Education Centre opens

Admin Aridrecovery - Tuesday, April 24, 2018

Education Centre Opens

Over two years in the making, a new Education Centre is at last open on the Arid Recovery Reserve.

The Centre contains a large classroom space, two bunkrooms and a bathroom. Visiting school children, university students, professional groups, friends and families can now get out of the heat, the wind and the flies to listen to presentations, get into crafts, work through exercises, or even watch a movie. We can now sleep up to 18 people on the reserve. Maybe most notable of all: the reserve now has a flushing toilet – how about that for creature comforts!



Andrew Harris (BHP) and Eddie Hughes MP officially open the Education Centre. Photo: Kathryn Hollingworth

This is possibly the cheapest Education Centre ever built in South Australia, and we’re proud of that. It has truly been a community effort. The buildings were donated by the Roxby Downs Caravan Park in 2015 and moved into place by Toll, where they sat idle for a time until we raised the funds to do them up.


Old portable buildings were donated by the Roxby Downs Caravan Park in 2015 and sat idle on the reserve before we could raise the funds to do them up.

 

Thanks to the support of our community and friends in the Far North, we received state government funding through Fund My Idea to turn the Education Centre into a reality. With some extra funding provided by BHP, we were able to engage builder Ashley Stevens to join the long skinny buildings together to make a larger classroom. It wasn’t a particularly nice job working with these old portable buildings, but he did stellar work making them into a solid new structure.


You have to break eggs to make an omelette. Here our builder has joined two buildings together and begins the task of gutting them to make the classroom.


Several local businesses contributed their time and services to the renovations, including Mossy Electrical, Balaklava Stitch Joint, Minetech and Spotless. Roxby Downs District Rotary Club members came out on working bees, along with other volunteers from the community and further afield. We were very fortunate to meet Lionel and Sylvia, a volunteer couple who stopped in with us for three weeks to paint the centre and add all the little trimmings.



Hard working volunteers put their backs into digging a trench to connect the new centre to the solar power system.




Volunteers Lionel and Sylvia did an amazing job painting the inside walls and adding all the trimmings.



Spotless donated their time to paint the outside.

 

Thanks to all our friends and supporters in the Roxby community and beyond. We look forward to hosting you at the new Education Centre sometime soon.

 


The finished classroom. Artworks are displayed from science-arts workshops held throughout the year with the support of Inspiring South Australia.

Annual Trapping 2018

Nathan Beerkens - Tuesday, April 17, 2018

Annual Trapping 2018

By Kirra Bailey & Ben Stepkovitch

Annual trapping occurs in the start of March each year, with the session occurring for 5 consecutive days. 2018 marked the 20th year that Arid Recovery has conducted annual pitfall trapping, alternating each year between dune and swale sites, both inside and outside the reserve.

It cannot be done without a small army of staff, interns and volunteers. This year we had 19 people, split across 4 teams, including staff from Arid Recovery, Bush Heritage Australia, the SA Department for Environment and Water (DEW), Mulligan’s Flat Woodland Sanctuary and BHP Olympic Dam and volunteers.

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Our staff and volunteers hard at work. Photos: Nathan Beerkens

This year, we were trapping on the dunes. Our first day started with setting up a low fence-line running through the middle of our pitfall traps, which thankfully have already been dug in for us. Each site consisted of two lines of pitfalls with six pitfall holes on each line. This year, for the first time, we also trialed putting false floors in the bottom of pits - to provide reptiles a place to hide from any mammals that were also caught.


A false floor ready to be placed in a pitfall trap. Photo: Nathan Beerkens.

After each site was set up, the lids of each pit were removed, ready for critters to fall on in. Each site was checked for all animals and invertebrates in the early mornings at sunrise and in the late afternoon as the sun was setting. All vertebrates caught in the traps were placed in individual catch bags and then taken back to the lab for processing. Processing of the animals involved determining sex, measuring their body parts and weighing each individual animal. After being processed, the animals were kept safe in the lab until evening and were released at the same site they were captured.

Left to right: Plains mouse (Pseudomys australis); volunteer Kristi Lee with a juvenile sand monitor (Varanus gouldii). Photos: Ben Stepkovitch.

Every annual trapping session that we conduct each year is just as important as the next as it provides Arid Recovery with accurate long-term data. This allows comparisons between the abundance and diversity of the small mammals and reptiles found inside and outside the reserve to be made over time. This in turn can help determine whether specific animals are doing better in specific places.


Left to right:  Central Knob-tailed gecko (Nephrurus levis); Burton’s legless lizard (Lialis burtonis). Photos: Nathan Beerkens.

This year we caught and released a whopping total of 719 animals (including 563 individual animals, as some were recaptured during the session). There were 420 reptiles and 299 mammals, consistent with previous years trends of capturing more reptiles than mammals. We also caught 462 invertebrates.

Three species of very similar-looking geckos in the lab for processing. Left to right: Beaked gecko (Rhynchoedura eyrensis), beaded gecko (Lucasium damaeum) and crowned gecko (Lucasium stenodactylum). Photo: Sophie Wilkins.

The two main species of mammals caught were spinifex hopping mice (246) and plains mice (49). We caught more hopping mice and less plains mice this year compared to last year as hopping mice prefer to inhabit dune systems and plains mice prefer swales. The most common reptile, with 185 captures, was also a dune-specialist – the southern sandslider (Lerista labialis)

More friendly faces enjoying their annual trapping experience: Jonathan Vosser and intern Kirra Bailey. Photos: Ben Stepkovitch & Sophie Wilkins.

Arid Recovery would like to express gratitude towards all the volunteers who came to help out. Without them, it wouldn’t have been possible. Also, a special shout-out to the Roxby Downs children who gave up their weekend to join us...we see some great budding ecologists there!

Conservation for Kids - Bilby Burrow 2018

Nathan Beerkens - Friday, April 13, 2018

Conservation for Kids – Bilby Burrow 2018

By Nathan Beerkens

How do you get little kids interested in conservation? Or anything?

Make it fun!

Singing songs with 'Toddler Story Time'.

In the build-up to Easter, Arid Recovery and Roxby Traders hosted a week-long series of children’s activities in the heart of Roxby Downs. Around 250 children joined us to learn about the Easter Bilby through arts, crafts, stories and play.

Reading stories about how good bilbies are for Australia.

The arts and crafts activities were bilby-based and included colouring-ins, making bilby homes, making bilby hats and playing with bilby poo (not real).

The ‘poo’ was a hit, and was actually play-dough and glitter. Bilbies eat a lot of bugs and you can see shiny bug pieces in their poo. So, glittery play-dough was a good substitute. On one hand, we’re sorry to all of the parents whose youngsters talked about poo for the rest of the day. On the other hand, we don’t regret it!

A glittery bilby emerging from its play-dough burrow.

Other highlights included a scavenger hunt at the Roxby Downs Nippy Gym, where toddlers searched for hidden plush bilbies, an Easter raffle for people who shopped locally, visits from the Easter Bilby and ‘The Bilby Burrow’ – a sprawling network of cardboard box tunnels which the kids could not stop exploring.

The week was a great success and we’d like to thank all of the organisations and businesses which took part, including Roxby Traders, Nippy Gym, Roxby Downs Community Hub, the Community Library and all of the children’s groups and parents.

Some kids told us that bilbies were their new favourite animals, which we couldn’t be happier about.

As they say: you have to be aware before you can care.

It was great seeing bilbies lining the busiest part of town.

The end of the Western Barred Bandicoot?

Nathan Beerkens - Thursday, March 08, 2018

The end of the Western Barred Bandicoot?

By Katherine Tuft

Don’t worry, it’s not extinct, but a new study by the WA Museum says that the Western Barred Bandicoot isn’t who we thought it was.

Western Barred Bandicoots (Perameles bougainville) once lived over much of southern arid Australia, from Western Australia to New South Wales and Victoria. By the 1930’s, they were extinct on the mainland, largely due to predation by feral cats and foxes. They only survived on two islands (Bernier and Dorre), off the Western Australian coast and are currently listed as Vulnerable to extinction. They have been reintroduced to three predator-free sites: here at Arid Recovery, and Faure Island and Mt Gibson Wildlife Sanctuaries in Western Australia, and there are plans for reintroduction of Western Barred Bandicoots to sites in NSW in the near future.

The Western Barred Bandicoot's former range. Source: Western Barred Bandicoot Perameles bougainville, Burrowing Bettong Bettongia lesueur and Banded Hare-Wallaby Lagostrophus fasciatus National Recovery Plan (2012).

This new study looked at the morphometrics and genetics of museum specimens and concluded that what has been known as the “Western Barred Bandicoot” is in fact five different species. All five were very closely related, and four are now extinct. One of these recently extinct species is the delightfully named Perameles papillon or Butterfly Bandicoot. The only surviving species occurred in the far north-west of the country and is the species which has been used for reintroductions back onto the mainland.

The only surviving species of Western Barred Bandicoot. Photo: Nathan Beerkens

This means that their translocation to Arid Recovery was technically an ‘introduction’ rather than a ‘reintroduction’. Skulls of the now extinct bandicoot species from the region had larger auditory bullae than the other bandicoots. Auditory bullae are bulbous bony structures towards the back of the skull and are thought to amplify sounds. The extinct bandicoot might have had exceptional hearing, honed to detecting predators and prey in its arid environment, but we’ll probably never know.

Nonetheless, the bandicoots reintroduced into the Arid Recovery Reserve are thriving 17 years after their release. From 16 founders, we have a strong population of over 500 and are the only site with mixed genetics from both Bernier and Dorre islands. A recent study shows that not only have the genetics from both islands survived in our reserve, but the genetic diversity has actually increased.

The authors of this new bandicoot study question whether it is right to translocate the only remaining species of western barred bandicoot into areas formerly inhabited by extinct sister-species. In a perfect world, we would have the right bandicoot in the right place, but the Australian landscape has changed dramatically since the original five species of western barred bandicoot skipped and dug their way around the vast outback. Four of those species are completely gone, never to return. Many of their sympatric species of medium sized mammals have disappeared as well, some to last refuges on islands and others lost to history. In their places are hordes of rabbits, and with them feral cats and foxes.

Feral cat. Photo: Hugh McGregor

Busy digging bandicoots perform important functions in the ecosystem, turning over the soil, sequestering carbon and nitrogen, and creating constellations of little compost pits across the desert that facilitate the germination of native plants. This is exactly what bandicoots are busy doing at Arid Recovery. Whatever adaptations this West Australian bandicoot might be lacking for desert life does not appear to affect their long-term survival here. Surely it is better to have the ‘wrong’ bandicoot than no bandicoot at all.

Western Barred Bandicoot being released.

There are cases where moving and mixing groups of animals has been critical for saving species. Mountain pygmy possums foundered for years in remnant populations separated by miles and miles of country. In earlier years, managers took care to retain the unique genetic make-up of each population, on the assumption that animals in each population were especially adapted to the particular conditions at each site. Enormous efforts went into captive breeding, but still the possums failed to thrive. It was later identified that the main failure of the population to increase was due to inbreeding. In a short space of time, with some swapping of animals between populations, the possums are finally breeding well and their future is looking less bleak. You can learn more about this genetic rescue effort in this Conservation article, or watch the Catalyst episode.

I spent my earlier career working with brush-tailed rock-wallabies and continue to pay attention to the efforts to improve the outlook for these fantastically nimble animals. Genetic comparisons of brush-tailed rock-wallaby populations identified three distinct groups (called Evolutionarily Significant Units). Defining a subspecies as distinct from a species or some developing latent subspecies is somewhat subjective and rather fraught. These three groups are considered somewhere below the level of subspecies. And here’s where politics came in. One of the ESUs occurrs solely in Victoria. It did not cross the border into NSW. State legislation, armed as it should be to identify and protect endangered species, classified the Victorian rock-wallabies as Critically Endangered. Large sums of money and years of effort by many talented people were invested in saving the Victorian brush-tailed rock-wallaby. Some of the last remaining individuals were taken from the wild and brought into a captive breeding program. Pouch young were cross fostered onto mother wallabies from other genera (Tammar wallabies; read here) to fast-track the breeding program. And precious new animals were returned to the wild. Despite these herculean efforts, the rock-wallabies failed to do well, there was little successful wild breeding, and various unfortunate misadventures took a toll. In desperation, the Victorian rock-wallabies are now being mixed with rock-wallabies from NSW and the outlook for the species in Victoria is improving.

Brush-tailed Rock Wallaby. Photo: Katherine Tuft

Australian ecosystems are dramatically different now compared to 200 years ago, and will stay that way until feral animals can be fully eradicated. In this much altered landscape, I think it is counterproductive to be too precious about retaining the nuances of genetic variation or restoring landscapes to exactly how they were (or how we think they might have been). I believe we need to accept the state of things for now, and work with what we have. If an equivalent species can perform a similar function in the landscape, it’s better than leaving that role vacant. A slightly different little bandicoot digging around in the red sand is surely better than the gaping absence left by the original bandicoot’s extinction.

Click here to adopt a Western Barred Bandicoot.

In the Spotlight

Nathan Beerkens - Wednesday, January 24, 2018

- In the Spotlight -

Finding animals after dark

Written by Nathan Beerkens

This blog is a tribute to an unsung hero of conservation. A stalwart of science. The spotlight.

Lighting up the night is nothing new for people (who are notoriously bad at seeing in the dark!). Thousands of years ago we had candles, then oil lamps, then light bulbs and finally, in 1899, we invented the handheld flashlight.

By the 1950’s, spotlights were taking a hold in wildlife science and researchers could unlock more of the nocturnal world than ever before. You could look farther across plains, higher up trees and deeper into caves than ever thought possible.

Two spotlights used at Arid Recovery. The red filter lets us watch animals without affecting their night vision.

The spotlight revolutionised wildlife monitoring. Scientists set up regular spotlighting routes to track changes in animal abundances. We use this same tactic today, alongside BHP Olympic Dam. By spotlighting the same routes every three months for years, we can show how wild animal numbers (native and feral) have changed over time in Roxby Downs, Andamooka and our reserve. The data collected over the years has been useful in clearly showing the benefits of calicivirus in not only drastically dropping rabbit numbers but also in reducing the numbers of feral cats and foxes. Read more.

And the beauty of it? It’s simple. Cheap and simple. In saying that though, there’s a few tricks that could mean the difference between seeing heaps of animals, or none at all. Here’s a spotlighting 101:

  1. Hold the torch at eye level. And be prepared to see many eyes staring back at you. Cats, rabbits, foxes, kangaroos, sheep, nightjars, geckos and more. Also, spiders. Many spiders. If you’re brave enough, follow a ground spider’s eyeshine and you will find it. The bright shine will suddenly transform into a living eight-legged creature in front your eyes - maybe tiny, maybe huge. It’s truly a wonder.
  2. Shine at the horizon. If you’re in a car (or even walking), you’ll see more if the top of your light beam is touching the horizon. It can be tempting to shine exactly where you want to look, but shining at the horizon will open up a bigger field of view to see.
  3. Sweep forwards and back. Shine your light forwards, then back in line with yourself and then forwards again. This back and forth sweeping will help you find animals that don’t have much eyeshine, or try to scurry and hide.

Barking Gecko (Underwoodisaurus milii) found at Arid Recovery whilst spotlighting. Photo: Nathan Beerkens

Nowadays, there’s a new revolution in thermal cameras. And they have merit. These cameras, used like an old-school video camera, give warm-blooded animals nowhere to hide against a cold background.

But they have their problems. Firstly, they’re expensive. Secondly, you might need to use them AND a spotlight at the same time (thermal camera to find the animal and spotlight to ID it). And finally, in hot places like Arid Recovery, the background can easily be as hot as the animals we are trying to find! So all the thermal camera sees is a flat wall of heat.

Technology will continue to improve, and no doubt the thermal camera will one day become a key part of the wildlife scientist’s toolbox. But until then, and probably far into the future, the humble spotlight will continue to shine bright, giving us remarkable access to the nocturnal world.

Stickie Haven to go ahead

Nathan Beerkens - Thursday, November 30, 2017

Stickie Haven to go ahead


We put the Greater Stick-nest Rat in the spotlight in “Stickie September” and asked for your help to build a haven for these animals around the new Education Centre at Arid Recovery.

Thanks to our family of supporters and quite a number of new friends, we were able to raise over $5,000. The project can now go ahead.

Critical to our success was this article that appeared in the Age and the Sydney Morning Herald. We were flooded with adoptions for Stick-nest Rats, which until then had been our least popular threatened species for adopting.

The haven project can now proceed. We will fence off several hectares around the Research Station and new Education Centre using 50mm netting. Stick-nest rats can easily move in and out of that size netting, but bettongs that compete for the same food resources will be excluded. With a little bit of planting, we’ll encourage a garden to grow Stickies’ favourite food plants like quandongs and succulent saltbushes.

As well as being a wonderful place for Stickies, the Haven should also mean that visitors have a better chance of seeing and appreciating Stick-nest Rats as they stroll around at night. Encountering these animals is truly delightful, as these gorgeous dumpy rats often get about in pairs and run about playfully circling each other.

A Stickie peers through a roll of wire we’ll use to construct the Haven


Just… a bit… higher… Donated telemetry towers give us the tracking edge

Nathan Beerkens - Wednesday, November 29, 2017

Just… a bit… higher…
Donated telemetry towers give us the tracking edge


Radio telemetry for following wild animals is not a new science. The basics of VHF (Very High Frequency) radio transmitters haven’t changed since the 1980s (read this article from the archives). Batteries power the transmitter to bleep out at regular intervals, essentially just a very boring radio-program you detect with an antenna. The larger the battery, and therefore the larger the transmitter unit, the further the signal can go.

Radio transmitter technology has come a long way in miniaturisation. There are now transmitters small enough to attach to microbats and even butterflies – which are unthinkably tiny at 0.2 grams. Check out this clever lab group sciencing up the art of butterfly tracking.

As wonderful as this miniaturisation is, the fundamental principles of tracking are unchanged. Little transmitters with little batteries can’t transmit their signals very far. Even when units can transmit across a kilometre or so, the signal is often blocked by topography and vegetation. This is particularly problematic for burrowing animals like our burrowing bettongs where the signal transmission is even more limited.

The tried and true method in every field researcher’s book to deal with this challenge is to get a bit of height.

Hugh McGregor trying to pick up a signal with the ‘edge’ given him by a metre’s worth of pallets.

Getting height in the flat desert landscape at Arid Recovery isn’t easy. We’ll use anything we can to get just that little bit higher: the top of the vehicle cab, a pile of pallets and even a broom handle on the end of the receiving antenna.

Researchers in the 1980s were facing this same challenge to track feral goats in the Barossa Valley. They used 12 m tall towers with Yagi antennas mounted at the top to get some much needed height. Thanksfully, the Department of Primary Industries have donated these to us. There are two poles nested together, allowing the antennas at the top to be rotated from the ground to hone in on the direction a signal is coming from.

John Crompton steadies a tower as it is strained down. Photo: Nathan Beerkens

The University of New South Wales team is making use of the towers in the Dingo Pen at Arid Recovery right now, where bettongs have been translocated as part of the prey naivety project.

Next year we hope the towers will be helpful in following Western Quolls as we monitor a reintroduction to the Reserve. Thanks to the Department’s donation, this handy equipment is still useful and very much appreciated 30 years on.


By Katherine Tuft 

On air with the Conservation Conversation

Nathan Beerkens - Tuesday, November 28, 2017

On Air with the Conservation Conversation

By Maddy Wilcox-Kerr, Arid Recovery Intern

In September Arid Recovery hit the airwaves with ‘the Conservation Conversation and if you haven’t tuned in, then you’ve been missing out!

Exploring all things animals, the show focuses on questions that kids from the area have asked each month at market day. We hope to get the kids thinking about wildlife, biology and conservation.

As expected, the kids are most interested in animals of the Aussie outback and we leave no stone unturned in our quest to provide them with fun facts. We’ve covered everything from roos, emus, pythons and even had interest in the burrowing bettong (oh, boy that got us talking!).  But every now and then we get a question that will leave even us biology nerds a little perplexed.  Last week we had a young boy enquire about the number of owls left in the wild. Although I could tell you that there are 11 species of owls living in Australia at the moment, answering how many there are was another matter. Nonetheless, after a quick consultation with our good ‘ol friend Google we were able to provide a somewhat more detailed answer.

On the other hand, some of the less difficult “questions” give us a chuckle. My personal favourites include “Sheep have baby lambs” and “snakes are poison”. I find it hard not to laugh at these comments, but here at Arid Recovery we can turn any small anecdote into an in-depth discussion about wildlife and the natural world.

Without a doubt, there has been a certain re-occurring theme over the course of the show. Kids just love to talk about snakes. Averaging 6 snake questions a show, the kids from Roxby Downs are going to be herpetologists before we know it. If there isn’t at least one child in every family in Roxby that can tell us why snakes are venomous then we have not been doing our jobs properly. 

Finally, one thing that does set us apart from other radio shows in the region is our good taste in music. True to our form our playlists incorporate an eclectic mix of old and new tunes inspired by the animal kingdom. In fact, my favourite part of the show is the preparation of songs for our playlists. From Karma chameleon by Boy George to Cats in the cradle by Harry Chapin, no song is too daggy for the Conservation Conversation.

Our final show for the year is scheduled for the 12th of December at 3pm. So, if you’re interested in animals, want to bop along to some classics or get involved in the general shenanigans that is the Conservation Conversation then don’t forget to tune in to RoxFM 105.5 or stream online


Roxby Downs: A Gateway to the Outback

Nathan Beerkens - Tuesday, October 10, 2017

Roxby Downs: A Gateway to the Outback


Roxby Downs is surrounded by outback wonders that are waiting to be explored. Arid Recovery intern Peta Zivec takes you on a virtual tour.


1. Andamooka

Andamooka is an opal mining town 30km east of Roxby Downs. Let’s put it this way, it’s a very different type of mining than what goes down in Roxby. The town developed from scattered miners’ camps in the 1930’s and certainly has a “Wild West” appeal. Nowadays it’s a sea of mullock heaps with dirt tracks to find your way around town, with scattered homes nestled into the hillsides. Highlights include the Andamooka Yacht Club, which is a trendy Melbourne-style café blonked into the middle of the desert, the public noodling area (aka opal fossicking) and the cemetery on top of the hill which features quirky grave stones of the forefathers of Andamooka.


2. Desert mound springs

Amongst the desolate desert in what appears to be a very hostile arid landscape, up pops a mound spring which is full of life, water and aquatic plants. Mound springs are created by the pressure from the Great Artisan Basin pushing water to the surface. Two mound springs (The Bubbler and the Blanche Cup) are located 190km North of Roxby Downs in the Wabma Kararbu Mound Spring national park. These arid wetlands are an astonishing feat of nature and worth a visit.


3. Lake Eyre

Words to describe Lake Eyre are; breathe taking, mind blowing and remarkable. Lake Eyre has always been very high on my bucket list and this giant expanse of shimmering salt did not disappoint. A chance to experience Australia’s lowest point and largest lake is something unforgettable. With or without water, the immense expanse of space and beauty is incredible. The different landscape types on the Oodnadatta track on the way to Lake Eyre are half the fun and in parts I was convinced we could have been on the moon.


4. William Creek

William Creek is surrounded by the world’s largest cattle station (6 million hectares and the size of Israel), has the world’s most remote pub and is South Australia’s smallest town. Isn’t that enough reason to want to go!? William Creek pub makes a mean beef burger, which is worth the drive alone, and you can also get scenic flights over Lake Eyre. The drive to William Creek along the Oodnadatta track is littered with relics of the Old Ghan railway line. Ruins of rail stations, the water filling tanks for the steam trains and bridges across creek crossing adds to the aesthetic of the outback experience.


5. Gammon Ranges and Arkaroola

The Vulkathunha-Gammon Ranges are a bit more of a substantial drive from Roxby (approx. 400km), but the drive is well worth it. Head North from Roxby along the Borefield Rd and be sure to stop at the Lake Eyre Yacht club in Maree, check out the Farina Ruins and you MUST get a Quondong pie at the Coply Bakery. The Vulkathunha-Gammon Ranges are the Northern Part of the Flinders Ranges and are a geological haven. Pushing of tectonic plates, erosion and a lot of time has created a spectacular landscape. There are fantastic hiking tracks at Arkaroola, plenty of yellow-footed rock wallabies to spot and beautiful vistas of arid mountain ranges.


6. Arid Recovery

Lastly, Arid Recovery is one hell of a place to check out. I invite you to come and join us for a sunset tour, listen and learn what we are all about and soak in the beautiful desert. The red sand dunes, the gibber plains and the fascinating mammals that emerge when the sun goes down are truly unique experiences. A glimpse of what Australia might have looked and felt like before feral foxes and cats roamed freely. To spot a Bettong hopping by or see a Bilby trotting in the distance, is a special thing, and it is a shame not many Australian have had the chance.

I encourage all of Arid Recovery’s followers to put Roxby Downs on top of their travel list and come play with some Bettongs!

By Peta Zivec

Arid Recovery intern

Contraception

Nathan Beerkens - Wednesday, September 27, 2017

Burrowing bettong contraception trial off to a great start

By Holly Cope, PhD candidate from the University of Sydney

All photos taken by Holly Cope.

A bit about me…

I’m currently a PhD candidate at Sydney University studying under the supervision of Dr Catherine Herbert, examining the use of contraception in the management of endangered species. Most of my work has been on Tasmanian Devils in the Devil Facial Tumour Disease (DFTD) free insurance population. We are using contraception on selected female devils based on their genetics with the aim of maximising genetic diversity, and only giving females which have not yet reproduced or are genetically under-represented the chance to breed. This also lets us keep them housed in groups, which helps to stop them from adapting to captivity, while keeping a mixture of breeding and non-breeding females in with males. This is the best way to make the most of limited resources and housing space in the conservation program.

Holly Cope with a Western Barred Bandicoot.

Why am I using contraception on burrowing bettongs?

My project at Arid Recovery examines another way of using contraception on endangered species. Burrowing bettongs are excellent breeders, and with the removal of most predators, have become locally overabundant within the reserve, with around 8 thousand individuals living inside the fenced enclosure. They are damaging the vegetation and overrunning the other species housed in the reserve, so Arid Recovery is keen to reduce their population to a more manageable size in an ethical and cost-effective way. Fertility control using contraceptive implants is one of the options being considered, but we need to figure out a few things first – does the Suprelorin® implant work on female bettongs? How long will it last? Are there any negative side effects? How many would we need to implant to have an impact on the population? Is this a feasible option logistically and economically?  I aim to answer these questions with a pilot study on around 50 female bettongs in the 1st expansion of the reserve.

Burrowing Bettong in a cage trap.

How does it work?

The Suprelorin implant gradually releases a gonadotrophin-releasing hormone (GnRH) agonist called deslorelin as it dissolves. The continuous release of deslorelin affects the pituitary gland, and stops it from releasing follicle stimulating hormone (FSH) and luteinising hormone (LH), which are both responsible for ovulation. Without FSH and LH, the bettongs will be unable to ovulate and shouldn’t conceive any offspring for some time.

How did it go?

Over 10 nights in August 2017 I set traps with the help of my volunteer, Lachlan, in the late afternoon, checked them after sunset and then reset them for checking again at sunrise. We set and checked traps 408 times and captured bettongs 347 times. We identified 119 individuals (48 females and 71 males), and treated 30 females with contraceptive implants.

For every bettong that we captured, we gave them ear tags if they weren’t already tagged, measured their head and pes (foot) lengths as indicators of age, checked their body condition score and measured tail width as indicators of condition. We also checked their gender and then either measured testes width or checked the reproductive status of the pouch. The boys didn’t appreciate that in the cold mornings! We had four females with small joeys less than a week old, a few others had young at foot and most others had recently weaned a joey. We injected contraceptive implants in 30 females overall (our minimum target), leaving every third untreated to act as a control in the study (to compare the final results against the contracepted females). We had hoped to treat 50 females, but we found a 2:1 ratio of males to females in traps which made it difficult to catch enough!


Injection of the conctraceptive implant, Suprelorin®, under the loose skin between a bettong's shoulders.

We also found a few other mammals enjoying the peanut bait ball! We microchipped and health checked a bilby and a few western barred bandicoots, and released some Spinifex hopping mice and plains mice. We spotted a shingleback and a bearded dragon out sunning themselves too which was quite a treat!

A gorgeous Greater Bilby being processed.

Where to now?

I will be returning every 2-3 months over the next 12 months to re-trap the females in the study and check inside their pouches. Bettongs are able to mate while their current joey is still in the pouch, and this new embryo enters suspended animation (embryonic diapause) until their joey leaves the pouch. This means that some bettongs may have already conceived a new joey before contraception, which we can work out by figuring out the birth date of their next joey. We hope to see no new pouch young conceived after contraception. We will also be monitoring for any weight gain, which can be a common side effect of contraception. The information generated through this project will be given to Arid Recovery managers to help them decide on a course of action for reducing and then maintaining the bettong population at a more sustainable density. If the bettongs appear to still be contracepted at the end of the 12 months, monitoring may be continued by Arid Recovery staff/interns to see when the bettongs begin breeding again. The findings from this research will also be relevant to other reserves housing bettongs or small marsupials that may be facing similar issues.

What a beautiful place to work!

        

  

 

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