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.

Green Army ‘fights’ for Arid Recovery values

Kimberley Solly - Friday, November 13, 2015

“It’s going to be a hotter-than-average summer”. I don’t know how many times I’ve heard that sentiment over the last few months, and judging by the conditions of last few weeks (and the swathes of meteorological and oceanographic data relating to El Nino) it’s a fact that’s hard to dispute.  For a Project like the Arid Recovery Reserve, this means the heat reflecting off those polished red rocks, and the hot sand that pours into your boots on the ascent of every dune, will be harder to bear than ever.  But I’m not deterred.  The necessity for vigilance regarding the maintenance and welfare of the Reserve’s infrastructure, and its many furry inhabitants is something that doesn’t go away just because it’s hotter than usual.  A team of motivated and dedicated ‘warriors’ is required, and that is something I will be proud to contribute this summer in my role as Supervisor for the Roxby Downs Green Army Project.


Working hard to maintain the integrity of our fence. Photo credit: Adrian Friedel

The Green Army is an Australian Government initiative open to young people aged 17-24, who are looking to develop skills, undertake training and gain experience in the delivery of conservation projects.  Through the Green Army programme, participants enhance their opportunities for careers and further training in conservation. The Roxby Downs Green Army Project works in partnership with the Arid Recovery Reserve to achieve goals relating to species conservation in the arid zone. My team is only small (three people) but we work diligently to complete a range of objectives including fence maintenance, pest and weed surveys and vegetation monitoring.

The values of the Arid Recovery Reserve stand for a lot of things. Among them is the demonstration that a lot of hard-work and dedication towards a particular cause can eventually pay off.  I like to think that my team is following in the footsteps of Reserve ‘pioneers’, who have dedicated much time and energy in building and maintaining this unique facility. One of the major drivers in achieving this is ‘passion’, and ‘passion’ is something I find reflected in all of my team members, whether it be a desire to learn more about local flora and fauna or just the willingness to work hard on a task for the satisfaction of seeing a result take effect.  Each set of eyes on the Reserve improves the ability to detect unusual diggings or evidence of species that may (or may not) supposed to be there, and contributes towards the ever-expanding record of opportunistic sightings and phenomena.

The opportunity to get up close and personal with some of the Reserve’s furry (and sometimes scaly) critters is a fantastic reward and definitely something my team looks forward to. When a visiting researcher sticks their hand up looking for assistance, we are quick to jump at the opportunity.  Constructing little pens to trap burrowing animals is a job that requires multiple sets of eventually blistered and calloused hands, but the 5am starts and the hordes of flies are soon forgotten when given the opportunity to handle and process a captured bettong or a bilby. We are very lucky.



Green Army participants setting up a pen trap to catch a Bilby and then processing their Bilby bounty! Photo credit: Adrian Friedel

I want my team members to come away from this Project, at the end of February, seeing this unique environment through different eyes, and knowing that they have contributed towards important conservation goals.  We are currently looking for an additional team member for the summer and the next Green Army Project begins in February (and will run for around 22 weeks). Anyone who is interested or has any questions is invited to contact me by emailing me at greenarmy@aridrecovery.org.au.


Written by Adrian Friedel, Supervisor for the Roxby Downs Green Army Project.

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

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