Breeding systems can impact population dynamics and genetic diversity, especially when a population is small or isolated. Here, we used a long-term dataset of demographic data combined with 1,745 single nucleotide polymorphisms to investigate mating patterns within a population of the eastern quoll (Dasyurus viverrinus) reintroduced to a conservation-fenced reserve. Pedigree reconstruction revealed that 47.62% of eastern quoll litters exhibited multiple paternity, containing up to three sires. Trait-based generalised linear mixed-modelling showed reproductive success was significantly correlated with bodyweight, age, and colour-morph. A cross-species comparison within the Dasyuridae (which includes the eastern quoll) showed that shorter lifespan increased the rate of multiple paternity, but the degree of sexual size-dimorphism or intersex aggression does not. Our study indicated that individual traits can predict reproductive success, but the likelihood of multiple paternity can depend on the evolutionary/life history of the species (e.g., lifespan). Further research should focus whether the interaction between breeding system and life history may predict patterns of multiple paternity within a species.
