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 here, here 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