Dancing with the devil: Could native predators inside ‘predator‐free’ havens be good for the conservation of threatened native prey species?

As invasive predators continue to drive global biodiversity loss, predator‐free havens are rapidly being established to recover threatened fauna. An unintended consequence of these efforts is that havened populations can lose anti‐predator traits, making them poorly suited for reintroduction into landscapes that contain predators. One approach showing promise in preventing the loss of these critical responses from havened populations is in situ predator exposure. Here we evaluate this via experimental translocations to determine whether predation pressure from a native mesopredator (chuditch; Dasyurus geoffroii ) is effective in retaining behavioural and morphological anti‐predator traits in the Endangered woylie ( Bettongia penicillata ogilbyi ). We conducted replicated reintroductions of semi‐havened (free from invasive predators but exposed to chuditch) and non‐havened (control) woylies into vacant bushland containing chuditch, feral foxes ( Vulpes vulpes ) and feral cats ( Felis catus ). We monitored woylie survival, reproduction, physiology (faecal glucocorticoid metabolites, fGCM), and proxies for behavioural and morphological anti‐predator traits before and for 10 months after their release. We found no effects of source population on weight, pes length, agitation behaviour or fGCM. Survival probability was higher for males, and individuals with higher fGCM levels, but we could not attribute differences in woylie survival to whether they originated from a haven. These findings suggest that sustained predation pressure from chuditch inside the haven has been effective in maintaining anti‐predator responses and supporting the survival of woylies faced with novel invasive predators. Synthesis and Applications . In situ predator exposure can be a valuable tool for preserving anti‐predator traits in havened populations. However, it will be crucial to understand thresholds of predation pressure across contexts that havened fauna can withstand before recommending broad‐scale adoption of this strategy.