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Subject: search.filters.subject.Porphyrio hochstetteri

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    De-novo assembly of four rail (Aves: Rallidae) genomes: A resource for comparative genomics.
    (John Wiley and Sons Ltd, 2024-07-18) Gaspar J; Trewick SA; Gibb GC
    Rails are a phenotypically diverse family of birds that includes 130 species and displays a wide distribution around the world. Here we present annotated genome assemblies for four rails from Aotearoa New Zealand: two native volant species, pūkeko Porphyrio melanotus and mioweka Gallirallus philippensis, and two endemic flightless species takahē Porphyrio hochstetteri and weka Gallirallus australis. Using the sequence read data, heterozygosity was found to be lowest in the endemic flightless species and this probably reflects their relatively small populations. The quality checks and comparison with other rallid genomes showed that the new assemblies were of good quality. This study significantly increases the number of available rallid genomes and will enable future genomic studies on the evolution of this family.
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    Ecology, epidemiology and evolution of enteric microbes in fragmented populations of the endangered takahe (Porphyrio hochstetteri) : 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, 2015) Grange, Zoe Lorraine
    Pathogenic diseases are increasingly recognised as a challenge to the conservation of wildlife. Complex host-pathogen relationships and transmission dynamics in wild populations can limit our understanding of how pathogens contribute to the decline and endangerment of wildlife. Endangered wildlife populations maintained in reserves present a unique opportunity to investigate wildlife host-microbe relationships in a controlled semi-natural environment where diversity, abundance and the movement of species are restricted. The aim of this study was to investigate the prevalence and molecular differentiation of enteric bacteria carried by endangered takahe (Porphyrio hochstetteri). Through the use of network analysis and molecular epidemiology, the study explored the effects of geographic isolation and translocation on the prevalence, transmission and evolution of Campylobacter and Salmonella spp. within fragmented populations of takahe. Translocation and conservation management has created a dynamic network of takahe populations which vary in their likelihood to maintain and transmit pathogens. My study suggests that range expansion following a significant bottleneck and intensive conservation management of takahe has had unforeseen consequences on microbial diversity. The management of takahe in different environmental settings has influenced the carriage of Campylobacter jejuni and Campylobacter coli. A newly discovered rail-associated Campylobacter sp. nova 1 was prevalent in all populations. However, more discriminatory whole genome analysis of isolates detected a significant biogeographic variation in C. sp. nova 1 genotypes. Possible explanations for the observed pattern include the spatial expansion and isolation of hosts resulting in reduced gene flow of Campylobacter spp. and allopatric speciation, and the presence of heterogeneous environmental attributes or cross-species transmission of Campylobacter spp. from sympatric reservoir hosts. An assessment of vertebrate reservoirs in an island ecosystem indicated cross-species transmission of Campylobacter spp. was not likely to be a factor contributing to the maintenance and phylogeographical distribution of Campylobacter spp. in takahe. This study was the first of its kind to explore microbial dynamics in a large proportion of a well-described but fragmented population of a wild bird. Results suggest historic and current management practices may be having unforeseen influences on enteric microbes, the consequences of which are unknown but could be detrimental to the health of translocated populations of takahe.
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    Investigating the physiological impacts of capture and handling on threatened avian species by using surrogate species as models : a thesis presented in partial fulfilment of the requirements for the degree Masters of Science in Conservation Biology at Massey University, Palmerston North, New Zealand
    (Massey University, 2013) Burns, Thomas Stephen
    The conservation management of many threatened species requires the capture and handling of wild individuals for monitoring, translocation or research purposes. However whenever wild animals are captured and handled there is the potential for these procedures to negatively impact the animal and result in altered behaviour or physiology, injury and even death. Therefore this thesis aimed to investigate what physiological impacts routine capture and handling may be having on threatened avian species in New Zealand by using surrogate species of birds as models for threatened birds. Layer hens (Gallus domesticus) were used as surrogates to model the physiological impacts of capture and handling on kiwi (Apteryx spp.). A treatment and control group of hens were serially blood sampled over 72 hours. Hens in the control group were placed in a box between blood samples and hens in the treatment group went through a simulation of a kiwi chase, capture and handling scenario. After 72 hours all birds were euthanized and their muscles examined histopathologically. Wild pukeko (Porphyrio porphyrio melanotus) captured using a net-gun at the Awapuni Sustainable Development Centre in Palmerston North were used as surrogates to model the physiological impacts of capture and handling on takahe (Porphyrio hochstetteri). Wild mallard ducks (Anas platyrhynchos) captured using a net-gun at Massey University’s Turitea campus were used as surrogates to model the physiological impacts of capture and handling on threatened waterfowl such as pateke/brown teal (Anas chlorotis), or whio/blue duck (Hymenolaimus malachorhynchos). All mallards and pukeko captured were serially blood sampled at capture (0 minutes), 30 and 120 minutes. Within each species there was a control group that was held in a box between samples and a treatment group which was handled according best practice protocol for takahe (for pukeko) or pateke (for mallards). A further group of pukeko was also shot using a rifle as comparison. To assess the physiological impact of capture, biochemical analytes measured included plasma concentrations of the enzymes creatine kinase (CK), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH) and the stress hormone corticosterone (CORT). In mallards and pukeko capture using the net-gun the plasma concentrations of uric acid (UA) were also measured. Capture was found to elicit a stress response in all three of the species studied as shown by elevated plasma CORT; however there were differences between species on the effect of capture on plasma CK, AST, GLDH and UA. The handling protocol was found to have minimal impact on the physiological response of any of the species and the impact of capture either overrode the effects of handling or handling protocol was simply not a significant factor on any of the biochemical analytes measured. Layer hens were found to have altered physiology at the commencement of the study, probably due to the high metabolic demands of egg production. There was also significant variation in their ‘normal’ physiology and physiological response between the two weeks they were studied. Layer hens are therefore considered to be inappropriate surrogates for kiwi or any wild bird. Baseline levels of the biochemical analytes of pukeko that were captured using a net-gun and those that were shot were similar. The time of day the pukeko were captured caused significant variation in the concentration of plasma GLDH and UA. Capture did cause significant elevations in plasma CK and AST showing subclinical muscle damage was occurring in the pukeko and this damage and the stress response was greater when the pukeko were captured in flight. Capture also had a significant if less clearly defined impact on renal and gastro-intestinal physiology. Seasonal variation and some time of day variation were observed in the concentration of CK in mallard ducks. While capture caused a significant stress response in captured mallards it did not have a significant effect on CK, GLDH or UA. Plasma AST concentrations decreased significantly following capture albeit by a very small amount. The difference found between species in their physiological response to similar procedures highlights that surrogate species may not be appropriate and validation between the surrogate and threatened species is required. Small differences in the capture technique may have a significant impact on the animal’s physiological response. In conclusion the handling protocol has a minimal physiological impact on these birds following capture and further research should focus on capture techniques and protocols. If surrogate species are used for further research then there should be some attempt to validate that the physiological response observed is similar in the threatened species.
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    Lead exposure in free-ranging kea (Nestor notabilis), takahe (Porphyrio hochstetteri) and Australasian harriers (Circus approximans) in New Zealand : a thesis presented in partial fulfillment of the requirements for the degree of Masters of Veterinary Science in Wildlife Health at Massey University, Palmerston North, New Zealand
    (Massey University, 2009) Youl, Jennifer Marie
    Lead is a highly toxic metal that has been used by humans for over 2000 years. Over this time it has become increasingly apparent that despite its usefulness, lead is one of the most highly toxic substances known to man. Current research into lead exposure of humans focuses on low-level chronic exposure and its effects on learning and behaviour. However, investigations into lead exposure of wildlife are still focussed on mortalities, particularly of waterfowl and raptors, with little known about low-level exposures or the effects on other species. This study examines the exposure of free-ranging kea (Nestor notabilis) from the Aoraki/ Mt Cook village and national park, takahe (Porphyrio hochstetteri) from Tiritiri Matangi, Kapiti and Mana Islands, and the lead associated syndrome of clenched-claw paralysis and leg paresis in harriers (Circus approximans) in New Zealand. Thirty-eight kea had detectable blood lead with concentrations ranging from 0.028 mg/L to 3.43 mg/L (mean = 0.428 mg/L ± 0.581). Analysis of tissue samples found that seven of 15 birds died with elevated tissue lead. Lead exposure may be an important contributing factor in kea mortality. As a result of these findings, lead abatement in areas frequented by kea is being considered. Eighteen of 45 takahe had detectable blood lead concentrations ranging from 0.015 mg/L to 0.148 mg/L (mean = 0.028 mg/L ± 0.042). Analysis of tissue samples from offshore island and Murchison Mountains birds found that all had detectable lead. Despite levels of lead exposure in the population being low and unlikely to result in overt clinical signs, it is widespread and there may be significant exposure of birds living around old buildings. An investigation into the clinical signs, pathology and response to treatment of clenched-claw paralysis and leg paresis in wild harriers was carried out. Harriers with clenched feet had significantly higher blood lead concentrations than those without. In conclusion, lead is a major factor in the expression of this clinical syndrome but other factors not yet identified are playing a role. This study demonstrates that lead is widespread in the New Zealand environment exposing a diverse range of avifauna, and has made some progress towards exploring some of its effects on health and survival.