Conference Agenda

Temperature has been known to affect the distribution of parasites in their hosts, including the hibernation period. Studies have shown that parasite numbers decline during hibernation, while others are able to survive alongside the host, known as co-hibernation. Hedgehogs (Erinaceus europaeus) hibernation is influenced by temperature, but in New Zealand temperatures vary, affecting the length of time hedgehogs hibernate with hedgehogs in the north possibly not hibernating at all. The aim of this study is to see if parasite load is affected by the length of time in hibernation. We hypothesise that with increased time in hibernation there will be a decrease in the parasite load. Hedgehogs will be caught across New Zealand before hibernation with both endoparasites and ectoparasites species being identified. Tracking devices will be placed on the hedgehogs so they can be recaught and analysed once the hibernation finishes. We expect to find that the Northern end of the North Island where hibernation is either absent or minimal in New Zealand will have a higher abundance and diversity of parasites in hedgehogs. This study hopes to explore how hibernation duration influences the host-parasites dynamics in hedgehogs, potentially contributing to a broader ecological and parasitological knowledge.

The broad aim of my research is to explore the evolutionary trends that exist between a parasite which induces a high rate of mortality in its host, and its group of hosts. The relationship between the genetic variation of the parasite and the variation of the parasite’s microbiome will also be a focus. This will be done by investigating both the geographic distribution of variation in these three groups as well as the cophylogeny between the parasitoids and their hosts.

This study focuses on members of the order Mermithida, a group of parasitic nematodes that infect invertebrates, with mermithids and hosts being collected from around the South Island of New Zealand. The morphological and behavioural effects of mermithid infection on their hosts will also be studied to inform how the cophylogenetic history and geographic distribution of mermithids and their variation may be affecting the current relationship between the parasites and their hosts. This raises an opportunity to investigate whether the phenotypic effects that a parasite has on its hosts varies over a geographic distance and potentially whether it correlates with genetic or microbial variation between parasite populations.

Toxoplasma gondii, an Apicomplexa protozoan parasite, poses significant risk to wildlife and human health with an increasing prevalence in new and endemic areas. Since introduction to New Zealand, toxoplasmosis has been found to cause morbidity and mortality in a range of native New Zealand species, however, T. gondii remains poorly understood in avian species. Toxoplasmosis has been found in cherished native birds such as kiwi (Apteryx spp.), kākā (Nestor meridionalis), and kererū (Hemiphaga novaeseelandiae), necessitating further investigation into the impacts and distribution of T. gondii in New Zealand. In this talk, I will summarize previous global T. gondii research on wild birds to provide a broader perspective on infections in New Zealand. Additionally, I will outline the appropriate next steps to advancing T. gondii research in New Zealand. These include testing currently used detection methods for accuracy and precision, expanding on our current understanding of avian toxoplasmosis prevalence in New Zealand, and conducting a multifaceted inquiry into ecological and anthropogenic factors driving infection dynamics. By addressing these knowledge gaps, we aim to develop effective strategies for mitigating the impacts of T. gondii on avian populations and safeguarding both wildlife and human health in New Zealand and on a global scale.

The Tasmanian wedge-tailed eagle, Aquila audax subsp. fleayi, is an endangered species found only in Tasmanian and some of the surrounding islands. As a major predator, it plays a key role in the ecosystem and by extension, so does its parasites. Previously, only one species of parasite, Microtetrameres paraccipiter, had been reported from this subspecies and only four species had been reported from the mainland species, Strigea glandulosa, Neodiplostomum spathula, Thelazia aquilina and “Eye worms”. A helminthological survey of 137 Tasmanian wedge-tailed eagle carcasses from various locations across Tasmania found nine different species of parasite including Capillaria, Microtetrameres, Strigea, Neodiplostomum, Dispharynx and Brachylaimidae. A detailed morphological and molecular examination of the Microtetrameres sp. and Strigea sp. suggested these could be new species. For the Microtetrameres sp., histopathology and stable isotope analysis was also performed. A comprehensive analysis of parasite ecology for Aquila audax subsp. fleayi is provided, including prevalence and mean intensity of infection.

Birds play a significant role in the spread of diseases as they can migrate great distances in relatively short periods of time. Waterbirds are of particular interest to parasitology as they are exposed to a great diversity of parasites due to using both aquatic and terrestrial environments. Much like the rest of Australia’s native fauna, very little is known of the parasitic fauna of Australia’s native ducks. The current knowledge is outdated with the last significant works being completed close to 50 years ago. Since this publication the way in which parasites are studied has significantly changed with the introduction of improved morphological and molecular techniques.

This study aimed to determine the cause of proventricular lesions observed in native Australian ducks. Postmortem examination revealed the presence of Tetrameres nematodes. While Tetrameres spp. are known to cause pathology in poultry, our findings suggest low burdens may not induce significant mortality in ducks. This study provides important morphological and molecular data, emphasising the importance of accurate pathogen identification and a multidisciplinary approach for disease investigations. Future research on Tetrameres species can enhance disease control and conservation efforts in avian populations.