Two alternate states: shrub, bird and mammal assemblages differ on either side of the Dingo Barrier Fence

Abstract

The 5500 km long dingo barrier fence (DBF) is a boundary at which the goal of dingo control programs shifts from management to elimination. Since 1980 ecologists have used the discrepancies in dingo densities across the DBF to study the ecological role of Australia’s largest terrestrial predator. We used drone imagery, ground based shrub and tree counts, and camera trap footage to test our hypothesis that there are alternate states in plant, bird and mammal assemblages on either side of the DBF. We found that shrubs and trees were twice as dense where dingoes were rare, and 28 % of shrub and tree species, 78 % of mammal species, and 14 % of bird species recorded were significantly more likely to occur on one side of the DBF than the other. We provide the first comprehensive snapshot of how flora and fauna assemblages differ across the DBF. This study adds to literature demonstrating that the removal of the dingo has led to profound shifts in the shrub, mammal and bird assemblages in arid Australia. Any expansion of dingo control in arid Australia must be considered against the far-reaching consequences for ecosystem assembly associated with the removal of a top predator.

Differential developmental rates and demographics in Red Kangaroo (Osphranter rufus) populations separated by the dingo barrier fence

“…The Quinyambie property (30°21ʹ43″S, 140°41ʹ46″E) is to the north of Mulyungarie, also bordered to the east by the State boundary. While dingoes are present on both properties, the densities differ greatly so that dingoes are considered common in Quinyambie, but rare in Mulyungarie ( Mills et al 2021 ). For brevity, we refer to Quinyambe as ‘dingoes-common’ and Mulyungarie as ‘dingoes-rare’ in the analysis and interpretations.…”

“…Over the last decade, many studies have revealed that the exclusion of an apex predator can substantially alter ecosystem balance and function on either side of the dingo barrier fence. For example, dingo exclusion by the fence has been linked to shifts in the structure of mammalian communities ( Letnic and Koch 2010 ; Rees et al 2019 ; Mills et al 2021 ), ground-dwelling marsupial extinctions resulting from increases in mesopredator abundance ( Johnson et al 2007 ), and changes to floral assemblages ( Gordon et al 2017 ; Rees et al 2017 ; Fisher et al 2021 ). These effects have elicited far-reaching trophic cascades, and also altered soil nutrient profiles ( Morris and Letnic 2017 ) and landscape geomorphology ( Lyons et al 2018 ).…”

Habitat associations of dryland avian communities during an extended dry period

“…During an extended dry period in our study, avian communities did not differ across the two management regimes: Sturt National Park, without dingoes and cattle; and adjacent pastoral properties, managed for cattle grazing with dingoes present. This was despite differences in vegetation structure and ecosystem functioning (Gordon et al, 2015; Letnic et al, 2011; Mills et al, 2021), and previously reported differences in bird communities across the dingo‐barrier fence (Gordon et al, 2017; Rees et al, 2017; Rees, Kingsford, et al, 2019; Rees, Rees, et al, 2019). Extreme resource limitation and resultant low overall abundances likely drove this pattern, which may indicate a case of trophic switching from top‐down to bottom‐up regulation (e.g.…”

Terrestrial mesopredators did not increase after top-predator removal in a large-scale experimental test of mesopredator release theory

“…3) and is not particularly noteworthy. Moreover, and despite being a common way of searching for and claiming evidence of mesopredator releases (for examples, see 24,26,[71][72][73] ), such simplistic and correlative comparisons of overall mean PTI between treated and untreated areas cannot and do not elucidate any causal processes and hence cannot be used to make inferences about dingo control-induced mesopredator release 45 (but see also [53][54][55][56][57][58][59][60][61][62] ).…”