High post-sex survival of the world's largest semelparous mammal

Males of the endangered northern quoll (Dasyurus hallucatus) are facultatively semelparous, often dying following their first breeding season. This is often driven by high breeding costs: males travel and mate extensively in breeding season, resulting in reduced body condition. Annual post-breeding survival rates for male northern quolls have been recorded between 0% and 12.5% across their range in northern Australia. We highlight an observed 50% survival rate of male northern quolls (3 of 6) living into their second year in a Pilbara mining landscape. High male survival here may be attributed to above average rainfall in the landscape and reduced breeding opportunities, due to low female abundance—likely driven by large amounts of unfavourable mining land. This likely led to lower hormonal stress associated with breeding for males, as well as increased resource availability. Given northern quoll population persistence is highly dependent on breeding success, high survival of male northern quolls may inadvertently stabilize populations if they can breed again in a second year, though this is yet to be observed in the Pilbara region. Nevertheless, semelparity of male northern quolls likely varies with environmental and demographic factors, demonstrating that northern quoll populations may be resilient to disturbance in an unpredictable semi-arid environment.