By Andrew Howe, Senior Field Ecologist and Christine Mauger, Field Ecologist
Australia’s largest wombat – the Yaminon or Northern Hairy-nosed Wombat (Lasiorhinus krefftii) – only lives in two small populations in outback Queensland, with the total world population being just 315 individuals. Despite these relatively small numbers, this is a remarkable conservation success story led by QLD Department of Environment and Science (DES), as the species was reduced to as few as 30 individuals in 1982.
Australian Wildlife Conservancy (AWC) is a new partner in the DES-led Northern Hairy-nosed Wombat Recovery Program – supported by The Wombat Foundation – and collaborative efforts will continue to conserve Northern Hairy-nosed Wombat habitat and boost numbers of this Critically Endangered species. This year has seen multiple field trips into Northern Hairy-nosed Wombat territory: AWC ecologists have assisted with population censuses at Richard Underwood Nature Refuge (RUNR) and at Epping Forest National Park (Scientific); undertaken a caretaker role at RUNR in October; and surveyed part of the species’ historical distribution to find additional suitable habitat.
Northern Hairy-nosed Wombat trapping at RUNR
In late April, two AWC ecologists travelled over 1,500 kilometres from their tropical base in Cairns to RUNR in chilly south-central Queensland. It is here that the smaller of the two Northern Hairy-nosed Wombat populations resides. For the first time, a refuge-wide census of an estimated 15 animals was attempted by DES staff, AWC ecologists and volunteers. AWC helped with health assessments, genetic sampling and fitting some individuals with GPS collars.
After an extended drought, the region where the nature refuge is located has received above average rainfall for the past three years and the landscape is responding dramatically with a flush of new growth. These conditions have allowed the wombats to gain weight, and those trapped recorded almost perfect health scores. With such an abundance of food around, it made trapping wombats incredibly challenging. Conditions were not on our side with unseasonal rain – who wants to leave a cosy and warm burrow to go out in the wet? – and only four individuals were captured.
Unlike most wildlife, Northern Hairy-nosed Wombats do not respond to food baits, so large, custom-built traps are placed at their burrow entrances in the hope that individuals will be captured upon exiting. The challenge lies in the fact that happy, healthy and round-bellied wombats can easily wait out even the most dedicated ecologists until we give up and move our traps elsewhere. When we were lucky enough to catch one, it was an amazing experience to witness these ‘bulldozers of the bush’ up close. Some of the bigger individuals measured over one metre in length and weighed up to 32 kilograms!
Censuses and caretaking
In September, AWC ecologists headed to Epping Forest National Park (Scientific) in central Queensland where the larger of the Northern Hairy-nosed Wombat populations resides. Here, we assisted DES staff in undertaking a ‘hair census’. Double-sided tape was placed across the entrance of each burrow, collecting hair samples as the wombats moved about. From these samples, DNA will be extracted, allowing individual animals and their sex to be identified. This simple, non-invasive technique is incredibly useful as a means of obtaining population estimates for a species that is notoriously difficult to study in the wild.
Over the month of October, AWC ecologists returned to RUNR to conduct the caretaker role. This has allowed AWC scientists to gain a better understanding of the property, the wombats and their habits. The caretaker role involves maintenance of the predator-proof fence, the removal of targeted weed species, monitoring camera traps and downloading and collating data, daily tracking of wombats fitted with GPS collars and recording activity levels around burrows.
As part of the collaborative project to secure the species, AWC is working to acquire additional property that has habitat suitable for Northern Hairy-nosed Wombats. The challenge is that the species has very specific soil type and depth requirements – deep sandy loam or sandy clay soils to a depth of at least 2.5 metres. This allows the wombats to dig their burrows deep enough to stay cool in the hot summer months and warm over the cool winters.
Excitingly, AWC ecologists and soil scientists have now inspected a property within the species’ known historical range that has the required habitat to potentially sustain a large population. AWC is committed to supporting the recovery of the Northern Hairy-nosed Wombat – one of the world’s most endangered mammals – and, although still only in the early assessment phase, this is potentially a positive step for their conservation.
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