Management of invasive mesopredators in the Flinders Ranges, South Australia: effectiveness and implications
Stobo-Wilson, AM and Brandle, R and Johnson, CN and Jones, ME, Management of invasive mesopredators in the Flinders Ranges, South Australia: effectiveness and implications, Wildlife Research, 47 pp. 720-730. ISSN 1035-3712 (2020) [Refereed Article]
Context. Significant resources have been devoted to the control of introduced mesopredators in Australia. However, the
control or removal of one pest species, such as, for example, the red fox (Vulpes vulpes), may inadvertently benefit other
invasive species, namely feral cats (Felis catus) and rabbits (Oryctolagus cuniculus), potentially jeopardising nativespecies recovery.
Aims. To (1) investigate the impact of a large-scale, long-term fox-baiting program on the abundance of foxes, feral cats
and introduced and native prey species in the Flinders Ranges, South Australia, and (2) determine the effectiveness of a
short time period of cat removal in immediately reducing feral cat abundance where foxes are absent.
Methods. We conducted an initial camera-trap survey in fox-baited and unbaited sites in the Flinders Ranges, to
quantify the impact of fox baiting on the relative abundance of foxes, feral cats and their prey. We then conducted a
secondary survey in sites where foxes were absent, following an intensive, but short, time period of cat removal, in which
40 cats were shot and killed.
Key results. No foxes were detected within baited sites, but were frequently detected in unbaited sites. We found a
corresponding and significant increase in several native prey species in fox-baited sites where foxes were absent. Feral cats
and rabbits were also more frequently detected within baited sites, but fox baiting did not singularly predict the abundance
of either species. Rather, feral cats were less abundant in open habitat where foxes were present (unbaited), and rabbits
were more abundant within one predominantly open-habitat site, where foxes were absent (fox-baited). We found no effect
of short-term cat removal in reducing the local abundance of feral cats. In both camera-trap surveys, feral cat detections
were positively associated with rabbits.
Conclusions. Long-term fox baiting was effective in fox removal and was associated with a greater abundance of native
and introduced prey species in the Flinders Ranges. To continue to recover and conserve regional biodiversity, effective
cat control is required.
Implications. Our study showed fox removal has likely resulted in the local release of rabbits and an associated increase
in cats. Because feral cat abundance seemingly fluctuated with rabbits, we suggest rabbit control may provide an
alternative and more effective means to reduce local feral cat populations than short-term removal programs.