By David Nelson, Senior Field Ecologist
AWC ecologists and Dambimangari rangers have recently completed biodiversity surveys on Dambimangari country, which aim to extend our understanding of what animals are present, where they occur, and how populations are faring under the joint management of AWC and Dambimangari. This management includes fire, feral animal and weed control programs that have been carried out over the last two years.
Dambimangari country represents a large proportion of the north-west Kimberley, one of the few parts of mainland Australia with an intact mammal fauna. This land has been actively managed by the Dambimangari people over millennia, and we have their custodianship to thank for its intact natural values. Today, AWC and Dambimangari Aboriginal Corporation (DAC) have partnered to implement best-practice land management, guided by strong science, to deliver conservation outcomes.
Established in late 2017, this partnership is a novel model for conservation on Indigenous land. AWC provides expertise, experience and resources to protect the exceptional conservation values of this land. DAC can achieve its conservation goals while building capability in its ranger group and generating an income.
Establishing a species inventory
The task of producing a species inventory of Dambimangari country is no mean feat. The country covers 800,000 hectares, stretching for more than 200 kilometres end-to-end. The area encompasses 725 islands and 3,000 kilometres of coastline that winds past a seemingly endless landscape of rocky ranges, mangrove forests, tidal and freshwater rivers and dissected sandstone escarpments.
To date, we have focused on identifying threatened species – particularly mammals. There are seven nationally threatened, terrestrial mammal species that may be present on Dambimangari country, plus another 11 listed at state level as ‘priority species’, that are important to monitor and study. Some of these species, like the endangered Northern Quoll (Dasyurus hallucatus), have already been detected. We are optimistic we will find others, like the Brush-tailed Rabbit-Rat (Conilurus penicillatus). Mapping the occurrence of Kimberley endemics, such as the Monjon (Petrogale burbidgei) and Wyulda (Wyulda squamicaudata), is also a priority.
From our work in places like AWC’s Charnley River-Artesian Range Wildlife Sanctuary, we know many important species occur in the sandstone escarpments that are a prominent feature of Dambimangari country.
Accessing this remote country is like a military operation. We deployed 89 baited camera traps over a large area in the south/central part of Dambimangari country, accessing sites either by boat on the coast or by helicopter further afield. Camera traps are an effective tool for identifying the presence of most species, however, to distinguish some species – Golden Bandicoots (Isoodon auratus) from Northern Brown Bandicoots (I. macrourus), and Monjon from Nabarlek (Petrogale concinna) – we need to analyse DNA. For this, we must live-trap the bandicoots, while the rock-wallabies conveniently leave small, round, black DNA samples scattered over the rocks – scats, which we collect for analysis.
Working with DAC rangers, we identified 55 species caught on camera on the recent biodiversity survey, highlighting the exceptional conservation values of this country. In total, 19 mammal, 25 bird and 11 reptile species were identified from more than 1,500 animal detections. The most common species was the endangered Northern Quoll, present at every mainland site surveyed. We also found bandicoots and small rock wallabies at about half the mainland sites surveyed. We are now eagerly awaiting the results of DNA testing.
The picture we are building through these surveys is of a landscape that is bustling with threatened and endemic mammals.
As well as identifying native wildlife, remote cameras give us an idea of the distribution and density of feral animals. The good news is that not a single feral pig, horse, donkey or cow was detected. Only two feral cats were observed, supporting our theory that cats are in low densities here due to the rocky habitat which provides critical refuge for wildlife, and to the history of good fire management, and the absence of feral herbivores.
Searching for species most at risk
The next task is to redouble our efforts to find species most at risk of decline. We are strategically selecting novel habitat types to maximise our chances of discovering new populations of priority species. We are also incorporating factors such as fire history into our site selection, which will help us learn more about how we can best protect the species present here.
AWC and DAC are continuing to work together to co-design an effective model for delivering conservation. Data from the surveys conducted in this initial phase of the project will help us create an EcoHealth monitoring program that will allow us to measure ecological outcomes. Ultimately, the ongoing health of this beautiful and ecologically rich region depends on it.