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    Health risks associated with the conservation of kākāpō (Strigops habroptilus) on offshore islands : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Manawatū, New Zealand
    (Massey University, 2021) Meda Gedara, Chamindani Manjula Jayasinghe
    New Zealand has a long history of using translocations of native fauna for conservation and offshore islands have been regarded as isolated ecosystems for conservation purposes. Maintaining the biosecurity of these islands is a fundamental part of conservation management. Island translocation has protected the endemic New Zealand parrot kākāpō (Strigops habroptilus) from becoming extinct and resulted a viable population in three offshore islands outside its historical range. However, kākāpō have been affected with novel diseases arising in the island sanctuaries. The aim of this research was to investigate the health risk for kākāpō in offshore islands, focusing on two main diseases. Exudative cloacitis is a disease of the cloaca in kākāpō from Whenua Hou for which no aetiology has been identified. An epidemiological study was conducted to identify the factors associated with the initiation of this disease in kākāpō. Results suggested that the disease is unlikely to have an infectious origin and diseased birds were not geographically clustered within Whenua Hou but reflected the kākāpō distribution within the island. Analysing the pH, moisture and ammonium content of kakapo roost materials did not show any evidence for the cause of the disease in the cloaca. Disease incidence has not been affected by the annual maximum temperature and rainfall each year. Erysipelas, an acute infection caused by the bacteria, Erysipelothrix rhusiopathiae, emerged as a small cluster of mortality in translocated kākāpō in 2004, and has subsequently been diagnosed as a sporadic cause of death for kākāpō and other endangered New Zealand fauna. This study reported the presence of E. rhusiopathiae in different seabird species in two islands Whenua Hou and Te Hauturu-o-Toi through a targeted survey. Whole genome sequencing revealed that there was a geographic difference in genomic diversity of E. rhusiopathiae, and phylogenetic evidence suggested seabirds as a possible reservoir of the organism for endangered native land birds. An Erysipelothrix spp. phylogenetically different from E. rhusiopathiae was detected in Cook’s petrels (Pterodroma cookii) and in kākāpō indicating the diversity in the genus Erysipelothrix in these island ecosystems. The investigations in this thesis demonstrate that while island translocations have been instrumental in conserving endangered fauna in New Zealand, this conservation strategy does expose the translocated populations to novel health risks. Disease management should be a priority in managing endangered species and these results should help to guide management actions for new health issues as they arise.
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    Faecal steroid measurements for the assessment of reproductive function in Japanese quail (Coturnix coturnix japonica) and kakapo (Strigops habroptilus) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology at Massey University
    (Massey University, 2002) Hawke, Emma Jane
    The kakapo (Strigops habroptilus) is an endangered parrot endemic to New Zealand and little is known of its reproductive physiology. Reproductive function is conventionally determined by the measurement of reproductive steroids in plasma samples. This is impractical and invasive in endangered, free-living species. However, the measurement of reproductive steroids in avian faecal samples is practiced. Few studies have documented strong relationships between faecal and plasma steroid concentrations. The objectives of this study were to develop and validate a faecal extraction method for the measurement of oestradiol, progesterone and testosterone in Japanese quail (Coturnix coturnix japonica); determine the relationships between steroid concentrations and gonadal development in quail; and define annual faecal hormone cycles of kakapo in relation to their breeding status. Groups of male and female quail were held on different photoperiodic and temperature regimes to produce birds with a range of gonad sizes and steroid concentrations. Steroid concentrations were measured in faeces and plasma by radioimmunoassay. Positive relationships were demonstrated between plasma and faecal steroid concentrations. Faecal steroid concentrations had strong positive relationships with ovary and testis size in female and male quail respectively. The extraction method developed was then applied to faecal samples, which were collected from kakapo in their free-living environment on Whenua Hou (Codfish Island). The samples were collected from identified birds over three potential breeding seasons. There were annual cycles of hormone concentrations that corresponded with cycles of breeding activity in females and males. No significant differences were found between breeding and non-breeding years for faecal concentrations of all three hormones, suggesting that kakapo undergo a degree of gonadal development each year. Annual hormone profiles for individual birds supported this finding. This study quantifies the value of collecting multiple faecal samples in both captive and wild situations and demonstrates the power and value of faecal steroid analysis.
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    The Kakapo (Strigops habrotilus, Gray, 1847) its food, feeding and habitat in Fiordland and Maud Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University
    (Massey University, 1977) Gray, Richard Scott
    An extensive Wild Life Service conservation program to save the Kakapo parrot from extinction has permitted the collection of feeding data in Fiordland and on the sancturary, Maud Island in Pelorus Sound, between November 1974 and March 1977. Four expeditions, each of 4 to 6 weeks between January 1975 and March 1977 enabled my spending over 4 months in the Fiordland Kakapo areas and a further 6 weeks was spent in the Kakapo search on Stewart Island in July and August 1977. A total of 15 occupied Kakapo territories in Fiordland were found over the two and a half year period. Kakapo from 3 of these territories were moved to Maud Island and monthly visits between September 1975 and August 1976 enabled regular collection of droppings for faecal analysis study. A combined appraisal of feeding sign and faecal content, using cuticle analysis techniques has enabled a more accurate understanding of the Kakapo's diet and its seasonal variations to be determined. The mobility of the Kakapo could also be roughly estimated and on Maud Island it appeared the Kakapo were learning to obtain new foods. Investigation of faecal material has confirmed early reports that Kakapo are herbivorous. No insect or animal parts were found in fresh droppings. The variety of plants fed upon was extensive. In Fiordland 79+ species of herbs, grasses, shrubs and trees have been identified and on Maud Island 28+ species. Roots, rhizomes, twigs, leaves, buds, flowers, flower-stems, fruits and seeds are utilized. Feeding areas in Fiordland have all been found in the vicinity of the male Kakapo's track and bowl systems. These are generally located about tree line at approximately 1050 meters. The tree line in many areas is lower than expected, however, due to terrain and avalanche damage. Kakapo feeding areas, associated with track and bowl systems extend from 550 meters to 1200 meters above sea level. On Maud Island feeding sign and droppings found were concentrated on or close to recently excavated roads, although it was apparent the birds were covering an extensive area from the coast to the summit (350m). The Kakapo bill is adapted to crushing and extracting nutrients and enables a large proportion of fibre to be retained in the bill. The fibre is frequently squashed into a kidney shaped pellet which is expelled from the mouth. A preliminary investigation into nutrient values of Kakapo food plants is presented and it is suspected the birds select the most nutritious plant species and plant parts as food. On Maud Island the vegetation available as food for Kakapo in preliminary analyses appears to be of greater nutritional value than in Fiordland.
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    The ecology and anatomy of scent in the critically endangered kakapo (Strigops habroptilus) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Zoology at Massey University, Auckland, New Zealand
    (Massey University, 2012) Gsell, Anna Clarissa
    The focus of the research presented here is the analysis of feather scent emitted by a parrot, the kakapo (Strigops habroptilus) and the kakapo’s ability to perceive scent by studying the anatomy of its brain and the olfactory bulb. In addition, behavioural research was conducted to determine the capability of the kakapo’s closest relatives, the kea (Nestor notabilis) and kaka (N. meridionalis) to detect scents and to distinguish between different concentrations of scents.The strong odour of the kakapo is one of the many unique characteristics of this critically endan-gered parrot, but its sense of smell has never been described in detail. The kakapo is the largest par-rot worldwide, it is nocturnal and flightless. Kakapo are herbivorous and it is the only parrot with a lek breeding system. Males defend several display arenas during the breeding season and continuously produce low frequency booming calls. Females come from afar and appraise different males and choose one with which they want to mate. As in all lek mating systems some males make major contributions to the gene-pool of the next generation while others make little or no contribution. Currently it is not known what the female’s choice is based on and why some male kakapo are ‘favoured’ over others. However, it has been observed that favoured males appear to emit a stronger odour than less attractive ones (pers. comm. Kakapo Recovery Team). This study is the first to compare the chemical composition of the kakapo’s scent in relation to season, age and sex. It is also the first study to uncover the kakapo’s ability to smell by conducting a comparative examination of the anatomy and histology of the brain and the olfactory bulb. In spite of its endangered status, the kakapo is a good model in which to study olfaction, as the birds are closely monitored by the Department of Conservation, New Zealand. The birds undergo regular health checks and transmitter changes, allowing access to a large proportion of the population at once and for which their individual history is known. The study of olfaction in kakapo is important as it can contribute to the growing field of avian olfaction, and by elucidating the kakapo’s potential for olfaction conservation managers will be able to make better decisions in their attempt to save this species. The research approach adopted in this dissertation includes the analysis of feather samples from individuals of different sex and age as well as from different seasons using gas chromatography-mass spectrometry. The opportunity to examine the brain as well as the eyes of a kakapo that died at Auckland Zoo, Auckland, New Zealand, allowed a comparative study of the brain, the olfactory bulb and the visual centres (of both the thalomofulgal and the tectogucal pathways) with other Australasian parrots. Additionally, behavioural experiments with kea and kaka, the closest relativesof the kakapo, give insight into two of New Zealand endemic parrot’s and their ability to distinguish between different scents and scents of different concentrations. The findings from this research provide evidence that kakapo distinguish themselves by having one of the largest olfactory bulbs measured in parrots and the highest number of mitral cells, responsible for the transmission of an olfactory neural signal into a behavioural response, counted in any species to date. They also have a strong odour, whose chemical composition shows sexual, age-dependent and seasonal distinction. Furthermore, the study found that kea and kaka are both able to distinguish between different scents and different concentrations of scents.The main conclusions drawn from this study are that kakapo appear to be equipped with a functional olfactory bulb, able to sense olfactory information, but also communicate information that is likely to be of social importance using their plumage scent. In conclusion, this dissertation provides the foundation for future research, in particular to examine the role of the scent in the social life in kakapo, and it provides fundamental insight into the olfactory and visual sensory abilities of the New Zealand endemic kakapo.
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    Characteristics of green rimu fruit that might trigger breeding in kakapo : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Zoology at Massey University, Turitea Campus, Palmerston North, New Zealand
    (Massey University, 2010) Cottam, Yvette
    Species living in unpredictable habitats cannot prepare for a regular reproductive year, and must reproduce when conditions are favourable. The timing of reproduction of the seed predators involves anticipating an abundant food supply by tracking cues or triggers which initiate reproduction. These cues are poorly understood. The most supported theory is that a cue or cues is the size or abundance of the developing fruit crop, and possibly involves nutritional compounds in the crop. The rimu (Dacrydium cupressinum) is a masting podocarp tree strongly linked to reproduction in kakapo (Strigops habroptilus). On Codfish Island kakapo only breed in rimu mast years and nesting is timed so chicks hatch when the rimu fruit crop (the sole food source for chicks) is due to ripen. This thesis investigates the theory that some component in unripe rimu fruit is involved in timing of nesting in kakapo. I characterised seasonal changes (over one year) in nutritional components (gross nutrients), polyphenolic compounds and other potential target polyphenolic substances with possible hormonal activity, including isoflavones and antioxidants, during rimu fruit development.A number of the compounds found in rimu fruit are known to affect reproduction in other species and could be potential triggers for reproduction in kakapo. In non-mast years insufficient fruit is available to trigger reproduction and there is no breeding, supporting the idea that the abundance of the fruit crop is also involved in the timing of reproduction. The trigger for breeding in these birds could be ingestion of a threshold level of a trigger substance or substances, or, as in the antbird, it could be entirely visual. The most likely contenders for the trigger in green rimu fruit include increasing levels of crude protein, crude fat, individual fatty acids, dietary fibre (changing the digestibility of other nutrients), calcium, phosphorus, calcium, total polyphenolic content and antioxidant levels, some flavenoids or a combination of these. It is possible that the physiological changes necessary for reproduction are triggered by the abundance of the unripe fruit crop but that nesting itself is triggered by changes in the green, undeveloped fruit associated with ripening.