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    A study of coccidial parasites in the hihi (Notiomystis cincta) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University
    (Massey University, 2001) Twentyman, Caroline Millicent
    A systemic protozoal disease resembling atoxoplasmosis has been found to be a serious problem in the captive hihi population at the National Wildlife Centre (N.W.C.), Mt Bruce, Masterton, causing high juvenile mortality. The literature on the Genus Atoxoplasma is reviewed, with attention focusing on the taxonomy, history, and life cycle of the organism, named and unnamed species, identification, epidemiology and clinical signs of infection. Atoxoplasma-like organisms have been recognized in birds since 1900 but difficulties in identification and in classification have meant that the genus is still inadequately defined and poorly understood. Monitoring of oocyst shedding from captive hihi at the N.W.C. during the 1997-1998 and 1998-1999 breeding seasons confirmed that the most consistent shedding was by the chicks/juveniles which had at least two periods of shedding: one in the nestling stage and one post-fledging. The earliest recorded excretion was at 9 days of age. Post-fledging, there was a period of high oocyst shedding between 6.5-8 weeks of age during both seasons. Some chicks had intermittent periods of excretion of high numbers of oocysts throughout the year although the months of December through to, and including, February were the times when high numbers of oocysts were shed by the chicks most consistently. The adult hihi at the N.W.C. passed oocysts only sporadically, with the exception of one hand-reared bird which had little exposure to conspecifics as a juvenile, and another bird that was in poor health at the time of shedding. Small numbers of coccidial oocysts were also present in faeces collected from hihi on Tiritiri Matangi and Mokoia Islands but, largely because of infrequent sampling, no shedding patterns were discernible. It is proposed that hihi normally develop immunity to this coccidial organism as they mature if they are reared naturally, but might shed oocysts if suffering from concurrent disease. Treatment with toltrazuril (Baycox solution 2.5%, Bayer) eliminated the shedding of oocysts in all birds. However, oocyst numbers sometimes rose again very quickly suggesting that toltrazuril is effective against the intestinal forms of this coccidia but not against the extra-intestinal forms. Difficulties were experienced in the in vitro sporulation of oocysts shed by birds from the N.W.C. although those recovered from the two islands sporulated relatively easily. The reasons for this were not established but it is suggested that the sporulation difficulties may have been due to management factors at the captive institution, such as the use of some medications. Preliminary morphological characteristics of sporulated oocysts of the Isospora-type are described. Two main types of coccidia were identified: Group A which comprised coccidia which had subspherical oocysts, and Group B which had ellipsoidal oocysts. Both types of coccidia were found in birds from all three locations. These preliminary epidemiological studies suggest that infection is maintained in chicks and juveniles with oocysts remaining viable in the environment for extended periods of time. Further work on oocyst shedding by adults during the breeding and oocysts viability in the environment is required in order to confirm this hypothesis. Transmission studies using starlings as recipient birds for both starling and hihi oocysts were not completed because of the unavailability of appropriate infective material at the required time. Another study using a single hihi as the recipient of sporulated hihi oocysts was also not completed because of the death of the hihi due to a fungal infection. A transmission study where sporulated hihi oocysts were inoculated into zebra finches, was completed and there was no evidence of infection, supporting the belief that these coccidia are species-specific. The gross and histological findings on necropsy of 12 cases of coccidial infection in hihi from the N.W.C. are described in detail including the locations of the various coccidial forms within the body. These findings are compared with cases of Atoxoplasma and Atoxoplasma-like infections in birds recorded in the literature. The most outstanding feature of the infection in hihi is the intestinal pathology which involves extreme thickening of the lamina propria with an overwhelming invasion by coccidial forms into the lamina propria and the intestinal epithelial cells. No atoxoplasmosis cases in other avian species exhibit similar intestinal pathology. Although there are some common aspects in the hepatic and splenic pathology, and in the tissue location of the different coccidial life cycle stages, there is currently insufficient consistent similarity to justify placing the hihi coccidia in the Genus Atoxoplasma. The taxonomic classification of this coccidia therefore remains uncertain.
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    The anatomy and histomorphology of the uropygial gland in New Zealand endemic species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Zoology at Massey University, Palmerston North, New Zealand
    (Massey University, 2013) Reynolds, Sian
    Considering that there are more than 10,000 species of birds on earth, and that the uropygial gland is the most prominent integument gland in this vertebrate group, it is puzzling that little is known about its morphology and function. The current hypotheses for the function of the uropygial gland can be placed into four groups: 1) feather maintenance; 2) water-proofing; 3) intraspecific communication/health; and 4) defence against predators and/or parasites. Several studies have examined these hypotheses, although no general function for the uropygial gland has been established. This thesis aimed at reducing the gap in knowledge of the uropygial gland by investigating New Zealand birds. The purpose of this study was to examine the anatomical and histological structure of the uropygial gland in New Zealand birds and to investigate the defence hypothesis as a function of the gland specifically in brown kiwi (Apteryx mantelli). Anatomical and histological analyses of the uropygial glands from brown kiwi, great spotted kiwi (Apteryx haastii), hihi (Notiomystis cincta), New Zealand bellbirds (Anthornis melanura), tui (Prosthemadera novaeseelandiae), and saddleback (Philesturnus carunculatus) were carried out. The anatomy and histology of all glands were compared both within family and order and to those available from other species worldwide. The defence hypothesis function of the uropygial gland was investigated using the tick species Ixodes anatis from the skin of brown kiwi. This study revealed a range of uropygial gland characteristics in the kiwi, hihi, New Zealand bellbird, tui, and saddleback that were not know to previously exist in other species. For example kiwi uropygial glands were found to possess eight primary sinuses. Comparison of the New Zealand passerines revealed that bellbirds possess the largest gland in relation to body size out of the four species. The uropygial secretion of brown kiwi may play a role in parasite repellence as both males and female ticks were deterred from the secretion. Based on histomorphology I suggest that rather than a single function, the gland may have species/group functions. However, this hypothesis still remains enigmatic due to the lack of birds studied to date.
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    Gastrointestinal 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 Renate
    There 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.