. The data showed there were higher levels of carbon in bilby digs, compared to those of rabbits. Our native species are helping us try combat global warming! Data about the rate of mulga germination also shows that our native fauna helps out our native flora. Rates of mulga germination are higher inside bilby digs when compared to rabbit digs or undisturbed soil. This could be due to a number of factors, possibly higher levels of nutrients in bilby digs due to exposing the deeper soil which is more fertile than the top soil, or the small hole collecting leaf litter and water, which breaks down to increase soil fertility.  

 

A graph depicting the average percentage of carbon in a bilby dig compared to the soil surface. Graph by Alex James

A graph depicting the average number of mulga seedlings in bilby digs compared to rabbit digs and the surface. Bilby digs have nearly 3 times more seedlings than rabbit digs or on the surface! Graph by Shannon Sparkes

Thanks for some of the research and findings about bilby digs and their roles as environmental engineers must go to a number of students we have hosted over the years.

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Arid recovery is a conservation initiative supported by:
bhp
adelaide university