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    A retrospective analysis of post-mortem findings in New Zealand weka (Gallirallus australis), 1995-2022
    (Taylor and Francis Group, 2024-11-10) Wichtel N; Vallée E; McInnes K; Hunter S
    AIMS: To determine the major causes of mortality in weka (Gallirallus australis), and to investigate associations between causes of mortality and captivity status, age, sex, decade of submission, and season. METHODS: Necropsy records were obtained from the Massey University School of Veterinary Science/Wildbase Pathology database (Palmerston North, NZ) for weka submitted between 1 January 1995 and 22 March 2022. Causes of mortality were classified into categories based on aetiology. Frequency of diagnosis was tested for association with region of submission, captivity status, age, sex, decade, and season of death. RESULTS: A total of 156 necropsy reports were included in this study, of which 96 (61%) were from wild weka, 57 (36.5%) were captive, and three (1.9%) were of an unspecified captivity status. Weka were submitted from 12 regions across New Zealand. There were 65 (41.7%) adults, 16 (10.3%) juveniles, and 75 (48.1%) weka of an undetermined age among the 156 submissions. Of the weka with a known sex, there was a similar distribution between sexes with 27 (17.3%) males and 29 (18.6%) females. A cause of death was determined in 132/156 (84.6%) cases, with 24/156 (15.4%) cases having an unknown diagnosis. The leading cause of mortality in weka was traumatic injury, which occurred in 65/156 (41.7%), followed by infectious and/or inflammatory diseases in 26/156 (16.7%), and degenerative and/or nutritional conditions affecting 20/156 (12.8%) cases. The distribution of the primary causes of death was found to be dependent on captivity status (p < 0.001). Traumatic and toxic causes of death were more frequent in wild than captive weka. The cause of death was also dependent on season (p < 0.001). There was a significant difference in cause of death between summer and all other seasons (spring p = 0.008; autumn p < 0.001; winter p < 0.001) and between autumn and winter (p = 0.008). CONCLUSION: Trauma was identified as the most significant cause of mortality in the free-living weka necropsied. The inherent and uncertain submissions biases, and low case numbers over a long period of time, means that temporal patterns and the effect of captivity status on causes of mortality should be interpreted with caution.
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    Body mass and hibernation microclimate may predict bat susceptibility to white-nose syndrome
    (John Wiley and Sons, Ltd, 7/01/2021) Haase CG; Fuller NW; Dzal YA; Hranac CR; Hayman DTS; Lausen CL; Silas KA; Olson SH; Plowright RK
    In multihost disease systems, differences in mortality between species may reflect variation in host physiology, morphology, and behavior. In systems where the pathogen can persist in the environment, microclimate conditions, and the adaptation of the host to these conditions, may also impact mortality. White-nose syndrome (WNS) is an emerging disease of hibernating bats caused by an environmentally persistent fungus, Pseudogymnoascus destructans. We assessed the effects of body mass, torpid metabolic rate, evaporative water loss, and hibernaculum temperature and water vapor deficit on predicted overwinter survival of bats infected by P. destructans. We used a hibernation energetics model in an individual-based model framework to predict the probability of survival of nine bat species at eight sampling sites across North America. The model predicts time until fat exhaustion as a function of species-specific host characteristics, hibernaculum microclimate, and fungal growth. We fit a linear model to determine relationships with each variable and predicted survival and semipartial correlation coefficients to determine the major drivers in variation in bat survival. We found host body mass and hibernaculum water vapor deficit explained over half of the variation in survival with WNS across species. As previous work on the interplay between host and pathogen physiology and the environment has focused on species with narrow microclimate preferences, our view on this relationship is limited. Our results highlight some key predictors of interspecific survival among western bat species and provide a framework to assess impacts of WNS as the fungus continues to spread into western North America.
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    Acknowledging the Māori cultural values and beliefs embedded in rongoā Māori healing
    (University of Victoria, 2017) Mark G; Chamberlain KP; Boulton A
    An exploration of rongoā Māori (a system of Māori healing based on Māori cultural traditions) was conducted to ascertain the cultural values and beliefs of Māori, the Indigenous peoples of Aotearoa/New Zealand, that are related to Māori healing. A Kaupapa Māori approach utilising Māori cultural concepts throughout the research process guided the overall study design. Semi-structured narrative interviews were conducted in 2009 and 2010 with 17 rongoā Māori healers. The rourou Māori method of data analysis, a 3-step process created specifically for this project, was employed to analyse healers’ talk about the underlying concepts of rongoā Māori healing. Two key topics emerged: concepts of healing, and the focus of healing. The importance of acknowledging Māori cultural values and beliefs inherent within rongoā Māori healing concepts and the focus of healing is discussed.