Predicting bait uptake by feral cats, Felis catus, in semi‐arid environments

Abstract

Summary Feral cat control using aerial broadcasting of toxic baits continues to be used in the rangelands of Western Australia. The effectiveness of these operations has sometimes been compromised by different environmental factors that affect prey and cat numbers. This study demonstrates that the ratio of cats to their preferred prey (small mammals) can be used to predict the most effective time to bait. The regular baiting of three conservation sites offered an opportunity to study the relationship between feral cat abundance, the abundance of their prey and ingestion of toxic baits. Peron Peninsula on the mid‐west coast, Lorna Glen station in the northern Goldfields and the central Gibson Desert of Western Australia are sites where cat control using toxic baits has been routinely applied over the last 15 years. We postulated that bait ingestion by cats was linked to the availability of live prey. Small mammal abundance (capture rates in pit‐fall traps) and relative cat abundance (based on daily track counts) were assessed at these sites and the data used to produce a predator‐prey ratio index (PPRI). We used generalised linear mixed models to test the effect of prey abundance, prebaiting cat abundance and PPRI on baiting efficacy (BE). The best model for predicting efficacy of baiting contained only PPRI. This simple model was able to predict baiting success over the entire range of outcomes, from highly successful ( >75% cat reduction) to unsuccessful (0% cat reduction). The ability to predict feral cat BE in advance of planned toxic baiting operations will provide a valuable tool for wildlife managers involved in cat control.

Catastrophic cat predation: A call for predator profiling in wildlife protection programs

“…Roy et al (2002) reported that generic control of mongoose, Herpestes javanicus, failed to prevent uncommon but significant predation events on the rare pink pigeon, Columbus mayeri, in Mauritius and called for studies into the behavioral ecology of the mongoose. Several studies suggest that predation pressure of feral cats may also vary intraspecifically due to their size or prior learning (Childs, 1986;Christensen et al, 2012;Kuo, 1930). Dickman and Newsome (2015) identified specialist predators within several populations of feral cats that achieved maximal hunting success when attacking particular prey.…”

Dying to be clean: pen trials of novel cat and fox control devices

“…Although poison baiting can be successful for con trolling feral cats when they are food-stressed (Burrows et al 2003;Johnston et al 2011), this control method has limited efficacy when prey are abundant (Risbey et al 1997;Algar et al 2007;Moseby et al 2009;Christensen et al 2013). Indeed evidence suggests that an increase in cat predation following successful fox baiting may be implicated in subsequent declines in wildlife vulnerable to cat predation (Christensen and Burrows 1995;Risbey et al 2000;Johnson 2006;Read and Ward 2011).…”

Placing invasive species management in a spatiotemporal context

“…Algar and Burrows (2003) found that cat densities could be reduced by 80-90% from baiting at 100 baits/ km 2 on islands. Christensen et al (2013) repeatedly baited Lorna Glen reserve on the Australian mainland at 50 baits/km 2 , and we use their observations from 2003 and 2004. We solve Eq.…”

“…Here, we consider a situation where the effectiveness of control efforts varies throughout the year. For example, the willingness of feral cats to consume poison baits is inversely related to the seasonal availability of alternative food sources (Algar et al 2007, Christensen et al 2013. Although managers often cope with varying control effectiveness by halting control efforts during periods of low efficacy, this is not necessarily the best response.…”