Document ID: chunk:federal_register_of_legislation:F2022L00195:reg:4:p1
Version: federal_register_of_legislation:F2022L00195
Segment Type: reg
Provision Reference: reg 4 (pt 1/8)
Character Range: 43358–46421

4               Threats

4.1                 Historical causes of decline
Historically, the major cause of decline of the Mahogany Glider was habitat loss as a result of large-scale clearing of lowland open woodlands for agriculture (including sugar cane, bananas, pineapples and aquaculture), roads and residential developments (Jackson et al., 2011). The extent of Mahogany Glider habitat has decreased from an estimated 276,880 ha, before broad scale clearing began, to 141,122 ha by 2007 (a total reduction of approximately 50%) (Jackson et al., 2011; see Map 1). The Mahogany Glider is now restricted to the foothills of the ranges and pockets of fragmented habitat in coastal and lowland areas throughout the extent of its range (Jackson et al., 2011).

4.2                 Current known threatening processes

4.2.1             Habitat loss and fragmentation
While broadscale clearing of habitat has largely abated, incremental loss of habitat still occurs particularly through changes in land use. For example, subdivisions of freehold and leasehold properties resulting in reduction in overall parcel size typically results in intensification of land use including:
    * Clearing of vegetation for more intensive types of agricultural activity.
    * Clearing of vegetation for the construction of new residential and management buildings.
    * Clearing of vegetation for new roads, tracks, fire breaks and fence lines.
    * Clearing of vegetation for new electricity supply lines and telecommunication cabling to new residential and management infrastructure.
    * The erection of new boundary and internal fences.
The continued loss of habitat exacerbates the reduction in the total area and condition of Mahogany Glider habitat, creates new linear barriers, and reduces the movement of Mahogany Gliders through the landscape. New barbed wire fences add further to the threat of entrapment posed by existing barbed wire fences as a significant cause of death for this species.
It is also recognised that Material Change of Use (MCU) applications can be associated with a change of land use to a more intensive use including more intense agricultural use (including aquaculture), resort developments, and subdivision for rural and urban residential developments. MCUs typically lead to impacts similar to those highlighted for Lot Reconfigurations.
The remaining habitat of the Mahogany Glider is highly fragmented with mapping studies suggesting there are 998 habitat fragments. Of these fragments, only 5 are greater than 8,000 ha, which is the minimum area required to maintain a stable population (Jackson, 1999; Jackson et al., 2020). Consequently, there is a critical need to connect these fragments with corridors to allow the movement of animals and increase their effective population size (Jackson, 1998; 1999; Jackson et al., 2020). Therefore, future conservation actions must ensure that the remaining fragments of habitat are managed appropriately to ensure they are large enough to maintain viable populations of gliders and adequately