Nabarlek caught on sensor camera from surveys in the Kimberley © University of New England / WWF-Aus

Nabarlek caught on sensor camera from surveys in the Kimberley © University of New England / WWF-Aus

Nabarlek

Little is known about the secretive nabarlek, one of Australia's smallest species of rock-wallaby. But it’s thought to be on the brink of extinction, surviving in possibly just a few sites in the Northern Territory.

As nabarleks are difficult to distinguish from some other species, only specimens or faecal DNA can be used to ascertain their presence. In the western NT, a subspecies known only from one specimen, collected back in 1839, is now thought to be extinct. The Arnhem Land subspecies has declined markedly since European settlement with absences reported from sites where nabarleks were previously recorded. And in the Kimberley, a third subspecies was considered relatively widespread before WWF-led surveys in 2013 and 2015 found that it may be limited to just one offshore island . In any case, the nabarlek is in dire straits.

What makes studying – and protecting – the nabarlek so challenging is that it occurs in remote parts of the country. Add to this the fact that it’s very similar in appearance to the monjon and juvenile short-eared rock-wallaby, and you have one tricky research subject. Genetics or skull morphology are the only sure-fire ways to identify it. WWF helped to pioneer a new method for distinguishing these species and now we're funding the genetic analysis of museum specimens.

What WE'RE doing

View our projects involving nabarleks.

Nabarlek caught on sensor camera from surveys in the Kimberley © University of New England / WWF-Aus

Why it matters 

Prior to WWF's surveys, it was assumed that the nabarlek population in the Kimberley was large, widespread and stable. We were therefore horrified to discover that from more than 50 sites surveyed, nabarleks were only recorded on the one offshore island. A tragedy may be unfolding right before our eyes.

If nabarleks are secreted within rocky outcrops and escarpments on the mainland, then we need to find them urgently. We need to assess what threats they face and address those threats without delay. If it has already disappeared from the mainland, the nabarlek's current IUCN and EPBC status must be updated to a higher level of risk of extinction, and the limited number of island animals must be given greater protection.

The remote and relatively undeveloped Kimberley is thought to be a stronghold for native animals, with no extinctions recorded since European arrival. A significant decline in nabarlek numbers would challenge this theory and indicate that more needs to be done to protect this important region.

 

THREATS

  • Fire
  • Introduced predators
  • Climate change
  • We are yet to learn exactly just what has brought the nabarlek to the brink of extinction, but changes to fire regimes since European settlement and predation by feral cats are at the top of the list.

    Habitat degradation due to weed incursions and competition for food and shelter from introduced herbivores, like cattle, have also been blamed. As populations shrink and become more fragmented, nabarleks are also thought to become more vulnerable to climate change.

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