Behavioural responses of Australian lizards towards visual cues of feral cats

Abstract

Invasive mammalian predators have caused population declines and extinctions of wildlife worldwide. Many of these species exhibit some form of prey naïveté, which heightens their vulnerability to novel predators. In Australia, introduced feral cats (Felis catus) and red foxes (Vulpes vulpes) have had a particularly negative effect on native fauna, with the impacts of cats on mammals and birds well documented. Although feral cats are known to regularly prey on Australian reptiles, little is known about the behavioural responses of reptiles to cats, including whether native reptiles can recognise cats as a predation risk, and if so, which cues they use. Aims. We investigated behavioural responses of two Australian lizard species, the shrubland morethia skink (Morethia obscura) and eastern striped skink (Ctenotus robustus), to the visual cues of feral cats in semiarid, south-eastern Australia. Methods. We used arena trials to test lizards for predator recognition by using visual cues of an alien mammal predator (taxidermied cat, Felis catus), a native mammal predator (taxidermied western quoll, Dasyurus geoffroyi) and a mammal non-predator (taxidermied European rabbit, Oryctolagus cuniculus), as well as a procedural control (bucket) and a negative control (nothing). Key results. We found little evidence of behavioural change when lizards were exposed to the taxidermied cat. Morethia obscura basked less when exposed to all treatments and C. robustus increased vigilance when in the presence of the taxidermied cat, but overall responses were similar among treatments. Conclusions. Our findings suggest that stationary visual cues of cats do not trigger behavioural responses in these two lizard species. Implications. Future research should assess behavioural responses to combinations of cat cues (e.g. movement, scent). Developing a deeper understanding of predator recognition systems and prey naïveté in reptile communities will be crucial for conservation of Australian reptiles that are negatively affected by feral cats.