Prey naivety in southern hairy-nosed wombats (Lasiorhinus latifrons) isolated from dingoes (Canis familiaris) for over 80 years

Much of the southern hairy-nosed wombat (SHNW; Lasiorhinus latifrons) population has been functionally isolated from its only major predator, the dingo (Canis familiaris), for over 80 years. In the absence of predators, prey species can lose the ability to recognise or respond appropriately to predation risk, which may be detrimental if re-exposed. This study investigated whether SHNWs show different behavioural responses to predator scent cues in dingo-exposed versus dingo-absent areas of their distribution. Camera traps were deployed at SHNW burrows in both locations and assigned one of the following three olfactory treatments: dingo faeces (predator), rabbit faeces (neutral), or no scent (control). An ethogram of SHNW behaviours was established, with behaviours divided into active, inactive, vigilant, investigation, scent investigation and grooming. A beta regression model was applied to analyse the proportion of time spent in various behaviours, while logistic and gamma models assessed the likelihood and duration of scent cue investigation. Our results showed similar response patterns between both study locations, where SHNWs were more likely to investigate dingo scent than rabbit scent. However, dingo-exposed SHNWs were significantly more likely to investigate scent in general, suggesting they may be more attentive to environmental change and potential threat cues than were dingo-absent SHNWs. Although not a direct anti-predator response, investigation of novel scent cues is the essential first stage of threat assessment to determine whether a behavioural response is necessary. This research offers foundational insight into experience-based predator responses in SHNWs, thereby improving our understanding of prey naivety.