Kyle Brewer was selected to receive a cash grant in the latest round of SSAA Bursary awards. Here, he expands the thinking behind his ambitious project that grabbed the attention of the SSAA panel.
The threat foxes and feral cats pose as invasive predators of native Australian animals has been known since the early 1920s. These marauders are largely responsible for the extinction of 28 (11 per cent) of Australia’s known land mammal species and their continued predation is expected to cause the extermination of at least one to two species every decade.
Without effective means of intervention, mammal (as well as bird and reptile) losses will continue and there will be no preventing future extinctions. Currently no ‘silver bullet’ exists for invasive predator control and multiple containment methods are often employed together (eg, poison baiting, trapping, shooting). Poison baiting is the most effective invasive predator control process and can significantly reduce their numbers. However, in many cases individuals that don’t consume poison baits (‘bait-shy’ animals) persist within the target area and inflict considerable damage on native mammal populations.
This is particularly relevant in reintroduction areas, where attempts are being made to establish small captive-bred populations of native animals in the wild, as bait-shy predators have been known to wipe out entire blocks of reintroduced animals. My PhD research aims to complement current control strategies like poison baiting through the development of innovative control technologies, with the overall aim of improving efficacy. These improved control means can then be used as ‘tools’ within a ‘conservationist toolkit’ that can be tailored to specific instances of exotic predator curbs.
Foxes and feral cats possess a keen sense of smell and investigate sources of odours that are novel or associated with food sources. My project aims to take advantage of this and involves the development of an olfactory lure that mimics the odour of a native animal and is designed to attract foxes and feral cats.
The lure is unpalatable and therefore, through behavioural conditioning it is hypothesised the predator will associate the odour as a non-food source and eventually become immune to the effects of the smell and ignore it completely.
Similar behaviour is well recognised in humans and is related to sensory adaptation. Imagine you enter a room and inhale the scent of fresh flowers in a vase. If you remain in that room your brain will start to perceive a decrease in the scent’s intensity over time (the smell seems to fade) even though the intensity of the aroma actually remains constant. This sensory adaptation is our brain recognising the smell is not dangerous and reducing our sensitivity to it to exclude redundant information.
Ultimately we hope the unpalatable olfactory lure will prove useful for native animal reintroduction programs. Many such projects involve the breeding of animals in captivity followed by the release of the population into the wild. However, before this can happen the intended reintroduction area needs to be cleared of foxes and feral cats through various control initiatives, which can be very costly as well as time and labour intensive.
In addition, the predators may migrate in and out of the area meaning they’re missed. Our alternative solution to this problem is to spread the unpalatable olfactory lures across the intended reintroduction area and allow foxes and feral cats to investigate the odours for several weeks. The lures are designed to smell like the native animal that’s going to be reintroduced so foxes and cats gradually become conditioned to ignore the odour (through sensory adaptation) and recognise it as being inedible.
Once the predators have been conditioned, the native animals can be introduced into the area in the hope they will also be ignored and therefore have a much greater chance of survival.
Assistance kindly provided by the SSAA’s Academic Bursary Program will allow me to travel to the ACT, deploy the olfactory lure in field trials and test this hypothesis within a controlled reintroduction area.
I thank the SSAA for supporting my ongoing research and also backing the fight to conserve our endangered native Australian animals.
Meg Edwards is another student who benefitted from the SSAA Bursary awards. She has taken time to expand on the thinking behind her initiative.
Native wildlife in Australia has faced devastating effects from introduced predators such as feral cats and foxes. More than a quarter of our mammals have become extinct in the past 220 years and Australia now has the world’s worst mammal extinction record. In particular, many of our bandicoots and bilby species are facing extermination from these introduced killers.
Australia has approximately 20 species of bandicoots with many under threat. By training our wildlife to avoid predators, bandicoots may have a fighting chance of survival. The northern brown bandicoot is an omnivorous species weighing between one and two kilograms and very common in gardens, although often people only see their iconic diggings. Northern brown bandicoots are an ideal species to use as a model for endangered groups such as the greater bilby.
As part of my PhD research, bandicoots are captured from the wild and brought to the Hidden Vale Wildlife Centre, a new research unit in south-east Queensland. There, the bandicoots are tested to see how they react to introduced predators then an attempt is made to train them to run into safe bandicoot bunkers.
These bunkers are controlled by microchip automation so only microchipped bandicoots can have access and are safe from predators. The bandicoots are trained to use the microchip-automated bunkers by enticing them with a piece of bread with peanut butter on ‑ the bandicoots’ favourite treat! The bunkers can also be an area where bandicoots could be given supplementary food in the wild after release, as they don’t allow access unless the microchip has been registered to the door. So it excludes any potential competitors as well as predators. All this training (to use the bunkers and predator-avoidance schooling) is captured on video and the footage studied to determine the bandicoots’ behaviours such as vigilance, foraging and movement habits.
Once trained, the bandicoots are released back into the wild and tracked to determine their reintroduction success. VHF transmitters are attached to the bandicoots and either myself or a volunteer goes out daily to find them and obtain a GPS location. This data is used to see if the predator-avoidance training had an effect on their survival after release. It’s hoped information gained from this research can help reintroduction projects around Australia, so I thank the SSAA for their financial support which helped fund the cameras used to capture the video material.
Caitlin Ford will use funding from the SSAA Academic Bursary program to pursue her post-graduate studies into teaching predator avoidance skills to two of Australia’s native species.
Caitlin, 25, arrived from her native England a year ago after securing a place at the University of Queensland where she’s undertaking a four-year full-time Wildlife Conservation course. Her specific project involves predator avoidance training via microchip automated devices linked to the yellow-footed antechinus and eastern chestnut mouse.
The yellow-footed antechinus is a shrew-like marsupial whose territory stretches from the Mount Lofty Ranges in South Australia to Eungella in Queensland, with the exception of most of coastal New South Wales and Victoria. The eastern chestnut mouse is found along the eastern coast from northern Queensland and into NSW as far as Jervis Bay.
The mechanisms are used on both species in captivity and monitor their behaviour during predator avoidance training and are then continued when the animals are reintroduced to their original habitat. The ingenious scheme utilises microchip automated doors attached to custom-made nest boxes placed inside enclosures prior to the animals arriving from the wild. The interactions of the animals are recorded using infrared remote surveillance video cameras then the behaviour analysed.
SSAA Bursary directors awarded $1996 which Caitlin will use to cover equipment fees, broken down into $880 for microchip automated doors, $1026 for microchips and $90 for predator avoidance training resources.
Her research is building on similar investigations carried out by another SSAA Bursary recipient, Megan Edwards. “It’s a comparison between two species to see which ones can recognise and avoid invasive species such as cats, red foxes and wild dogs,” said Caitlin. “It’s following on from Meg - trying to find if various animals’ personalities affect their ability to act.”
Caitlin will spend some of her funding to buy the nest boxes and use them with the animals in captivity before transferring them to the wild. “They’re automated doors just like pet doors for cats and dogs,” she said. “We’ll teach the animals in captivity and use them as nest boxes, see how long it takes and work out if they use them in the wild. We can also put food in the boxes to sustain them when conditions become harsh.”
Caitlin’s research is carried out at Hidden Vale Wildlife Centre, west of the main University campus in Brisbane. She has two to three years left to complete her course when she’ll hopefully graduate as a Doctor of Philosophy. “There are various subjects which go under the umbrella of philosophy with mine being conservation,” she said.
It has been an enthralling academic journey so far and she’s enjoying the ride after moving from her home town of Epsom in Surrey to carry out her undergraduate studies at Southampton University where she earned a Masters ranking.
“I started in zoology but switched to ecology during the course,” said Caitlin. She may be a long way from home but is relishing the experience. “I’d never been to Australia but what better place to could there be to carry out conservation studies?”
She also finds time for some teaching duties around conservation. “I love the teaching aspect and depending on securing the required visa, I’d like to stay in Australia,” she said. “It’s a wonderful opportunity - research here is very innovative whereas back home it’s more traditional.” Hopefully the SSAA Bursary grant will go a long way to helping Caitlin realise her ambitions.