Browsing by Author "Schoener, Ellen Renate"
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- ItemGastrointestinal parasites in endemic, native, and introduced New Zealand passerines with a special focus on coccidia :a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University, Palmerston North, New Zealand(Massey University, 2010) Schoener, Ellen Renate; Schoener, Ellen RenateThere is not much known about the taxonomy, prevalence, epidemiology, and life cycles of gastrointestinal parasites of passerine birds in New Zealand and there is a possibility that many of these parasites might have been introduced by non-native passerines. Approximately half of all New Zealand native passerine species are on the endangered list. Translocations to safe areas are the major management technique used to safeguard them for the future. Under natural conditions, gastrointestinal parasites seldom pose a threat. However, factors such as quarantine for translocation, overcrowding, low genetic diversity, and/or habitat changes may cause an infection outbreak that can severely affect the host species. The effect these parasites might cause under these conditions may therefore endanger translocation and captive breeding programmes. The purpose of this study was to generate baseline data on the gastrointestinal parasites of New Zealand native and introduced passerine birds with an emphasis on the coccidian parasites. Faeces and tissues were examined from 361 birds from six native and four introduced species. Parasites were identified using flotation and microscopy, in the case of the coccidia also PCR analysis and DNA sequencing were used. Of the samples examined, 90 (24.93 %) were positive for coccidian parasites. Sequencing analysis revealed a close relationship between these parasites and other avian coccidia of the genus Eimeria. I found one coccidia species with a unique sequence in North Island robin and one in North Island saddlebacks, at least two different unique sequences in hihi and two in blackbird as well as at least three in tui. In addition, 18 (4.99%) birds were positive for trematodes, 30 (8.31%) for cestodes and three (0.83%) for Capillaria. Most of these parasites were reported during this study for the first time. The results of this study have therefore revealed a whole range of new species of parasite infecting passerines in New Zealand providing a glimpse into the biodiversity of passerine parasites in New Zealand. This knowledge will be useful when taking management decisions particularly for translocations of protected species by alerting managers of possible sources of disease outbreak.
- ItemThe impact of conservation translocations on vector-borne parasites : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Palmerston North, New Zealand(Massey University, 2015) Schoener, Ellen RenateWildlife conservation in New Zealand relies on translocations of endangered species to safe sites. While knowledge of the biology and behaviour of translocated hosts has steadily increased, the role of parasites in wildlife translocations has been largely overlooked. Parasites can affect their host’s survivorship during translocations by causing disease. However, failure to translocate or reintroduce a host specific parasite with its endangered host can contribute to the extinction of the parasite with unforeseen consequences for the future of the host or even the whole ecosystem. The main aims of this study were to establish baseline data on the impact of North Island saddleback translocations on their avian malaria (Plasmodium spp.) parasites as well as gaining further insight into potential vectors in New Zealand. The study was also intended to contribute to the development of recommendations for future parasite screening programmes for native passerine translocations. Saddlebacks and Plasmodium were chosen because of the detailed saddleback translocation history and its known relationship with the parasite. As a result of this study, several Plasmodium lineages previously unrecorded in saddlebacks and New Zealand were identified, for example, the native Kokako01 and one lineage closest related to two lineages from the Americas. Nonetheless, the most frequent lineages found were the cosmopolitan P. elongatum GRW6 and LINN1, and P. vaughani SYAT05, common in birds introduced to New Zealand. This finding suggests that endemic parasites may have already become rare or extinct. In addition, Plasmodium DNA was detected in both native and introduced mosquitoes that may act as vectors. A qPCR assay was developed that was found to be a cost effective and rapid screening tool for the detection of Plasmodium in native birds suffering from acute infection, presenting with clinical symptoms, and in birds that were found dead. . I conclude that future translocations should consider the movement of endemic parasites with their hosts. How this should happen is open for future studies. However, I urge managers to start considering this issue now as New Zealand has already recorded the extinction of one endemic parasite and many more may have already been lost without knowledge.