The Kimberley

Mention the Kimberley and visions of spectacular sunsets, giant Boab trees, rocky escarpments and cascading waterfalls spring to mind, but this remote northern region of western Australia is much more than this.

Australia’s Kimberley is roughly the size of Victoria and one of only five great wilderness areas remaining in the world. Geographically, this region stretches north from a line between Broome in the west to the Northern Territory border in the east. It is one of the most ecologically intact regions in Australia, containing exceptional biodiversity, high numbers of endemic fauna and many animals listed as threatened or declining elsewhere in Australia.

There have been few biological surveys of the Kimberley and all have occurred in the high rainfall areas as opposed to the lower rainfall, rangeland regions. We've been undertaking surveys in the lower rainfall regions to establish baseline data on the fauna and flora of the north Kimberley rangelands and to identify biodiversity and ecological hotspots within this region for conservation management.

Survey sites were selected based on geology, soil type and vegetation communities. A variety of fauna survey techniques were employed at each site visited including elliot, cage, and pitfall trapping, harp trapping, spotlighting, scat analysis (hair and bone), cat gut content analysis (smelly job), rock rolling (for reptiles), anabat recording and direct observation.

Survey effort currently totals in excess of 20,000 trap nights with roughly 40 sites surveyed within the two million acre survey area. As there are few roads in the north Kimberley, movement around the region was either via our truck ‘old Ell’, quad bikes, on foot, or if we were very remote, by helicopter.

Fire mapping indicates that roughly half of this two million acre area has burnt each year.  This results in the vegetation becoming very similar type and age. 

To date, our research work in the Kimberley has identified over 170 different bird species and 75 different reptile species including several un-described species (one legless lizard, two skinks, one gecko and one fresh water turtle species), a testament to the rich biodiversity of this region. In addition, we have identified 26 different frog species, including several unidentified species and 50 mammal species.

Extensions to the previously known range of many species have also been documented. Although the variety of different mammals found to date has been amazing, with few exceptions, their density has generally been low. The botanists from the WA Botanic Gardens have fared better, finding and pressing countless previously unidentified species of grasses, forbs and flowering plants.

An urgent need exists to establish good vegetation, fire and maps for this region

Distance, isolation and the inability of foxes and rabbits to take hold in the north protected much of this region of Australia, but many scientists now believe that the tide is turning and we may be on the cusp of the next great wave of extinctions in this country. Likely threats come from a combination of overgrazing by cattle (hard-hoofed stock), changed fire regimes, the introduction of feral donkeys, horses, pigs, cat and cane toads, mining/mining infrastructure (roads, people, towns), disease and climate change.

With our collaborators, Conservation Ark staff are striving to expand our activities in the north Kimberley rangelands including addressing the threats of overgrazing, reducing the extent of late dry season wildfires, identifying biodiversity hotspots within the region and establishing the necessary mapping.

Isolation combined with little development and few people have acted to protect the Kimberley but the tide is turning and we may be on the brink of a wave of extinctions in this country.