Document ID: chunk:federal_register_of_legislation:F2024L01747:reg:4:p19
Version: federal_register_of_legislation:F2024L01747
Segment Type: reg
Provision Reference: reg 4 (pt 19/80)
Character Range: 56699–59685

cat impacts?

Population declines and local extirpations of native animal species due to cat predation may compromise the healthy functioning of ecological communities, and potentially even their structure and composition. For example, many of the native mammal species that are now extinct or missing from most of their previous (and in many cases, extensive) range were prodigious diggers, with their turnover of soil and litter having substantial beneficial effects on decomposition rates, nutrient and water cycling, seed spread and germination, plant recruitment patterns and fire regimes. The ecological consequences of loss or reduction in the services provided by cat-susceptible mammal species have probably had, and continue to have, detrimental impacts on some threatened ecological communities; however, this is not yet explicitly documented for any of those communities.

Given the types of species that are most susceptible to cat predation, and the ecology and behaviour of cats, the ecological communities most adversely affected by cats are probably those that: are structurally simple; occur in arid and semi-arid areas or on islands; contain keystone animal species that are ground-dwelling and within the preferred prey size range for cats (i.e. less than 4 kg); have vegetation structure which is heavily transformed by fire; and are heavily affected by fragmentation.

     4.1.3 Factors that amplify cat predation impacts

The threat and impact of cat predation is moderated or compounded by other factors, including co-occurring threats. Some examples are briefly listed here.

Abundant populations of rabbits Oryctolagus cuniculus and introduced or native rodents (especially house mouse Mus musculus) support higher densities of feral cats, which can result in higher predation pressure by cats on native species. The risks to native animals from these 'inflated' cat populations can be acute when sudden reductions in primary productivity (e.g. a return to dry conditions after prolonged rainfall) cause rabbit or rodent populations to crash, forcing cats to switch to alternative prey species.

Changes to the fire regime or to grazing pressure that simplify the structural complexity of the ground layer may worsen the predation risk to ground-dwelling animals. This is partly because cats are drawn to hunt in, or along the edges of, recently burnt areas (especially if those areas contained high native prey density before the fire), and because the success of hunting attempts by cats increases in open areas.

Habitat clearing and fragmentation may increase predation risk, because cat density can be higher in the modified habitats surrounding the fragmented remnant vegetation, and cats may target the fragments, or their edges, for hunting. Because of these interactions, the level of cat control and management needed to protect native species will vary, depending on the context.

Cat density, activity / behaviour or impacts may be affected by the