Spot our newest members of the Arid Recovery family

Kimberley Solly - Wednesday, September 23, 2015

Under the darkness of the night on May 6th two female Western Quolls (Dasyurus geoffroii) were released into the Arid Recovery Reserve. Koombana and Sepia (named after WA shipwrecks) were wild caught from Menjimup and Julimar respectively in Western Australia and were among 37 other quolls who travelled to the Flinders Ranges, where quolls are currently being re-introduced. They had already travelled a lengthy journey from Western Australia including a 9 hour flight to Wilpena Pound and a 4.5 hour drive to Roxby Downs. These nocturnal carnivores were released at night to minimise stress levels and to maximise the period available to familiarise themselves with their new home.


Sepia captured outside her burrow in the release pen on night 3. Credit: Bec West

The Western Quoll or chuditch as it’s known in Western Australia is one of four extant species of quoll found in Australia. There are also two other living quoll species found in Papua New Guinea! Some refer to quolls as native cats, as they are medium sized carnivores with males of the Western Quoll species weighing up to 1.3 kg, while females weigh up to 900 g. Quolls have a distinctive coat which is rusty-brown to grey colour with the Western Quoll having up to 60 whitish spots along their body, but none on their tail.


Koombana and Sepia are being used as native in situ predators as part of the current Australian Research Council Linkage project with the University of NSW to see if they can improve the anti-predator responses in our re-introduced mammals (Burrowing Bettong, Greater Stick-nest Rat, Western Barred Bandicoot and Greater Bilby). Three of the four re-introduced species at the Arid Recovery Reserve were extinct on mainland Australia and the primary reason for their demise and difficulty re-introducing them outside of fenced reserves is that they have an inability to mount effective anti-predator responses (Moseby et al. 2011). The ARC project aims to improve the survival of native mammal species by exploring prey naivety to introduced predators (cat) and trialing native predators (quolls) as a means of improving anti-predator responses.

Whilst Arid Recovery isn’t looking to re-introduce Western Quolls just yet, Koombana and Sepia are pioneers of a potential future re-introduction. A long term goal of Arid Recovery has been to re-introduce a native predator to moderate herbivore populations and reflect a natural ecosystem. While we have reptile and bird predators, we are yet to return any mammalian predators to the Reserve. The ARC Project Officer Bec West will be closely monitoring Koombana and Sepia for the first 10 months, whereupon a review of the trial will decide whether the quolls are having a detrimental impact on the threatened species within the Reserve. If they are found to be having a negative impact on populations they will be relocated to the Flinders Ranges with the rest of the newly formed quoll population, if not they will be left in situ to form part of a longer term study at the Arid Recovery Reserve.


Sepia having a health check-up! Credit: Kaarissa Harring-Harris

To survive quolls require about 104-140 g of food per day, feeding primarily on invertebrates and opportunistically on mammals, birds, and reptiles (Gaikhorst 2008; Glen et al 2010; Orell and Morris 1994). Historically Western Quolls would have likely been important predators in the arid zone, controlling populations of invertebrate and vertebrate prey species. Trialing the release of quolls into Arid Recovery is the beginning point for detecting potential impacts that may result from returning a native predator to the ecosystem.

Koombana and Sepia have settled nicely into the Reserve, stay tuned to find out how we know what the quolls are eating! 


Written By: Kimberley Solly, Scientific and Education Officer


References:

Gaikhirst, G. (2008). Chuditch Animal Management Guidelines Perth Zoo. Perth.

Glen, A.S., Wayne, A., Maxwell, M. and Cruz, J. (2010). Comparative diets of the chuditch, a threatened marsupial carnivore, in the northern and southern jarrah forests, Western Australia. Journal of Zoology 282, 276-283.

Moseby, K.E., Read, J.L., Paton, D.C., Copley, P., Hill, B.M. and Crisp, H.M. (2011) Predation determines the outcome of ten reintroduction attempts in arid South Australia. Biological Conservation DOI information: 10.1016/j.biocon.2011.08.003, 3-SEP-2011

Orell P. and Morris K. (1994). Western Australian Wildlife Management Program No. 13.  Chuditch Recovery Plan 1992-2000 Western Australian Department of Conservation and Land Management. Wanneroo.


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.

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