Browsing by Author "Gartrell B"

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    Influence of management practice on the microbiota of a critically endangered species: a longitudinal study of kākāpō chick faeces and associated nest litter
    (BioMed Central, Ltd., 2022-09-30) West AG; Digby A; Lear G; Armstrong D; Armstrong-James D; Bromley M; Buckley E; Chatterton J; Cox MP; Cramer RA; Crane J; Dearden PK; Eason D; Fisher MC; Gago S; Gartrell B; Gemmell NJ; Glare TR; Guhlin J; Howard J; Lacap-Bugler D; Le Lec M; Lin XX; Lofgren L; Mackay J; Meis J; Morelli KA; Perrott J; Petterson M; Quinones-Mateu M; Rhodes J; Roberts J; Stajich J; Taylor MW; Tebbutt SJ; Truter-Meyer A; Uddstrom L; Urban L; van Rhijn N; Vercoe D; Vesely E; Weir BS; Winter DJ; Yeung J
    Background: The critically endangered kākāpō is a flightless, nocturnal parrot endemic to Aotearoa New Zealand. Recent efforts to describe the gastrointestinal microbial community of this threatened herbivore revealed a low-diversity microbiota that is often dominated by Escherichia-Shigella bacteria. Given the importance of associated microbial communities to animal health, and increasing appreciation of their potential relevance to threatened species conservation, we sought to better understand the development of this unusual gut microbiota profile. To this end, we conducted a longitudinal analysis of faecal material collected from kākāpō chicks during the 2019 breeding season, in addition to associated nest litter material. Results: Using an experimental approach rarely seen in studies of threatened species microbiota, we evaluated the impact of a regular conservation practice on the developing kākāpō microbiota, namely the removal of faecal material from nests. Artificially removing chick faeces from nests had negligible impact on bacterial community diversity for either chicks or nests (p > 0.05). However, the gut microbiota did change significantly over time as chick age increased (p < 0.01), with an increasing relative abundance of Escherichia-Shigella coli over the study period and similar observations for the associated nest litter microbiota (p < 0.01). Supplementary feeding substantially altered gut bacterial diversity of kākāpō chicks (p < 0.01), characterised by a significant increase in Lactobacillus bacteria. Conclusions: Overall, chick age and hand rearing conditions had the most marked impact on faecal bacterial communities. Similarly, the surrounding nest litter microbiota changed significantly over time since a kākāpō chick was first placed in the nest, though we found no evidence that removal of faecal material influenced the bacterial communities of either litter or faecal samples. Taken together, these observations will inform ongoing conservation and management of this most enigmatic of bird species.
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    The effects of annual cycle, source population, and body condition on leukocyte profile and immune challenge in a basal reptile, the tuatara (Sphenodon punctatus).
    (John Wiley and Sons, Inc., 2023-12-03) Lamar SK; Frank HK; La Flamme A; Gartrell B; Ormsby D; Nelson N
    Leukocyte profiles are broadly used to assess the health status of many species. Reference intervals, and an understanding of the factors that may influence these intervals, are necessary for adequate interpretation of leukograms. Using a data set that spans over three decades, we investigated variation in leukocyte profile in several populations of the evolutionarily unique reptile, the tuatara (Sphenodon punctatus). To do this, we first established reference intervals for each leukocyte type according to best practices. Next, we determined that source population and sampling date were the two most important predictors of leukocyte makeup. We found significant differences in the ratio of heterophils: lymphocytes (H:L) between populations, with tuatara on the more resource-stressed sampling island having a significantly higher ratio of H:L. Finally, we found that sampling location, sex, and life stage did not explain variation in the responses of tuatara to stimulation with Concanavalin A and lipopolysaccharide in both 3-(4,5-dimethylthiazol-2-yl)-2,5-di-phenyltetrazolium bromide and Griess assay experiments. Our results offer important insight into the function of leukocytes in reptiles.