Factors Affecting Multiple Paternity: Insights From the Eastern Quoll (Dasyurus viverrinus)

Breeding systems influence population dynamics and genetic diversity, especially when a population is small or isolated. To examine population-level drivers of multiple paternity, we combined long-term demographic data and 1745 single-nucleotide polymorphisms from a reintroduced population of eastern quolls (Dasyurus viverrinus). We also conducted a cross-species comparison of multiple paternity occurrences within the Dasyuridae (including the eastern quoll) to look for taxonomic patterns. Pedigree reconstruction revealed high rates of multiple paternity, with 47%-85% of litters sired by more than one male (depending, respectively, on whether all litters or only those with > 1 offspring were assessed). Reconstructed litters contained up to three sires. Trait-based generalised linear mixed modelling showed individual reproductive success was significantly correlated with higher bodyweight, lower age, and having a fawn, rather than black, colour morph. Across the Dasyuridae family, higher rates of multiple paternity were associated with shorter lifespans, but not sexual size dimorphism or greater intersex aggression. Our findings indicate that individual traits predict reproductive success in the eastern quoll, and that within a polyandrous taxonomic family, the likelihood of multiple paternity can depend on the evolutionary life history of the species (e.g., lifespan).