Effects of season, age, and sex on infection with endoparasites of brushtail possums,Trichosurus vulpecula, from a forest/farmland site, lower North Island, New Zealand

To assess fully the potential of parasites for the biological control of Australian brushtail possums (Trichosurus vulpecula) in New Zealand, factors affecting the prevalence and intensity of such infections need to be determined. In this study we investigated the effects of season, sex, and age on endoparasite infection in possums from a single forest/farmland site in the lower North Island, New Zealand. Seasonal changes in prevalence and intensity of infection were found for most of the parasites, but the patterns of change varied between species. Parasite prevalences were generally similar in male and female possums, except for the Trichostrongy‐lus spp., which were more prevalent in males. The prevalences of Parastrongyloides trichosuri, Paraustrostrongylus trichosuri and Trichostrongy‐lus retortaeformis were generally lower in young animals (0–1 year) and in animals aged 4 years and older. A body condition index and prevalence of infection showed a significant negative relationship for cocci...