Predator–prey behavioural interactions between feral cats and two arid Australian geckos

The impact of feral cats on Australian wildlife contributes to species decline across the country. Reptiles play a significant role in feral cat diet, especially in the arid zone where reptile diversity and density are high. In this study, predator–prey interactions between feral cats and two arid-zone gecko species, the common knob-tail gecko, Nephrurus levis , and the beaded gecko, Lucasium damaeum , were investigated. Typically, N. levis responds to threats by bluffing, whereas L. damaeum flees. We hypothesized that these behavioural differences may affect their likelihood of avoiding predation. Using Perspex reptile enclosures in a large outdoor cat pen, the behaviour of gecko and feral cat was observed to assess how cats and geckos responded during and after interactions. Cats visited the Perspex enclosures with N. levis 11 times more than the control enclosures, and they had on average 15 s longer interactions. Reptile behaviour was compared before, during and after cat interactions. N. levis spent significantly more time in a stationary head-down hiding response during and after cat interactions, whereas L. damaeum showed no behavioural change. The longer length of interactions between cats and N. levis indicates that N. levis may be more susceptible to cat predation than L. damaeum despite their recognition of cats as a threat. Reptile body size showed no effect on the number of interactions with cats and interaction length, which indicates that other factors such as prey preference or posture may have been responsible for the increased interest towards N. levis . Bluffing behaviour was not observed possibly because of the enclosure, which prevents cats from approaching closer than 30 cm to geckos. However, in the wild, this behaviour could reduce predation impacts. Further research on reptile responses to feral predators is necessary to understand the interspecific variation in susceptibility of reptiles to cat predation. • Two arid geckos exhibited poor antipredator response to cats. • Gecko size had no influence on cat interactions. • Lucasium damaeum did not change behaviour in response to cats. • Cryptic predatory response for Nephrurus levis did not prevent detection by cats.