Few have heard of it and even fewer have seen it, but the wiliji (Petrogale lateralis kimberleyensis) is very much on WWF's radar.
This West Kimberley black-flanked rock-wallaby or wiliji, listed as endangered in Western Australia, is found in only three isolated ranges in the Kimberley region of northern Australia. A population once thought to be 2,500 strong has plummeted to an estimated 500, and this gorgeous creature could easily become extinct within a decade. WWF’s assessments supported uplisting this West Kimberley subspecies of rock-wallaby to endangered.
But the Traditional Owners of this region, the Nyikina Mangala people, recall a time when the wiliji was more plentiful on the cliffs and escarpments of their homelands. A time before the arrival of feral cats and foxes, and the livestock that compete for food, and the indiscriminate wildfires that degrade the wiliji's restricted habitat. So, who better to protect the wiliji than those who know its lands best?
Since 2011 we've been working with the Nyikina Mangala Rangers to give the wiliji every chance of survival in the Grant, Edgar and Erskine Ranges. Our surveys of this remote country are providing vital information on these three distinct wiliji populations, searching for new populations by helicopter, plus remote-sensing cameras and surveys with thermal-imaging drones are capturing never-before-seen images of this rare animal.
Like the four other subspecies of black-flanked rock-wallaby, the wiliji is secretive and usually only emerges from the safety of its rocky refuge at night to dine on nearby vegetation. By conducting controlled burns early in the dry season, Nyikina Mangala Rangers are keeping fuel loads down and protecting the wiliji's larder from the more destructive, intensive wildfires that can ignite late in the season.
We have also partnered with the Nyikina Mangala Rangers to undertake ground-breaking research to discover which plants wilijis eat, so that we can be even more targeted in our recovery efforts. Using new technology known as eDNA or Environmental DNA Analysis, we’ll be able to detect all of the unique DNA of individual plant species contained in wiliji scats (poo) collected by the rangers, which will provide us with a list of plants eaten by the wiliji. Once we know what plants the wiliji eat, the Nyikina Mangala Rangers will be able to use fire and cattle fencing to protect the wiliji’s food, while also promoting the growth of more food plants by giving nature the helping hand it needs!
Bringing the wiliji back from the brink is going to demand a Herculean effort. These unique animals still face threats such as feral predators, introduced herbivores, large bushfires and small population size. More information is still needed for us to win the fight against extinction.
But out of sight is definitely not out of mind. By combining age-old local knowledge and expertise with modern technology, we hope to protect the wiliji for generations to come.
WWF-Australia thanks the significant support of many organisations with respect to our work on wiliji, including the Walalakoo Aboriginal Corporation. Our work would not be possible without the financial support of Lotterywest and WA’s State NRM Program.