Loss of a grooming enrichment impacts physical, behavioural, and physiological measures of welfare in grazing beef cattle

Pasture-based beef cattle are raised in a range of production environments. Some paddocks may contain trees and other objects that allow for grooming, hence being naturally enriching, whilst others may be barren without these opportunities. Additionally, it is not uncommon for cattle to move between these enriched and barren environments as part of routine management. While the benefits of enrichment are well studied, how this 'enrichment loss' impacts cattle welfare as access to stimuli is removed is unknown. This trial assessed the impacts of the loss of an enriching object (grooming brush) on grazing beef cattle welfare and production characteristics. When grooming brush access was blocked, cattle became dirtier, showed reduced average daily gain, and had elevated faecal cortisol metabolites, although this varied according to the degree of initial individual brush use. Additionally, allogrooming and grooming on other objects were reduced when access to the brush was returned, potentially indicating a rebound effect. These results demonstrate that the loss of adequate grooming objects can impair the overall welfare of grazing cattle; however, further work is needed to determine exactly which natural or artificial objects provide adequate grooming opportunities.

Correction: A 29-year retrospective analysis of koala rescues in New South Wales, Australia

[This corrects the article DOI: 10.1371/journal.pone.0239182.].

How can physiology best contribute to wildlife conservation in a warming world?

Global warming is now predicted to exceed 1.5°C by 2033 and 2°C by the end of the 21st century. This level of warming and the associated environmental variability are already increasing pressure on natural and human systems. Here we emphasize the role of physiology in the light of the latest assessment of climate warming by the Intergovernmental Panel on Climate Change. We describe how physiology can contribute to contemporary conservation programmes. We focus on thermal responses of animals, but we acknowledge that the impacts of climate change are much broader phylogenetically and environmentally. A physiological contribution would encompass environmental monitoring, coupled with measuring individual sensitivities to temperature change and upscaling these to ecosystem level. The latest version of the widely accepted Conservation Standards designed by the Conservation Measures Partnership includes several explicit climate change considerations. We argue that physiology has a unique role to play in addressing these considerations. Moreover, physiology can be incorporated by institutions and organizations that range from international bodies to national governments and to local communities, and in doing so, it brings a mechanistic approach to conservation and the management of biological resources.

Heat stress in horses: a literature review

Healthy adult horses can balance accumulation and dissipation of body heat to maintain their body temperature between 37.5 and 38.5 °C, when they are in their thermoneutral zone (5 to 25 °C). However, under some circumstances, such as following strenuous exercise under hot, or hot and humid conditions, the accumulation of body heat exceeds dissipation and horses can suffer from heat stress. Prolonged or severe heat stress can lead to anhidrosis, heat stroke, or brain damage in the horse. To ameliorate the negative effects of high heat load in the body, early detection of heat stress and immediate human intervention is required to reduce the horse's elevated body temperature in a timely manner. Body temperature measurement and deviations from the normal range are used to detect heat stress. Rectal temperature is the most commonly used method to monitor body temperature in horses, but other body temperature monitoring technologies, percutaneous thermal sensing microchips or infrared thermometry, are currently being studied for routine monitoring of the body temperature of horses as a more practical alternative. When heat stress is detected, horses can be cooled down by cool water application, air movement over the horse (e.g., fans), or a combination of these. The early detection of heat stress and the use of the most effective cooling methods is important to improve the welfare of heat stressed horses.

Human-wildlife interaction: past, present, and future

Human-wildlife interaction is a broad and complex topic. Due to rapid world population growth, there have been greater human impacts on wildlife through agriculture and land fragmentation. In many countries, significant challenges exist with managing wildlife and its negative impacts on humans and wildlife. This special issue discusses human-wildlife co-existence.

Resident wild koalas show resilience to large-scale translocation of bushfire-rescued koalas

Wildlife translocation is increasingly utilized as a conservation management action, to mitigate the immediate negative effects of habitat loss and fragmentation (e.g. from land clearing or bushfires). Previous research has shown that stress responses can help or hinder survival in translocated wildlife and determine the efficacy of translocation as a conservation action. Yet these translocated animals are only one side of the equation, with translocation also potentially impacting the animals in the recipient population. We measured physiological markers of stress (faecal cortisol metabolite concentrations and neutrophil-lymphocyte ratios) and assessed health condition in a wild koala population one year after a major translocation of bushfire-rescued koalas on Kangaroo Island. We expected to find a high population density at the site (>0.75 koalas per hectare) and that resident koalas would show signs of chronic stress and ill health as a result of territorial conflict over food trees and reproductive opportunities. In contrast, we found that only one-fifth of the population remaining at the site were translocated koalas. The overall population density was also much lower (0.21 koalas per hectare) than anticipated. With no evidence of mass mortality at the site, we suggest that the majority of translocated koalas dispersed away from the site. Our stress marker measurements did not differ between the wild koalas and a sample of captive (non-display) koalas at the nearby Kangaroo Island Wildlife Park and were generally low compared to other studies. Veterinary examinations found that most koalas were in good body condition with very few diagnostic indicators of systemic ill health. Overall, our results suggest that, if there is adequate landscape-scale habitat connectivity and opportunity for dispersal, translocated koalas are likely to disperse from the site of release, with limited impacts on recipient koala populations at translocation release sites.

Intra- and Inter-sample Variation in Wool Cortisol Concentrations of Australian Merino Lambs Between Twice or Single Shorn Ewes

Stress in Merino sheep can cause a reduction in the quantity and quality of fine wool production. Furthermore, it has been found that environmental stress during pregnancy can negatively affect the wool follicles of the developing fetus. This study was part of a larger field investigation on the effects maternal shearing frequency on sheep reproductive and productivity outcomes. For this study, we investigated the intra- and inter- sample variation in wool cortisol levels of weaner lambs. We conducted two experiments, the first was to determine the intra- and inter- sample variation in wool samples taken from the topknot of weaned lambs, and the other aim was to determine any difference between maternal shearing treatment (single or twice shearing) on absolute wool cortisol levels of weaned lambs. In the first experiment, topknot wool was collected from 10 lambs, and each sample was further divided into four subsamples, leading to a total of 40 wool subsamples. For the second experiment, we collected the topknot from the 23 lambs produced by the shearing frequency treatment ewes (once or twice shorn). The samples were then extracted and analyzed using a commercially available cortisol enzyme-immunoassay in order to determine the concentration of cortisol in each of the samples. Statistical analysis for the first experiment showed that there was no significant difference between the subsamples of each topknot wool sample taken from each lamb (p = 0.39), but there was a statistical difference between samples (p < 0.001), which was to be expected. In the second experiment, there was a significant difference between the lambs born to the one shearing and two shearing treatments (p = 0.033), with the lambs of the twice sheared ewes having higher average wool cortisol levels [2.304 ± 0.497 ng/g (SE); n = 14] than the ones born to once shorn ewes [1.188 ± 0.114 ng/g (SE), n = 8]. This study confirms that the topknot wool sampling can be a reliable method adapted by researchers for wool hormonal studies in lambs. Second, ewes shorn mid-pregnancy gave birth to lambs with higher cortisol concentrations than ewes that remained unshorn during pregnancy. This result warrants further investigation in a controlled study to determine if maternal access to nutrition (feed and water) may impact on the HPA-axis of lambs.

Interplay Between Stress and Reproduction: Novel Epigenetic Markers in Response to Shearing Patterns in Australian Merino Sheep (Ovis aries)

In this study, we determined the effect(s) of early shearing on Australian Merino ewes (Ovis aries) and their lambs. To test this research question, we used a suite of field and laboratory methods including GPS collars, wool cortisol, and epigenetic change between ewes and lambs identified using Illumina NovaSeq RRBS. Once shorn ewes (n = 24) were kept on their full fleece throughout the entire gestation period, whereas twice (early) shorn ewes (n = 24) had their wool shorn pre-joining. Top-knot wool sample was taken from ewes during pre-joining, day 50 (mid-gestation), and day 90 (late gestation) for laboratory analysis. Ewes were pregnancy scanned at mid-gestation to determine whether they were early or late parturition (this confirmation is provided by the pregnancy scanner based on fetus size). Top-knot wool sample was also taken from the lambs at weaning for hormone and wool quality testing. Ear tissue was taken from ewes at day 50 (mid-gestation) and from lambs at lamb marking for DNA analysis. Results showed that twice or early shorn ewes grazed 10% higher and maintained stronger body condition than once shorn ewes. Wool cortisol levels were also significantly lower in the early shorn ewes between mid- and late gestation. Lambs bred from twice shorn ewes had on average better visual wool quality parameters in terms of micron, spin finesses, and curvature. For the DNA methylation results, when comparing a group of once sheared with twice sheared ewes, we have discovered one locus (Chr20:50404014) that was significantly differentially methylated [False Discovery Rate (FDR) = 0.005]. This locus is upstream of a protein-coding gene (ENSOARG00000002778.1), which shows similarities to the forkhead box C1 (FOXC1) mRNA using BLAST searches. To further our understanding of the potential interaction between pregnancy status and shearing frequency of the ewes, we performed further differential methylation analysis using a combination of shearing treatment and pregnancy scanning status. The comparisons (1) late pregnancy vs. early pregnancy for ewes with one shearing treatment and (2) late pregnancy vs. early pregnancy for sheep with two shearing treatments were carried out to identify associations between loci and pregnancy duration for sheep with either one or two shearing events. We discovered that 36 gene loci were significantly modulated either between different shearing treatments or late vs. early pregnancy status of ewes. This result suggests that maternal pregnancy and nutritional status during gestation influence DNA methylation. We further investigated DNA methylation in lambs and identified 16 annotated gene loci that showed epigenetic modulation as a result of being born from an early or late stage pregnancy. From the genomics data, we pointed out that ewes go through epigenetic modifications during gestation, and there is a degree of intra-individual variation in the reproductive performance of ewes, which could be due to combination of intrinsic (genetic and physiological) and extrinsic (management and climatic) factors. Collectively, this research provides novel dataset combining physiological, molecular epigenetics, and digital tracking indices that advances our understanding of how Merino ewes respond to shearing frequency, and this information could guide further research on Merino sheep breeding and welfare.

Linking the roles of personality and stress physiology for managing the welfare of captive big cats

Animal welfare is important for the humane treatment of animals under our care. Zoos and rescue centres manage various charismatic animals, such as big cats, with limited resources. It is therefore essential for caretakers to understand the needs of an individual big cat to ensure its welfare. However, these needs may differ due to a big cat's personality, which may be identified by its coping style in a stressful situation. In addition, stress is one of the major factors affecting animal welfare. There is limited evidence showing strong associations between personality and stress physiology in big cats. This review focuses on the integration of personality and stress physiology of captive big cats, to highlight possible improvements in their husbandry. Our review identifies key factors that may influence big cat responses to stressors. These influencing factors include: i) social interactions; ii) environment; iii) life history and evolutionary traits; iv) genetics; and v) health. The first two factors are relatively well covered in the literature; however, the final three are potentially very promising avenues for future research to better understand how we can improve big cat welfare.

Pre- and post-partum variation in wool cortisol and wool micron in Australian Merino ewe sheep (Ovis aries)

An individual merino sheep’s output of wool production is influenced by synergistic interactions of sheep genetics, climate, farm management, and nutrition available to the whole flock. The price paid to the producer for this wool commodity is determined via numerous tested parameters and /or subjective appraisal of the raw greasy wool. This research investigated the level of variation in wool cortisol (a physiological stress biomarker) and wool micron (MIC) in Merino ewes (Ovis aries), pre-partum and post-lambing (lactation/lambs at foot), using maiden ewe (n = 38) managed in an outdoor paddock in a commercial farm. The key findings of this study are; (1) wool quality indicators showed a significant variation between pre- and post- parturition including significant reduction in MIC and (2) there was a negative correlation between wool cortisol levels and wool micron pre-parturition (rs = − 0.179, p < 0.05). This relationship between wool cortisol and wool micron was positive (rs = + 0.29, p < 0.05) during post-parturition suggesting that ewes with lambs at foot ended up with finer wool (reduction in fibre diameter) but they also maintained high levels of wool cortisol. Furthermore, the comfort factor, curvature, standard deviation and spin fineness of the wool were also significantly reduced post-parturition. The results of this study show that metabolic resources partitioning in ewe associated with pregnancy and lambing can result in a reduction in wool quality indices. The activity of the HPA-axis is attenuated during late gestation and parturition as a maternal adaptation; however, the results of our study show that wool cortisol remained similar between pre- and post- lambing. This result indicates that environmental stressors that may have been operating on farm (e.g., cold winter period) could influence on maternal physiological stress response however the exact level of influence of environment conditions on ewe stress levels and productivity traits (e.g., lambing success and wool quality) warrants further investigation. In conclusion, the use of top-knot wool sampling in combination with wool cortisol analysis provides researchers with a convenient method to quantify wool quality and physiological stress simultaneously under commercial sheep production.

Chronic elevation of plasma cortisol causes differential expression of predominating glucocorticoid in plasma, saliva, fecal, and wool matrices in sheep

There is increasing interest in using nonblood measures of glucocorticoids to assess the physiological response to chronic stress conditions. In sheep, cortisol has been measured in various matrices including saliva, feces, and wool, but comprehensive studies of the relationship between plasma concentrations of cortisol and concentrations in these nonblood matrices are lacking. Therefore, we tested the hypothesis that administration of cortisol to sheep would result in elevated concentrations of cortisol in blood, saliva, feces, and wool. Merino ewes were administered with saline or 2 mg/kg BW/d hydrocortisone acetate (HCA) by intramuscular (i.m.) injection for 28 d. This treatment was imposed to mimic circulating cortisol concentrations experienced during periods of chronic stress. Cortisol and cortisone were directly measured in plasma, saliva, and wool before, during, and after treatment with saline or HCA. A 14-d pre-treatment and a 14-d post-treatment period were used to measure time taken for glucocorticoid concentrations in each of the matrices to return to baseline levels. Cortisol was also measured in feces before, during, and after treatment. Wool growth was also measured. Before treatment, there was no difference in the concentration of cortisol or cortisone in plasma, saliva, feces, or wool in animals treated with saline or HCA. In contrast, treatment with HCA increased (P < 0.05) concentrations of both cortisol and cortisone in plasma, saliva, and wool and of cortisol in feces. In plasma, cortisol concentrations were higher than cortisone (P < 0.05), whereas saliva cortisol and cortisone concentrations did not differ significantly. In wool, the concentration of cortisone was about 19-fold higher than that of cortisol during treatment and post-treatment periods. Treatment with HCA inhibited wool growth. These results demonstrate that an increase in glucocorticoids in the blood of sheep is reflected in increases in saliva (after 7 d of treatment), feces (21 d), and wool (14 d). Therefore, measures of glucocorticoids in these matrices may provide a measure of activation of the adrenal glands over time in sheep, thereby providing a retrospective indicator of chronic stress. With respect to wool, it appears that cortisol is predominantly metabolized to cortisone in the skin or wool follicle and is stored as cortisone. Therefore wool cortisone may also provide an important measure in quantifiying chronic stress in sheep.

A 29-year retrospective analysis of koala rescues in New South Wales, Australia

The koala (Phascolarctos cinereus) is currently listed by both the IUCN and the Australian Governments' Threatened Species Scientific Committee as vulnerable to extinction with an overall decreasing population trend. It is unknown exactly how many koalas remain in the wild, but it is known that habitat fragmentation and bushfires have ultimately contributed to the decline of the koala all over Australia. This novel study is a retrospective analysis of data over a 29-year period (1989-2018) using records for 12,543 sightings and clinical care admissions for wild koalas from the major koala hot-spots (Port Stephens, port Macquarie and Lismore) in New South Wales, Australia. This study aims to understand the long-term patterns and trends of key stressors that are contributing to the decline of koalas in New South Wales, and the synergic interactions of factors such as rescue location, sex and age of the koala, and if their decline is influenced progressively by year. The main findings of this retrospective analysis indicated that between all 3 rescue sites, the most common prognosis was disease, the most common disease was signs of chlamydia, and the most common outcome was release. The location where the highest number of koalas were found prior to being reported as sighted or admitted into clinical care was within the regional area of Lismore. Furthermore, sex was not a discriminating factor when it came to prognosis or outcome, but age was significant. Finally, incidents of disease were found to increase over long-term, whereas release decreased over time and euthanasia increased. The wealth of data available to us and the retrospective analysis enabled us in a way to 'zoom out' and reveal how the key environmental stressors have fluctuated spatially and temporally. In conclusion, our data provides strong evidence of added pressures of increased human population growth in metropolitan zones, which increases risks of acute environmental trauma and proximate stressors such as vehicle collisions and dog-attacks as well as increased sightings of virtually healthy koalas found in exposed environments. Thus our 'zoom out' approach provides support that there is an urgent need to strengthen on-ground management, bushfire control regimes, environmental planning and governmental policy actions that should hopefully reduce the proximate environmental stressors in a step wise approach. This will ensure that in the next decade (beyond 2020), NSW koalas will hopefully start to show reversed trends and patterns in exposure to environmental trauma and disease, and population numbers will return towards recovery and stability.

Identifying the Stressors Impacting Rescued Avian Wildlife

Simple Summary

Stress evaluation in wildlife is valuable tool for rehabilitation and injury prevention. This pilot study investigated categories of stress in rescued birds. We determined three categories of stressors (preliminary, primary and secondary) using clinical data of rescued birds from Adelaide, South Australia. It was discovered that birds are highly susceptible to impact injuries (e.g., flying into a building window) and vehicle-related injuries as preliminary stressors, which often result in hospitalisation of birds. Immobility and abnormal behaviour represented the most common primary stressor, while the most common secondary stressors included trauma and fracture. Furthermore, the most common outcome in clinics due to exposure of birds to these three stressor categories was euthanasia.

Abstract

Urbanisation exposes avian wildlife to an array of environmental stressors that result in clinical admission and hospitalisation. The aim of this pilot study was to conduct a retrospective analysis of clinical data and characterise this based on categories of stress experienced by avian wildlife patients. The results from this study indicated that impact injuries (n = 33, 25%) and vehicle-related injuries (n = 33, 25%) were the most common occurring preliminary stressors that resulted in the hospitalisation of avian wildlife. The most common outcome of avian patients that suffered from vehicle-related injuries was euthanasia (n = 15, 45%), as was avian patients that suffered from impact injuries (n = 16, 48%). Immobility (n = 105, 61%) and abnormal behaviour (n = 24, 14%) were the most commonly occurring primary stressors of avian patients. Finally, trauma (n = 51, 32%) and fractures (n = 44, 27%) were the most common occurring secondary stressors in avian patients. The most common outcome of all these stressors was euthanasia. This study provided further evidence towards the notion that human- and urbanisation-related stressors are the main causes of hospitalisation of avian wildlife, but also indicated that birds admitted as a result of human-related stressors are more likely to be euthanised than released. This study also provided a categorisation system for the stressors identified in avian wildlife patients (preliminary, primary and secondary) that may be used to monitor the stress categories of wildlife patients and gain a deeper understanding of the complex notion of stress.

Using Thermal Imaging to Monitor Body Temperature of Koalas (Phascolarctos cinereus) in A Zoo Setting

Non-invasive techniques can be applied for monitoring the physiology and behaviour of wildlife in Zoos to improve management and welfare. Thermal imaging technology has been used as a non-invasive technique to measure the body temperature of various domesticated and wildlife species. In this study, we evaluated the application of thermal imaging to measure the body temperature of koalas (Phascolarctos cinereus) in a Zoo environment. The aim of the study was to determine the body feature most suitable for recording a koala's body temperature (using coefficient of variation scores). We used a FLIR530TM IR thermal imaging camera to take images of each individual koala across three days in autumn 2018 at the Wildlife Sydney Zoo, Australia. Our results demonstrated that koalas had more than one reliable body feature for recording body temperature using the thermal imaging tool-the most reliable features were eyes and abdomen. This study provides first reported application of thermal imaging on an Australian native species in a Zoo and demonstrates its potential applicability as a humane/non-invasive technique for assessing the body temperature as an index of stress.

Cortisol Measurement in Koala (Phascolarctos cinereus) Fur

Optimal methods of hormone extraction used to measure stress in animals across sample types are not always the same. Australia's iconic marsupial species, the koala (Phascolarctos cinereus), faces prolonged exposure to anthropogenic-induced stressors and assessment of chronic stress in wild populations is urgently warranted. One of the most effective ways to measure chronic stress is through analyzing the glucocorticoid hormone cortisol in hair or fur, as it supports physiological and behavioral responses. This laboratory validation study aims to test current techniques to validate an optimal hormone extraction method to be used as a non-invasive measure of cortisol in koala fur. It is recognized that using non-invasive techniques to measure stress hormones is preferred over traditional, invasive techniques due to their ideal practical and ethical standpoints. Additionally, it is comparatively easier to acquire fur from koalas than it is to acquire samples of their blood. This study used samples of koala fur acquired from the Adelaide Koala and Wildlife Hospital to run a number of hormone extraction techniques in an attempt to validate an optimal cortisol extraction method. Results showed that 100% methanol provided the most optimal solvent extraction compared to 100% ethanol or 100% isopropanol based on parallelism results. In conclusion, this method of cortisol extraction from koala fur provided a reliable non-invasive assay that could be used to study chronic stress in koalas.

Physiological stress levels in wild koala sub-populations facing anthropogenic induced environmental trauma and disease

Australian small mammals such as koalas must cope with immense pressure from anthropogenic induced stressors or trauma such as bushfires, vehicle collision impacts and habitat disturbance and land clearance. In addition, they must cope with diseases such as chlamydia. To date, there is no published literature on physiological stress levels in wild koala populations compared with identified environmental stressors. This study investigated physiological stress levels within sub-populations of wild koalas encountering environmental trauma and disease from New South Wales (NSW), Queensland (QLD) and South Australia (SA). Physiological stress was determined using a faecal glucocorticoid (or cortisol) metabolites (FGMs) enzyme-immunoassay (EIA) from 291 fresh faecal samples collected from wild koalas at the point of rescue. A healthy breeding sub-population from a forest reserve in QLD acted as a control group. Clearance of prime Eucalyptus habitat had the largest impact on FGMs, followed by bushfire related factors (e.g. flat demeanour, dehydration and burns injury). Koalas with other sources of physical injury (dog-attacks and vehicle collisions) and disease (chlamydia) also had higher FGMs compared to healthy wild koalas. Healthy wild koalas expressed the lowest median levels of FGMs. Overall, the results highlight that anthropogenic-induced stressors tend to increase physiological stress in wild koalas. Thus, the ultimate stressors such as habitat clearance and bush fire events could increase the incidences of proximate stressors such as dog attacks and vehicle collisions, and increase risks of foliage shortage, diseases and mortality. Therefore, there is need for ecological monitoring, conservation management actions and policy changes to curb the koala population crisis, especially within on-going and future land and road development programs.

Physiological Stress in Rescued Wild Koalas Are Influenced by Habitat Demographics, Environmental Stressors, and Clinical Intervention

Koalas are rescued from the wild often with incidence of burns from bushfire, injury from animal attacks, vehicle collision, and diseases. Exposure to environmental stressors (trauma and disease) could generate physiological stress and potentially impact the outcomes of clinical management intervention and rehabilitation of rescued wild koalas. It is important to quantify the stress physiology of wild koalas upon registering into clinical care. This study demonstrates the first report of physiological stress assessment in rescued wild koalas (n = 22) to determine the potential influences of habitat-specific demographics, stressor category, and clinical diagnosis. Fecal samples were collected from the koalas at rescue and routinely during hospitalization to provide a longitudinal assessment of the koala's stress response throughout clinical care. Fecal glucocorticoid metabolites (FCM) enzyme-immunoassay was used to index physiological stress non-invasively. Koalas were admitted with exposure to various categories of environmental trauma such as vehicle collision, dog attack, burns from forest fire (this also related to conditions such as copious drinking and flat demeanor), and other injury. The main disease diagnosed was chlamydial infections. In terms of environmental interactions, it was found that habitat-specific demographics, location where the rescued koala was found, especially the rural-urban fringe, influenced FCM levels. Furthermore, there was significant interaction between location, stressor category, and clinical diagnosis for mean FCM levels. However, these factors were not predictive of the clinical outcome (euthanized or released). Overall, the results provide invaluable insights into how wild koalas respond physiologically to environmental trauma and disease and how methods of care, husbandry, and treatment can be used to further reduce the impacts of stress with the ultimate aim of increasing the rehabilitation and future release of rescued koalas to revive the declining mainland populations.

Faecal glucocorticoid metabolites and body temperature in Australian merino ewes (Ovis aries) during summer artificial insemination (AI) program

Reproductive wastage is a key issue for sheep producers, both regionally and globally. The reproductive output of farm animals can be influenced by physiological and environmental factors. Rapid and reliable quantification of physiological stress can provide a useful tool for designing and testing on-farm management interventions to improve farm animal welfare and productivity. In this study, we quantified physiological stress non-invasively using faecal glucocorticoid metabolites-FGMs analysis and body temperature measurements of 15 superovulated donor merino ewes (Ovis aries) during participation in artificial insemination (AI) program conducted during 2015/2016 Australian summer. We hypothesized that low percentage transferable embryos in donor merino ewes will be associated positively with higher body temperature and/or higher FGMs in these ewes. Temperature humidity index (THI) was calculated and found within high thermal stress range during the two AI trials. Overall, results showed none of the factors (ewe ID, AI trial no., THI or FGMs) were significant for reduced percentage transferrable embryos, except ewe body temperature was highly significant (p = 0.014). Within AI trial comparisons showed significant positive associations between higher FGMs and body temperature with reduced transferrable embryos. These results suggest that Australian merino ewes participating in summer AI trials can experience physiological stress. Prolonged activation of the stress endocrine response and high body temperature (e.g. ensued from heat stress) could impact on ewe reproductive output. Therefore, future research should apply minimally invasive physiological tools to gather baseline information on physiological stress in merino sheep to enable the development of new farm-friendly methods of managing stress.

Sarcoptic mange in wombats-A review and future research directions

Sarcoptic mange is caused by the mite Sarcoptes scabiei and has recently been recognized as an emerging infectious disease of wildlife worldwide. The mite is one of the main causes of population decline in southern hairy-nosed (Lasiorhinus latifrons) and bare-nosed wombats (Vombatus ursinus). This review focuses on Sarcoptes scabiei infestations in wombats and provides insights into why the disease may be so prevalent in wombats. Current treatment practices and trials conducted in the field to reduce the incidence of sarcoptic mange in wombats are described and critically reviewed. Current and potential future avenues of research are discussed.

Fecal glucocorticoid metabolite response of captive koalas (Phascolarctos cinereus) to visitor encounters

Physiological responses of wildlife species to zoo visitors should be studied to better understand how wildlife perceive human encounters. We conducted an experimental test of the effect of changes in zoo visitor encounter experiences on the glucocorticoid (GC) response of koalas (Phascolarctos cinereus) in a Sydney zoo. Koalas were housed in a multiple-bay enclosure (two to three koalas per bay) for photography sessions with zoo visitors (no touching of koalas permitted by visitors). Following a one-week no-photography baseline period, photography sessions were rotated between three enclosure bays for four weeks (Intensive photography), then between five enclosure bays for an additional four weeks (Standard photography). A sixth enclosure bay was never included in the photography sessions (control bay); koalas in this bay showed no significant change in fecal cortisol metabolites (FCMs) during the course of the study. In the five experimental bays differences were seen between male and female koalas. Males had higher mean FCMs than females, and individual FCM traces showed that two male koalas that were related and of similar age responded strongly to the experimental manipulation. These two males showed a peak in FCMs at the beginning of the Intensive photography period, then a decline when photography sessions returned to the Standard protocol. No systematic pattern in response to photography sessions was observed in females. Our results demonstrate successful application of a non-invasive endocrinology tool for assessing the stress biology and welfare of captive zoo wildlife.

Host stress physiology and Trypanosoma haemoparasite infection influence innate immunity in the woylie (Bettongia penicillata)

Understanding immune function is critical to conserving wildlife in view of infectious disease threats, particularly in threatened species vulnerable to stress, immunocompromise and infection. However, few studies examine stress, immune function and infection in wildlife. We used a flow cytometry protocol developed for human infants to assess phagocytosis, a key component of innate immunity, in a critically endangered marsupial, the woylie (Bettongia penicillata). The effects of stress physiology and Trypanosoma infection on phagocytosis were investigated. Blood and faecal samples were collected from woylies in a captive facility over three months. Trypanosoma status was determined using PCR. Faecal cortisol metabolites (FCM) were quantified by enzyme-immunoassay. Mean phagocytosis measured was >90%. An interaction between sex and FCM influenced the percentage of phagocytosing leukocytes, possibly reflecting the influence of sex hormones and glucocorticoids. An interaction between Trypanosoma status and FCM influenced phagocytosis index, suggesting that stress physiology and infection status influence innate immunity.

A review of factors influencing the stress response in Australian marsupials

Many Australian marsupials are threatened species. In order to manage in situ and ex situ populations effectively, it is important to understand how marsupials respond to threats. Stress physiology (the study of the response of animals to challenging stimuli), a key approach in conservation physiology, can be used to characterize the physiological response of wildlife to threats. We reviewed the literature on the measurement of glucocorticoids (GCs), endocrine indicators of stress, in order to understand the stress response to conservation-relevant stressors in Australian marsupials and identified 29 studies. These studies employed a range of methods to measure GCs, with faecal glucocorticoid metabolite enzyme immunoassay being the most common method. The main stressors considered in studies of marsupials were capture and handling. To date, the benefits of stress physiology have yet to be harnessed fully in marsupial conservation. Despite a theoretical base dating back to the 1960s, GCs have only been used to understand how 21 of the 142 extant species of Australian marsupial respond to stressors. These studies include merely six of the 60 marsupial species of conservation concern (IUCN Near Threatened to Critically Endangered). Furthermore, the fitness consequences of stress for Australian marsupials are rarely examined. Individual and species differences in the physiological stress response also require further investigation, because significant species-specific variations in GC levels in response to stressors can shed light on why some individuals or species are more vulnerable to stress factors while others appear more resilient. This review summarizes trends, knowledge gaps and future research directions for stress physiology research in Australian marsupial conservation.

Urinary corticosterone responses and haematological stress indicators in the endangered Fijian ground frog (Platymantis vitiana) during transportation and captivity

Physiological stress assessment is important for in-situ conservation and captive management of threatened wildlife. Leukocyte (white blood cell) evaluation, especially the neutrophil : lymphocyte (N : L) ratio, provides a logical representation of experimentally elevated corticosterone (stress hormone) in amphibians. Urinary corticosterone enzyme-immunoassay (EIA) is a rapid non-invasive tool for assessing stress responses in amphibians. To our knowledge, no one has explored the relationship between N : L ratio and urinary corticosterone in wild amphibians in a non-experimental way. This study provides a comparative assessment of relative leukocyte numbers, N : L ratios and urinary corticosterone responses of the endangered Fijian ground frog (Platymantis vitiana) during transportation and captivity. Adult frogs (n = 40) were collected from Viwa, Fiji Island for captive breeding. Frogs showed significant changes in leukocyte proportions during transportation and captivity. N : L ratios were higher 6 h after transportation and over 5 and 15 days in captivity. Urinary corticosterone responses of the frogs were also higher 6 h after transportation and after 5 and 15 days in captivity. All leukocyte proportions, N : L ratios and urinary corticosterone concentrations of the frogs returned near baseline levels after the frogs were kept in an environmentally enriched outdoor enclosure for over 25 days. These results highlight the value of leukocyte evaluation and urinary corticosterone EIAs as physiological tools for evaluating stress in amphibians.

Urinary corticosterone metabolite responses to capture, and annual patterns of urinary corticosterone in wild and captive endangered Fijian ground frogs (Platymantis vitiana)

This study was based on the development of a non-invasive glucocorticoid enzyme-immunoassay for the assessment of stress in wild and captive endangered Fijian ground frogs (Platymantis vitiana). Enzyme-immunoassays were developed and validated for the first time to non-invasively measure both cortisol and corticosterone metabolites in frog urine. Frog urine showed parallel displacement with corticosterone but not cortisol standards, therefore corticosterone enzyme immunoassays were used to examine stress in wild and captive frogs. Urinary corticosterone metabolite concentrations increased in frog urine (n = 4) at 6 h, 1 day and 2 days after injection with adrenocorticotropic hormone (0.44 μg g–1 bodyweight), indicating that the corticosterone enzyme-immunoassay could detect changes in circulating corticosterone in frogs. Urinary concentrations of corticosterone were measured in wild frogs (n = 18) after capture in the field. The first measurement beyond the initial sample was at 2–3 h. Mean urinary corticosterone concentrations rose after the initial sample and were significantly elevated in samples collected 3–4 h after capture. This is the first demonstration of a urinary corticosterone response to capture in amphibians. Urinary corticosterone metabolite concentrations for all months combined were lower in captive males than in wild males, and differed between vitellogenic, non-vitellogenic and captive females. Concentrations did not differ between captive and wild females. In conclusion, urinary corticosterone enzyme immunoassays can be used in frogs for assessing stress responses to capture and natural stress profiles of both captive and wild populations.

Captive propagation of the endangered native Fijian frog Platymantis vitiana: Implications for ex-situ conservation and management

We present research and management implications for captive propagation of the endangered Fijian Ground Frog Platymantis vitiana to develop methods for supplementing populations in the wild. In 2004, a captive propagation program was instituted at Kula Ecopark, Sigatoka, Fiji. However, there was little success with only a single froglet reared after three years. In 2006, a more intensive programme was undertaken between the University of the South Pacific (USP), Kula Ecopark and the community on Viwa Island. The aim of this programme was to create an outdoor enclosure to mimic natural habitat conditions so the frogs could exhibit natural breeding behaviour. A total of 39 froglets was reared after one year of this programme. We provide information on the methods of captive management, reproductive biology, captive diet varieties, and on problems of rearing froglets in captivity. This research is useful baseline information in guiding captive propagation techniques in zoological parks like the Kula Ecopark and for organizations such as the National Trust of Fiji.

Cell block cytology. Improved preparation and its efficacy in diagnostic cytology

Cell blocks prepared from residual tissue fluids and fine-needle aspirations can be useful adjuncts to smears for establishing a more definitive cytopathologic diagnosis. They can be particularly useful for categorization of tumors that otherwise may not be possible from smears themselves. A modified cell block technique using an improvised ethanol formalin fixative (Nathan alcohol formalin substitute) followed by a simple paraffin processing schedule is described. This improved preparation offers excellent cytomorphologic features corresponding closely to cells in Papanicolaou-stained smears and ensures optimal preservation of histochemical and immunocytochemical properties. The technique is simple and reproducible and uses routine safe laboratory chemicals. The efficacy of cell blocks also is discussed.