Testing a simple solution to over-abundance

Kimberley Solly - Tuesday, December 20, 2016

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

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


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

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

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

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

20 years of cat control: keeping threatened species safe

Admin Aridrecovery - Monday, December 19, 2016


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

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

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

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

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

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

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

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

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

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

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

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




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