By Tim White, Regional Operations Manager, Josh McAllister, Sanctuary Manager, Felicity L'Hotellier, Senior Field Ecologist and Dr Alexander Watson, Regional Ecologist
After almost two decades of considered stewardship at Mount Zero-Taravale Wildlife Sanctuary, Australian Wildlife Conservancy (AWC) is on the cusp of a translocation that will result in securing a new population of the extremely rare Northern Bettong in the diminishing tall wet eucalypt forests of north-east Queensland.
The well-documented absence of the Northern Bettong from its historical range in this area has informed the core of investment by AWC in a land management strategy of habitat rehabilitation. Removal of cattle, implementation of frequent and diverse prescribed burning, and manual and mechanical thinning of understorey woody weeds and vegetation in the wet sclerophyll forests are helping to rewind the clock on the regional trend of habitat loss.
AWC monitoring of indicator animal and plant species has found the strategy is working - halting woody thickening and restoring the grassy understorey among the tall forests which provide critical food and refuge for the Northern Bettong. But the last and most significant component of securing the future of the species - shared by so many small- to medium-sized mammals across Australia - is protection from feral predators, particularly cats. Since their introduction, cats have spread to occupy more than 99% of the continent and every night kill more than six million animals. Juvenile Northern Bettongs are particularly vulnerable to predation by these introduced predators.
Wayne Lawler/AWC Planning the first feral predator-proof fence in northern Australia
Adjacent to the Wet Tropics World Heritage area, the north-eastern part of Mount Zero-Taravale consists of rugged topography, steep elevations between 1,000 and 700 metres, annual average rainfall over 2,000 millimetres and rainforest-fringing tall eucalypt forests with trees up to 75 metres high, all in a cyclone region. This is a formidable combination of terrain, climate and forest in which to build the first feral predator-proof (exclusion) fence in northern Australia. The challenges the team face are unprecedented, but initiative and dedication are values entrenched in the conservation model delivered by AWC.
Over the last four years, a digital representation of a 13-kilometre fence line, encompassing an area of approximately 1,000 hectares of tall eucalypt forest, has been checked on the ground and painstakingly adjusted for what was intuitively considered a path of least resistance.
Wayne Lawler/AWC Late in 2020 - amongst the challenging social and travel restrictions of COVID-19 - Gugu Badhun Traditional Owners, Sanctuary Manager Josh McAllister, Senior Field Ecologist Felicity L'Hotellier, Land Management Officer Aaron Harper and other regional ecologists and botanists surveyed the fence line for Indigenous cultural heritage, environmental values and final adjustments of alignment. While vegetation and environmental management legislation was navigated, a physical as well as regulatory pathway was revealed.
With 13 kilometres of fencing materials already purchased and delivered to site, clearing a 10-metre- wide pathway through the forest began in earnest in the second half of 2021 as the northern dry season progressed. The North Queensland vegetation, topography and hydrology challenged the tried and tested AWC fencing design and methodology borne out of many years of delivering a successful conservation model in central and southern Australia.
Professional engineers were contracted to design crossings of waterways accounting for several metres of wet season runoff and considering vehicle access and fence security. These solutions came at a cost that was immediately prohibitive even for the most optimistic and successful philanthropic organisation. The AWC model and values were again apparent as land management experience was tested to find a more traditional solution of floating floodgates and anchors.
Fence construction begins
A modest wet season between 2021 and 2022 provided excellent conditions for settling the ground along the fence line after the first clearing was achieved. Final fence design and the process of finding a contractor began, along with the ongoing application of prescribed burning in the sclerophyll forest. An experienced and familiar face in Mike McFall was eventually awarded the contract to work with AWC land managers in installation of the fence (Mike has been involved in fence construction at AWC's Mt Gibson and Newhaven Wildlife Sanctuaries, at Pilliga State Conservation Area and Mallee Cliffs National Park, and the Western River Refuge). A range of upsizing measures have been employed from the type and size of machinery engaged in vegetation and earth moving, to the size of steel posts around the 13-kilometre fence.
Fencing began in July 2022 with a forecast completion of October/November. Plans for feral animal eradication within the fenced area are also taking shape. A strategy informed by a camera trap grid throughout the exclusion fence must meet the requirements of the translocation agreement with the QLD Department of Environment and Science, specifically the eradication of feral pigs, feral cats and cattle.
Sally Gray/AWC The project makes a major contribution to saving the Endangered Northern Bettong from extinction and continues to break new ground in many facets of the AWC conservation model of exclusion fencing. The challenges the team face in building and maintaining this safe haven in a cyclone region are unmatched - when, more than ten years ago, a cyclone hit Mount Zero-Taravale it took sanctuary managers a week to cut themselves a driveway to get to the main road. These challenges will be met with initiative, dedication, resilience and tenacity from the AWC team. Support from the Australian Government, the Oak Foundation, WIRES, AWC US, and donations from generous supporters around the world have helped make this ambitious and challenging project an exciting reality.
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