Search

Large herbivores typically have consistently high prime‐aged adult survival and lower, more variable, juvenile, and senescent survival. Many kangaroo populations undergo greater fluctuations in density compared with other large herbivores, but age‐ and sex‐specific survival of kangaroos and their response to environmental variation remain poorly estimated. We used long‐term capture–mark–recapture data on 920 individuals to investigate the survival component of eastern grey kangaroo (Macropus giganteus) population dynamics. Forage availability and population density were monitored quarterly and included as predictors of survival in Bayesian Cormack–Jolly–Seber models. Annual survival probabilities were estimated for five age classes: 0 years (juveniles), 1–2 years (subadults), 3–6 years (prime‐aged adults), 7–9 years (presenescent adults), and ≥10 years (senescent adults). Survival of juveniles varied widely during our 12‐year study, ranging from 0.07 to 0.90 for females and 0.05–0.92 for males. Subadult survival was 0.80–0.93 for females and 0.75–0.85 for males, while that of prime‐aged adults was ≥0.94 for females and ≥0.83 for males, despite large fluctuations in forage and density. The survival of presenescent adults spanned 0.86–0.93 for females and 0.60–0.86 for males. Senescent survival was variable, at 0.49–0.90 for females and 0.49–0.80 for males. Male survival was significantly lower than female survival in prime‐aged and presenescent adults, but not in other age classes. Although most of the models supported by Watanabe–Akaike Information Criterion selection included at least one environmental covariate, none of these covariates individually had a discernible effect on survival. Temporal variability in overall survival appeared mostly due to changes in the survival of juvenile and senescent kangaroos. Kangaroo survival patterns are similar to those of ungulates, suggesting a strong role of sex–age structure on population dynamics. [ABSTRACT FROM AUTHOR]

A central goal of ecology is to understand how environmental variation affects populations. Long-term studies of marked individuals can quantify the effects of environmental variation on key life-history traits. We monitored the survival and growth of 336 individually marked juvenile eastern grey kangaroos (Macropus giganteus), a large herbivore living in a seasonal but unpredictable environment. During our 12-year study, the population experienced substantial variation in rainfall, forage biomass, and density. We used structural equation modeling to determine how variation in temperature and rainfall affected juvenile survival and growth through its effect on forage biomass and population density. Independently of population density, forage biomass had strong positive effects on survival from 10 to 21 months. At low population density, forage biomass also had a positive effect on skeletal growth to 26 months. Increasing maternal body condition improved rearing success for daughters but not for sons. High population density reduced skeletal growth to 26 months for both sexes. Rainfall had an increasingly positive effect on forage biomass at high temperatures, indicating a seasonal effect on food availability. Our study reveals interacting effects of environmental variation on juvenile survival and growth for a large mammal with a conservative reproductive strategy that experiences substantial stochasticity in food availability. [ABSTRACT FROM AUTHOR]

Knowledge of animal responses to fire is fundamental to wildlife management in fire‐prone ecosystems. Fire can influence the occurrence of large herbivores by altering the structure and composition of vegetation. However, how fire affects herbivore occurrence in many ecosystems is poorly understood. Large herbivores may be attracted to burnt areas due to higher foraging quality. Conversely, herbivores may avoid burnt areas due to heightened predation risk. We tested the influence of vegetation type and fire history variables on the occurrence of macropods at Booderee National Park in south‐eastern Australia. We documented macropod occurrence at 107 long‐term monitoring sites using spotlighting surveys conducted between 2003 and 2019. We modelled relationships between the occurrence of the eastern grey kangaroo (Macropus giganteus) and the swamp wallaby (Wallabia bicolor) with three fire history variables; time since fire, fire frequency and burn context (the proportion of the area surrounding each site that was recently burnt), as well as their interaction with vegetation type. We found both macropod species selected recently burnt sites, likely due to a higher abundance of preferred plants at these sites. Increasing fire frequency was associated with a reduced occurrence of the eastern grey kangaroo. The occurrence of both macropod species was significantly higher in forest sites, possibly reflecting higher foraging quality of grass and shrub species compared to woodland, heathland and shrubland sites. We suggest that if fire is used as a management tool, it is important to recognise potential feedbacks from increased foraging pressure from large herbivores. Future fire management will need to avoid burning areas of sensitive vegetation if local herbivores display pyric herbivory responses, and/or avoid small‐scale burns, which may concentrate foraging pressure. [ABSTRACT FROM AUTHOR]

Virtual wildlife fencing presents as a cost-effective measure for roadkill mitigation, which aids in reducing fragmentation of wildlife populations by facilitating safer movement of wildlife across the landscape. In this study, we conducted an audit of a virtual fence installation in south-east Queensland, Australia. We assessed its reliability in flows of traffic and the effect that installation parameters and site conditions had on its effective operation in an urban setting. We made observations on the behavioural response of Eastern Grey Kangaroos Macropus giganteus to the acoustic signals produced by the fence. We found that the fencing activated consistently in response to headlights at dusk and dawn, and when traffic flows were dense, despite considerable variations in the range of installation parameters. However, we identified that the response of the virtual fence to headlights was affected by road curvature and we identified inconsistencies in the timing and pattern of activation in response to traffic. Behavioural observations showed a significant increase in kangaroo vigilance in response to the acoustic signal of the fence when resting or grazing, and kangaroos detected the acoustic signal up to 50 m away. While virtual fencing operates effectively and is a low-cost roadkill mitigation option that can be applied to the urban environment, more research is needed to better understand the effect of its acoustic and visual signals on wildlife behaviour and efficacy in busy urban environments. [ABSTRACT FROM AUTHOR]

Abstract Background Enterocytozoon bieneusi is a microsporidian, commonly found in animals, including humans, in various countries. However, there is scant information about this microorganism in Australasia. In the present study, we conducted the first molecular epidemiological investigation of E. bieneusi in three species of marsupials (Macropus giganteus, Vombatus ursinus and Wallabia bicolor) living in the catchment regions which supply the city of Melbourne with drinking water. Methods Genomic DNAs were extracted from 1365 individual faecal deposits from these marsupials, including common wombat (n = 315), eastern grey kangaroo (n = 647) and swamp wallaby (n = 403) from 11 catchment areas, and then individually tested using a nested PCR-based sequencing approach employing the internal transcribed spacer (ITS) and small subunit (SSU) of nuclear ribosomal DNA as genetic markers. Results Enterocytozoon bieneusi was detected in 19 of the 1365 faecal samples (1.39%) from wombat (n = 1), kangaroos (n = 13) and wallabies (n = 5). The analysis of ITS sequence data revealed a known (designated NCF2) and four new (MWC_m1 to MWC_m4) genotypes of E. bieneusi. Phylogenetic analysis of ITS sequence data sets showed that MWC_m1 (from wombat) clustered with NCF2, whereas genotypes MWC_m2 (kangaroo and wallaby), MWC_m3 (wallaby) and MWC_m4 (kangaroo) formed a new, divergent clade. Phylogenetic analysis of SSU sequence data revealed that genotypes MWC_m3 and MWC_m4 formed a clade that was distinct from E. bieneusi. The genetic distinctiveness of these two genotypes suggests that they represent a new species of Enterocytozoon. Conclusions Further investigations of Enterocytozoon spp. from macropods and other animals will assist in clarifying the taxonomy and epidemiology of these species in Australia and elsewhere, and in assessing the public health risk of enterocytozoonosis.

Life history theory predicts trade-offs in allocation between survival, maintenance, growth, and reproduction, especially when resources are scarce. Individual variation in resource acquisition can affect trade-offs, but is often unaccounted for. We quantified the fitness costs of reproduction, accounting for environmental conditions, maternal characteristics and individual variation. We analyzed 10 years of data from marked kangaroos to evaluate how reproductive allocation affected annual mass change and skeletal growth, subsequent fecundity and weaning success, and survival, accounting for maternal mass or size and forage availability. Through repeated measurements of 76–91 females, we investigated how trade-offs varied within and between individuals, assessing whether individual variation could mask population-level trade-offs. In poor environments, females that weaned an offspring lost mass. Females that nursed an offspring for > 7 months had reduced skeletal growth. Females that did not gain mass over the previous 12 months rarely reproduced, especially if they had nursed an offspring for > 7 months the previous year. Reproductive allocation had no effect on weaning success, which was very low, and did not affect maternal survival, suggesting a conservative strategy. Disentangling within- and between-individual responses revealed trade-offs within individuals, but because individuals did not vary in their responses to earlier effort, these trade-offs did not drive population trends. The interacting effects of environmental conditions, maternal characteristics and individual variation on allocation trade-offs demonstrate the importance of long-term monitoring for understanding life history variations in changing environments. [ABSTRACT FROM AUTHOR]

Urbanization significantly impacts the health and viability of wildlife populations yet it is not well understood how urban landscapes differ from non‐urban landscapes with regard to their effects on wildlife. This study investigated the physiological response of eastern grey kangaroos (Macropus giganteus) to land use at a landscape scale. Using fecal glucocorticoid metabolites (FGM) we compared stress levels of kangaroo populations in urban and non‐urban environments. We modeled FGM concentrations from 24 kangaroo populations against land use (urban or non‐urban) and other anthropogenic and environmental factors, using a linear modeling approach. We found that land use was a significant predictor of FGM concentrations in eastern grey kangaroos with significant differences in concentrations between urban and non‐urban populations. However, the direction of the relationship differed between northern and southern regions of Australia. In the northern study sites, kangaroos in urban areas had significantly higher FGM levels than their non‐urban counterparts. In contrast, in southern sites, where kangaroos occur in high densities in many urban areas, urban kangaroos had lower FGM concentrations than non‐urban kangaroos. Rainfall and temperature were also significant predictors of FGM and the direction of the relationship was consistent across both regions. These results are consistent with the contrasting abundance and persistence of kangaroo populations within the urban matrix between the two study regions. In the northern region many populations have declined over the last two decades and are fragmented, also occurring at lower densities than in southern sites. Our study indicates that it is the characteristics of urban environments, rather than the urban environment per se, which determines the extent of impacts of urbanization on kangaroos. This research provides insights into how the design of urban landscapes can influence large mammal populations. [ABSTRACT FROM AUTHOR]

Extreme climatic events such as droughts and floods are expected to become more intense and severe under climate change, especially in the southern and eastern parts of Australia. We aimed to quantify the relationship between body condition scores (BCS), demography, activity rate, and parasitic infections of eastern grey kangaroos on a large conservation property under different climate extremes by employing camera traps established at artificial water points (AWPs). The survey period included a severe drought, broken by a significant flooding event. Climatic and environmental conditions were documented using remotely sensed indices of moisture availability and vegetation productivity. These conditions were found to affect all health and population parameters measured. BCS, juvenile proportions, and sex ratios were most correlated with 6-month lags in climatic conditions, while the activity rate of kangaroos at AWPs was most correlated with vegetation productivity. Ticks were mostly found on individuals with a poorer BCS, while the concentration of parasitic eggs in feces was higher in autumn than in spring. Our study offers a glimpse into some of the environmental drivers of eastern grey kangaroo populations and their health, information that may become increasingly important in today’s climate. It further emphasizes the importance of this knowledge for wildlife conservation efforts appropriate to managing the impact of climate change alongside other threats.

Social network analysis has been postulated as a tool to study potential pathogen transmission in wildlife but is resource‐intensive to quantify. Networks based on bacterial genotypes have been proposed as a cost‐effective method for estimating social or transmission network based on the assumption that individuals in close contact will share commensal bacteria. However, the use of network analysis to study wild populations requires critical evaluation of the assumptions and parameters these models are founded on.We test (a) whether networks of commensal bacterial sharing are related to hosts' social associations and hence could act as a proxy for estimating transmission networks, (b) how the parameters chosen to define host associations and delineate bacterial genotypes impact inference and (c) whether these relationships change across time. We use stochastic simulations to evaluate how uncertainty in parameter choice affects network structure.We focused on a well‐studied population of eastern grey kangaroos (Macropus giganteus), from Sundown National Park, Australia. Using natural markings, each individual was identified and its associations with other kangaroos recorded through direct field observations over 2 years to construct social networks. Faecal samples were collected, Escherichia coli was cultured and genotyped using BOX‐PCR, and bacterial networks were constructed. Two individuals were connected in the bacterial network if they shared at least one E. coli genotype. We determined the capacity of bacterial networks to predict the observed social network structure in each year.We found little support for a relationship between social association and dyadic commensal bacterial similarity. Thresholds to determine host associations and similarity cut‐off values used to define E. coli genotypes had important ramifications for inferring links between individuals. In fact, we found that inferences can show opposite patterns based on the chosen thresholds. Moreover, no similarity in overall bacterial network structure was detected between years.Although empirical disease transmission data are often unavailable in wildlife populations, both bacterial networks and social networks have limitations in representing the mode of transmission of a pathogen. Our results suggest that caution is needed when designing such studies and interpreting results. [ABSTRACT FROM AUTHOR]

An adult female Eastern Grey kangaroo (Macropus giganteus) was examined for lameness due to a mass located at the right tibiotarsal joint. Radiographs revealed a metal arrowhead‐shaped foreign body within the mass alongside a pathologic fracture. Grossly, at necropsy, there was a multilobulated and haemorrhagic mass with intralesional metal fragments, associated osteolysis of the tibiotarsus and pulmonary metastatic nodules. Histologically the neoplasm was composed of plump elongated and fusiform cells that often formed concentrically around small vessels. The pulmonary nodules were composed of similar neoplastic cells, necrosis and haemorrhage. Neoplastic cells were positive immunohistochemically for vimentin and smooth muscle actin. The histological features, immunohistochemical profiles and behaviour of this tumour support a diagnosis of a primary angioleiomyosarcoma with lung metastasis associated with a metal foreign body. [ABSTRACT FROM AUTHOR]

Abstract Vegetation contaminated by industrial fluoride emissions can cause disease in herbivorous mammals. Spatially explicit exposure models offer a quantitative approach for evaluating and managing the potentially toxic effects of chronic fluoride consumption on wildlife. We monitored eastern grey kangaroos (Macropus giganteus) inhabiting a high-fluoride environment in the buffer zone of an aluminium smelter in southeastern Australia between 2010 and 2013. We measured fluoride levels at 19 pasture sites and determined the foraging range of 37 individual kangaroos. A series of generalised linear models were developed to estimate bone fluoride accumulation as a function of pasture exposure. Model outputs were compared to identify the most appropriate predictive tool for kangaroo bone fluoride accumulation relative to exposure. Accounting for age there was a negative association between bone fluoride concentration and distance of the central emission point from both the mean centre of foraging range and the point of death. The mean foraging range centre was the best predictor, with point of death just as suitable (and simpler), whereas more complex parameters such as monthly and cumulative fluoride exposure were poor predictors of bone fluoride concentration. The more complex dietary fluoride exposure estimates did not improve predictive capability compared with the simple, spatial models. We conclude that in actively managed wildlife populations, simple, locally validated models can provide estimates of bone fluoride accumulation sufficient to support decision-making. Graphical abstract Unlabelled Image Highlights • Exposure models can predict toxic effects of fluoride consumption in wildlife. • Exposure models that vary in intensity of field data collection warrant comparison. • Simple spatial metrics can predict fluoride accumulation in a free-ranging mammal. • Complex exposure models may not perform better than simple spatial metrics. [ABSTRACT FROM AUTHOR]

Advances in drone technology have given rise to much interest in the use of drone-mounted thermal imagery in wildlife monitoring. This research tested the feasibility of monitoring large mammals in an urban environment and investigated the influence of drone flight parameters and environmental conditions on their successful detection using thermal infrared (TIR) and true-colour (RGB) imagery. We conducted 18 drone flights at different altitudes on the Sunshine Coast, Queensland, Australia. Eastern grey kangaroos (Macropus giganteus) were detected from TIR (n=39) and RGB orthomosaics (n=33) using manual image interpretation. Factors that predicted the detection of kangaroos from drone images were identified using unbiased recursive partitioning. Drone-mounted imagery achieved an overall 73.2% detection success rate using TIR imagery and 67.2% using RGB imagery when compared to on-ground counts of kangaroos. We showed that the successful detection of kangaroos using TIR images was influenced by vegetation type, whereas detection using RGB images was influenced by vegetation type, time of day that the drone was deployed, and weather conditions. Kangaroo detection was highest in grasslands, and kangaroos were not successfully detected in shrublands. Drone-mounted TIR and RGB imagery are effective at detecting large mammals in urban and peri-urban environments.

The interaction between Eastern Grey Kangaroos (Macropus giganteus) and humans in peri-urban locations is one that excites great passion between conflicting views. Are the kangaroos a problem pest or a diminishing icon? And where conflicts occur between kangaroos, threatened species and ecological communities, and human activities, what is the most acceptable approach to management? A case study to examine this question has been provided by Bathurst Regional Council for the management of the population of Eastern Grey Kangaroos on Mount Panorama, on the doorstep of Bathurst, NSW. In this precinct there are concerns that there may be a collision between a kangaroo and a very fast racing car and that large numbers of kangaroos will have an impact on the survival of an Endangered Ecological Community and agricultural activities on the Mount. In the first instance Bathurst Council enabled the culling of 140 kangaroos and this brought international condemnation. Council then contracted for the development of a Fauna Management Strategy for the Mount but this has not been fully accepted by Council nor implemented. The most recent approach, when Council disturbed the resident kangaroos by clearing a senescent orchard for further development, was resolved by using a community group to relocate at least 300 kangaroos to a location some 100 km to the east. At the time of the relocation this location was in drought and disoriented kangaroos were killed on the road. No information is available for the survival rate of the relocated individuals nor their behaviour post-release. Neither the culling not the relocation of resident Eastern Grey Kangaroos has provided a long-term resolution to the peri-urban conflict between kangaroos and humans on Mount Panorama. Killing is not the answer, neither is relocation. The implementation of the Management Strategy has the potential to provide an intermediate approach. [ABSTRACT FROM AUTHOR]

Objectives: The genetic diversity of an eastern grey kangaroo (Macropus giganteus) population surrounded by landscape barriers was examined. DNA was extracted from tissue samples from 22 road-killed kangaroos, and blood samples from four live captured kangaroos. Amplified loci were used to determine relatedness between individual kangaroos. The level of relatedness and location of road-killed kangaroos were compared to evaluate spatial autocorrelation. Results: The expected and observed heterozygosity confirmed the loci were polymorphic and highly informative for use in this population. One pair of kangaroos were identified to be full siblings, and a high proportion were identified as half siblings. Six positive parentage assignments were detected. No correlation between relatedness and crossing site was detected. [ABSTRACT FROM AUTHOR]

Baseline haematology, blood chemistry and acute phase protein parameters have not previously been published for free-ranging eastern grey kangaroos (Macropus giganteus). Eight eastern grey kangaroos, including three adult males, three adult females and two subadult males from two different populations, were examined. Assays assessed the antibacterial activity of kangaroo serum against one Gram-positive and three Gram-negative bacteria. The kangaroo serum had a strong antibacterial response to Klebsiella pneumoniae, and moderate responses to Escherichia coli and Staphylococcus aureus. The presence and level of acute phase proteins, haptoglobin and serum amyloid A in kangaroos was investigated. Haptoglobin and serum amyloid A were present in kangaroo serum, but only haptoglobin was elevated in a kangaroo with capture myopathy and necrotic wounds. The findings of this study provide preliminary data on health parameters of free-ranging eastern grey kangaroos. These parameters can be used to assist in assessing health in free-ranging populations. [ABSTRACT FROM AUTHOR]

Background: Enterocytozoon bieneusi is a microsporidian, commonly found in animals, including humans, in various countries. However, there is scant information about this microorganism in Australasia. In the present study, we conducted the first molecular epidemiological investigation of E. bieneusi in three species of marsupials (Macropus giganteus, Vombatus ursinus and Wallabia bicolor) living in the catchment regions which supply the city of Melbourne with drinking water. Methods: Genomic DNAs were extracted from 1365 individual faecal deposits from these marsupials, including common wombat (n = 315), eastern grey kangaroo (n = 647) and swamp wallaby (n = 403) from 11 catchment areas, and then individually tested using a nested PCR-based sequencing approach employing the internal transcribed spacer (ITS) and small subunit (SSU) of nuclear ribosomal DNA as genetic markers. Results: Enterocytozoon bieneusi was detected in 19 of the 1365 faecal samples (1.39%) from wombat (n = 1), kangaroos (n = 13) and wallabies (n = 5). The analysis of ITS sequence data revealed a known (designated NCF2) and four new (MWC_m1 to MWC_m4) genotypes of E. bieneusi. Phylogenetic analysis of ITS sequence data sets showed that MWC_m1 (from wombat) clustered with NCF2, whereas genotypes MWC_m2 (kangaroo and wallaby), MWC_m3 (wallaby) and MWC_m4 (kangaroo) formed a new, divergent clade. Phylogenetic analysis of SSU sequence data revealed that genotypes MWC_m3 and MWC_m4 formed a clade that was distinct from E. bieneusi. The genetic distinctiveness of these two genotypes suggests that they represent a new species of Enterocytozoon. Conclusions: Further investigations of Enterocytozoon spp. from macropods and other animals will assist in clarifying the taxonomy and epidemiology of these species in Australia and elsewhere, and in assessing the public health risk of enterocytozoonosis. [ABSTRACT FROM AUTHOR]

Camera traps are frequently used in wildlife research and may be a useful tool for monitoring behavioural patterns. The suitability of camera traps to monitor behaviour depends on the size, locomotion, and behaviour of the species being investigated. The suitability of cameras for documenting the behaviour of eastern grey kangaroos was assessed here by comparing activity patterns collected using cameras to published activity patterns for the species. The activity patterns calculated from camera trap data were largely consistent with data from previous studies, although nocturnal activity appeared to be under-represented. Observations of unusual fighting behaviour illustrates the potential for camera traps to enable capture of novel observations. Kangaroo behaviour appeared to be influenced by the presence of cameras; however, no kangaroos retreated from cameras. Data suggested that kangaroos became habituated to cameras after eight months. The findings of this study suggest that camera traps are suitable for assessing the diurnal activity of eastern grey kangaroos and are useful tools for documenting their behaviour. [ABSTRACT FROM AUTHOR]

To treat dental disorders and estimate age, it is important that veterinarians understand teeth eruption sequence for the animal in question. Few dental images of the eastern grey kangaroo have been published. In the present study, radiographic imagings of 29 kangaroos, ranging in age from 12 months to 10 years 9 months, was used to surveil the replacement of premolars and the eruption of molars. These images revealed eruption patterns in five stages, while the second and third deciduous premolars were shed non-systematically. Furthermore, the third premolars and fourth molars erupted in the mandible earlier than in the maxilla, which may contribute to the frequency of mandibular dental disorders. [ABSTRACT FROM AUTHOR]

ABSTRACT Predator‐odor‐based repellents have benefits as humane, non‐lethal management tools that may reduce the need for lethal control in some areas. Macropods (such as kangaroos and wallabies) are iconic Australian native marsupials; however, some are considered important rangeland pests, and their presence in the urban and peri‐urban environment often results in conflict. The management of these macropods is a contentious and volatile issue. We evaluated lion (Panthera leo), Sumatran tiger (P. tigris sumatrae), and dingo (Canis lupus dingo) fecal odors as short‐term odor‐based repellents for wild eastern grey kangaroos (Macropus giganteus) and red‐necked wallabies (M. rufogriseus). These odors were used to ‘protect' highly palatable food sources; with any food not consumed (residue) collected and weighed each day. Trials were conducted at Long Grass Nature Reserve in Queensland, Australia from 9–29 January 2009. Both eastern grey kangaroos and red‐necked wallabies relocated a minimum of 100 m away from the food station treated with lion odors on the first day of the trial. As a result of this spatial shift, more food was consumed at the control food stations than at any food station treated with predator odors (regardless of predator). In particular, eastern grey kangaroos never fed from a single predator‐odor food station. An increase in vigilance behaviors was observed for both macropod species, and red‐necked wallabies were more likely to exhibit vigilance behaviors than feeding behaviors at predator odor food stations. There was no difference in food residue between any predator odors and these food stations were only visited on the first day of the study. Use of predator fecal odors may repel macropods from highly palatable food sources, and predator fecal odors also may be useful for macropod relocation. © 2014 The Wildlife Society.

Most urban mammals are small. However, one of the largest marsupials, the Eastern Grey Kangaroo Macropus giganteus, occurs in some urban areas. In 2007, we embarked on a longitudinal study of this species in the seaside town of Anglesea in southern Victoria, Australia. We have captured and tagged 360 individuals to date, fitting each adult with a collar displaying its name. We have monitored survival, reproduction and movements by resighting, recapture and radio-tracking, augmented by citizen science reports of collared individuals. Kangaroos occurred throughout the town, but the golf course formed the nucleus of this urban population. The course supported a high density of kangaroos (2–5/ha), and approximately half of them were tagged. Total counts of kangaroos on the golf course were highest in summer, at the peak of the mating season, and lowest in winter, when many males but not females left the course. Almost all tagged adult females were sedentary, using only part of the golf course and adjacent native vegetation and residential blocks. In contrast, during the non-mating season (autumn and winter), many tagged adult males ranged widely across the town in a mix of native vegetation remnants, recreation reserves, vacant blocks, commercial properties and residential gardens. Annual fecundity of tagged females was generally high (≥70%), but survival of tagged juveniles was low (54%). We could not determine the cause of death of most juveniles. Vehicles were the major (47%) cause of mortality of tagged adults. Road-kills were concentrated (74%) in autumn and winter, and were heavily male biased: half of all tagged males died on roads compared with only 20% of tagged females. We predict that this novel and potent mortality factor will have profound, long-term impacts on the demography and behavior of the urban kangaroo population at Anglesea.

Drones are often considered an unobtrusive method of monitoring terrestrial wildlife; however research into whether drones disturb wildlife is in its early stages. This research investigated the potential impacts of drone monitoring on a large terrestrial mammal, the eastern grey kangaroo (Macropus giganteus), in urban and peri-urban environments. We assessed the response of kangaroos to drone monitoring by analysing kangaroo behaviour prior to and during drone deployments using a linear modelling approach. We also explored factors that influenced kangaroo responses including drone altitude, site characteristics and kangaroo population dynamics and demographics. We showed that drones elicit a vigilance response, but that kangaroos rarely fled from the drone. However, kangaroos were most likely to flee from a drone flown at an altitude of 30 m. This study suggests that drone altitude is a key consideration for minimising disturbance of large terrestrial mammals and that drone flights at an altitude of 60–100 m above ground level will minimise behavioural impacts. It also highlights the need for more research to assess the level of intrusion and other impacts that drone surveys have on the behaviour of wildlife and the accuracy of the data produced.

Objective: To develop a technique for permanent sterilisation of female eastern grey kangaroos (Macropus giganteus) and red kangaroos (M. rufus) as part of a large‐scale macropod management program on an enclosed 1545‐ha site in western Sydney. Methods: Free‐ranging female kangaroos (n = 1409: 1285 eastern grey kangaroos, 124 red kangaroos) were anaesthetised via remote anaesthetic drug delivery of tiletamine/zolazepam, medetomidine and acepromazine prior to inhalational anaesthesia using isoflurane–oxygen. A laparoscopic ovariectomy technique was developed using standard laparoscopic equipment to effect permanent sterilisation of the kangaroos. The technique described was also adapted for use on immature animals weighing as little as 1 kg. No direct post‐surgical care was provided once the animals had recovered from the anaesthetic. Results: The procedure was simple to perform and had a very high success rate, with an overall project mortality rate of 2.13% (n = 30). Seven kangaroos (0.05% of all operated kangaroos) were euthanased as a direct result of the surgical procedure. Surgical complications were rare but included inadvertent gastrointestinal tract puncture with the trocar, intraoperative haemorrhage and subcutaneous emphysema leading to pouch eversion following surgery. Conclusion: The procedure described is a rapid and effective method of permanent fertility control in macropods and carries a low mortality rate. [ABSTRACT FROM AUTHOR]

Human population growth and the resultant expansion of urban landscapes are drivers of biodiversity loss globally. Impacts of urbanisation on wildlife are not well understood, although the importance of preserving biodiversity in urban areas is widely recognised. The eastern grey kangaroo (Macropus giganteus), a common species of large macropod, can be found in high densities in many urban landscapes across Australia. South East Queensland is a subtropical region of Australia that has experienced high rates of urban expansion. Human population growth in the region has resulted in widespread changes to the landscape and much of the eastern grey kangaroo’s natural habitat has been modified. Declines in kangaroo populations have been anecdotally reported; however, the impact of urbanisation on kangaroo populations has not been quantified. This study used a modelling approach, collecting data from the community, and private and government organisations to: (1) map the current distribution of eastern grey kangaroos; (2) quantify trends in kangaroo abundance; and (3) identify anthropogenic drivers of changes in kangaroo abundance in the region. Of the kangaroo populations identified, 42% were reported to have undergone an overall decline in abundance since 2000. Higher human population growth rate and smaller area remaining under natural land use were predictors of kangaroo population declines. Further kangaroo declines can be anticipated in the region, particularly in areas with projected human population growth rates over 80% for the next decade. This study emphasises the importance of integrated urban development over large spatial extents to mitigate impacts of urbanisation on terrestrial mammals. [ABSTRACT FROM AUTHOR]

When resources are limited, organisms face allocation conflicts. Indeterminate growth creates a persistent conflict with reproduction, as growth may enhance future reproduction, but diverts resources from current reproduction. Little is known about allocation trade-offs in mammals with indeterminate growth. We studied growth and reproduction in adult female eastern grey kangaroos ( Macropus giganteus), an iteroparous mammal with indeterminate growth. Allocation trajectories varied with age and size: for 4-year-old females, fecundity increased from 30 to 82% from shortest to average-sized individuals. Older females had high fecundity regardless of size. The smallest females grew 30% more annually than average-sized females, but females that reached average size at an older age had lower growth rates. Environmental conditions affected allocation to size and reproduction. Rainy springs increased fecundity from 61 to 84% for females that had previously reproduced, but rainy winters reduced leg growth. Females in better relative condition grew 40% more than average, whereas most young of females below average relative condition failed to survive to 10 months of age. These results highlight an age-specific trade-off between growth and reproduction. Tall young females benefit from a smaller trade-off between somatic growth and early fecundity than shorter females of the same age, but older females appear to favor reproduction over growth regardless of size. Our study highlights how individual heterogeneity determines trade-offs between life-history components. We speculate that cohort effects affect age-specific reproductive success in this long-lived mammal. [ABSTRACT FROM AUTHOR]

Seasonal variation in food resources and predation risk imposes major constraints on herbivores, which must adjust their behaviour to maximize their energy intake and survival. In seasonally driven landscapes, it is not yet clear what the primary drivers are that shape seasonal variation in vigilance and feeding rates. These rates have been shown to vary in relation to various environmental, social and individual factors, but many of these factors also vary through the year, due to variation in food supply. We studied wild female eastern grey kangaroos, Macropus giganteus , under low predation risk over a year to investigate whether vigilance and feeding rates varied seasonally and whether this variation was mainly driven by food quantity or quality, group size or individuals' reproductive states. Both vigilance and feeding rates varied seasonally, as did food quantity and quality and group size. Vigilance, including antipredator (head orientation away from the group) and exclusive (i.e. vigilance without chewing) vigilance, decreased and feeding rate increased with increasing group size. However, because group size increased with food quality and quantity, food resources emerged as the primary driver of variation in behavioural strategies. These results suggest that the observed effects of group size on the trade-off between food acquisition and safety are in fact corollaries of the seasonal variation in food supply in our study system, in which the risk of predation on adults is low, and hence are by-products of the foraging choices made by kangaroos in response to the dynamics of the quantity and quality of food. [ABSTRACT FROM AUTHOR]

Macropods are susceptible to capture myopathy. A post mortem examination, and haematological and blood chemistry analysis was conducted on a male eastern grey kangaroo (Macropus giganteus) believed to have capture myopathy. Changes in blood chemistry and necrosis of muscle tissue are the most prevalent sign of myopathy in eastern grey kangaroos. [ABSTRACT FROM AUTHOR]

Poxviruses have previously been detected in macropods with cutaneous papillomatous lesions, however to date, no comprehensive analysis of a poxvirus from kangaroos has been performed. Here we report the genome sequences of a western grey kangaroo poxvirus (WKPV) and an eastern grey kangaroo poxvirus (EKPV), named for the host species from which they were isolated, western grey ( Macropus fuliginosus ) and eastern grey ( Macropus giganteus ) kangaroos. Poxvirus DNA from WKPV and EKPV was isolated and entire coding genome regions determined through Roche GS Junior and Illumina Miseq sequencing, respectively. Viral genomes were assembled using MIRA and SPAdes, and annotations performed using tools available from the Viral Bioinformatics Resource Centre. Histopathology and transmission electron microscopy analysis was also performed on WKPV and its associated lesions. The WKPV and EKPV genomes show 96% identity (nucleotide) to each other and phylogenetic analysis places them on a distinct branch between the established Molluscipoxvirus and Avipoxvirus genera. WKPV and EKPV are 170 kbp and 167 kbp long, containing 165 and 162 putative genes, respectively. Together, their genomes encode up to 47 novel unique hypothetical proteins, and possess virulence proteins including a major histocompatibility complex class II inhibitor, a semaphorin-like protein, a serpin, a 3-β-hydroxysteroid dehydrogenase/δ 5 → 4 isomerase, and a CD200-like protein. These viruses also encode a large putative protein (WKPV-WA-039 and EKPV-SC-038) with a C-terminal domain that is structurally similar to the C-terminal domain of a cullin, suggestive of a role in the control of host ubiquitination. The relationship of these viruses to members of the Molluscipoxvirus and Avipoxvirus genera is discussed in terms of sequence similarity, gene content and nucleotide composition. A novel genus within subfamily Chordopoxvirinae is proposed to accommodate these two poxvirus species from kangaroos; we suggest the name, Thylacopoxvirus (thylaco-: [Gr.] thylakos meaning sac or pouch). [ABSTRACT FROM AUTHOR]

The critically endangered box-gum grassy woodlands of south-east Australia face numerous threats including the failure of woody plant regeneration caused by over-browsing. In the Australian Capital Territory, over-browsing of tree and shrub saplings is likely caused by dense populations of Eastern Grey Kangaroo ( Macropus giganteus) found in many nature reserves free of livestock. One possible way to protect these saplings is using coarse woody debris ( CWD) as a browsing deterrent. We tested this idea by planting palatable Red Stemmed Wattle ( Acacia rubida) saplings among manually applied CWD, among naturally fallen CWD, and in the open, in five woodland reserves. We recorded the proportion of saplings browsed, the number of weeks to first browsing and the browsing severity (sapling height lost). Applied CWD protected saplings from being browsed only at relatively low-to-moderate kangaroo browsing pressure (as measured by faecal pellet counts). At relatively high browsing pressure, the probability of a sapling being browsed among applied CWD was 100%, similar to the probability in the open treatment (no CWD). Natural CWD, in contrast, provided some protection even at high browsing pressures. Time to browsing was most affected by browsing pressure, although CWD cover also had an influence. Browsing severity was similar between the three treatments and was only affected by browsing pressure. These results indicate that without protection, palatable woody plant saplings have a high chance of being browsed by kangaroos in woodland reserves, and therefore, some protection is needed for successful regeneration. The CWD being applied to reserves has a limited capacity to protect regenerating saplings. If more protection is wanted a CWD structure more resembling natural fallen timber should be used. This could be done by artificially placing branches around plantings. However, the most important action to facilitate regeneration is to manage kangaroo populations to reduce overall browsing pressure. [ABSTRACT FROM AUTHOR]

Habitat use is the most common dimension along which sympatric species partition resources to reduce competition. We conducted faecal pellet counts at Wilsons Promontory National Park, Victoria, to examine habitat use by an assemblage of mammalian herbivores with disparate evolutionary histories and varying body size: introduced European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus), and native eastern grey kangaroo (Macropus giganteus),swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus). Overlap in habitat use was low between four pairs of species, suggesting spatial partitioning of resources to reduce the potential for interspecific competition. More generally, however, overlap in habitat use was high, particularly between native and introduced grazers. These results indicate the potential for competition if resources were limiting and suggest that assemblages of species with independent evolutionary histories have inherently less resource partitioning to facilitate coexistence than assemblages of species with common evolutionary histories. Despite evidence of high overlap in habitat use between native and introduced species at a broad scale, and variation in the competitive ability of species, coexistence was likely facilitated by niche complementarity, including temporal and fine-scale partitioning of spatial resources. There was no relationship between body size and the diversity of habitats used. In contemporary assemblages of native and introduced species, evolutionary history is likely to have a strong influence on resource partitioning. [ABSTRACT FROM AUTHOR]

Question Community invasion and dominance by exotic species can be abetted by disturbance and elevated nutrient levels. However, impacts of exotics on native species are often manifest through competition, suggesting disturbance or nutrient management could benefit native species. I therefore asked: does nutrient reduction through carbon addition, or disturbance to reduce biomass, contribute to restoration by increasing occurrence and richness of native plant species? Location SE Australia. Methods Using a field experiment spanning 4 yrs, this study assessed the potential for carbon addition, three types of disturbance (burn, crop, slash) and their interaction with native herbivore grazing to reduce exotic, and increase native, plant species in a critically endangered grassy woodland in SE Australia. Results Adding carbon reduced occurrence of one native and three exotic species, while increasing one exotic and one native species. The value of adding carbon for restoration was therefore ambiguous. Fencing to exclude the high-density kangaroo population had temporary beneficial effects, suggesting that grazing reduced the number of native and exotic plant species by up to 56% and 21%, respectively. Species richness declined by year 3 in fenced areas, likely through competitive exclusion. Burn, slash and crop treatments also provided disturbance that maintained species richness and occurrence of many species, both native and exotic. Most grazing interactions reflected the benefit of alternative disturbance in the absence of grazing. However, there was also evidence that two species declined when crop and grazing acted in combination. Conclusions Very high grazing by native herbivores reduced plant species richness in this study. However, grazing or other forms of disturbance appeared critical for preventing a small number of exotic species from driving down occurrence and richness of many other native and exotic plant species. Although increased exotic species richness is undesirable, disturbance led to a better outcome for conservation than the low-disturbance alternatives. [ABSTRACT FROM AUTHOR]

Sociability, how individuals interact with conspecifics, is considered to be a key axis of animal personality. Consistent differences between individuals in measures of sociability have been demonstrated in some taxa, yet individuals also exhibit plasticity in their sociability across differing ecological conditions, particularly in gregarious species that do not occur in stable cohesive groups. Although repeatability and plasticity of measures of sociability are both important for understanding animal personality they have rarely been studied concurrently. Between and even within species, multiple behaviours have been considered to represent sociability, but there is still little understanding of the degree to which different measures of sociability reflect distinct traits. In this study, our first aim was to determine the repeatability of four different measures, representing two broad aspects of individual females' sociability, in a wild population of eastern grey kangaroos, Macropus giganteus . Our second aim was to investigate how shorter-term environmental conditions and individuals' states related to plasticity in these measures. Using data collected each month over a 5-year period on over 100 adult females, we analysed factors contributing to variation in individuals' grouping patterns (to reflect general gregariousness) and in the number of different conspecifics with which individuals associated (their ‘choosiness’ of social partners). Rainfall, body condition and reproductive state were all related to females' mean group sizes, and females with older dependent young foraged further from their neighbours. Females were more selective about group members when there was more food, and when they were in poor or excellent body condition. Although social preferences exist among females in this population, and females' measures of sociability are repeatable and differ between individuals over the long term, these current findings suggest that the influences of individuals' states and environmental conditions contribute to variation in females' patterns of sociability over shorter periods. [ABSTRACT FROM AUTHOR]

Animals exhibit a range of dispersal strategies that impact on the organisation of individuals and can be influenced by both the environment and population demography. We examined the fine-scale spatial genetic structure and patterns of relatedness in 139 adult eastern grey kangaroos (Macropus giganteus) to test predictions of male-biased dispersal and female philopatry in comparison with previous studies in different environments in the species' distributions. We found evidence of limited differences between the sexes, with little spatial genetic structure in both males and females. The levels of relatedness among females in close proximity were not indicative of close relatives (e.g. mother-daughter) and there was no evidence of matrilineal structure. Among males, there was little evidence of genetic structure. Although our results are, in general, consistent with those of previous studies, we found study-specific differences in the extent of genetic structure that appear to be related to differences in environmental and demographic conditions across the distribution. This highlights the need for additional research focussing on populations from a range of environmental conditions. [ABSTRACT FROM AUTHOR]

Dispersal reduces the likelihood of inbreeding and maintains gene flow among populations. Many polygynous mammals exhibit male-biased dispersal with female philopatry. Previous observational studies of eastern grey kangaroos (Macropus giganteus) suggested female philopatry while genetic studies showed weak structuring. We tested for sex-biased dispersal using two Queensland populations of kangaroos: one in Sundown National Park and the second at Elanda Point, Australia. Samples from 25 females and 23 males were collected from Sundown National Park, and analysed for partial mtDNA control region sequences (n = 47) and genotypes based on 12 microsatellite loci (n = 41). Samples from 18 males and 22 females from Elanda Point were genotyped at 8 loci and a subset sequenced for mtDNA (n = 19). Analyses showed higher mtDNA haplotype and nucleotide diversity in males than females within both populations, genetic relatedness based on microsatellite data was significantly higher among females, and microsatellite allelic richness was higher in males, suggesting that females are more likely to be philopatric and males more likely to disperse. These findings reinforce the value of including multiple types of genetic markers in dispersal analyses as mtDNA results showed higher male diversity (suggesting male dispersal) but males also contributed microsatellite alleles to the local population, masking differentiation between the sexes and confounding analyses. [ABSTRACT FROM AUTHOR]

Collisions of vehicles with wildlife kill and injure animals and are also a risk to vehicle occupants, but preventing these collisions is challenging. Surveys to identify problem areas are expensive and logistically difficult. Computer modeling has identified correlates of collisions, yet these can be difficult for managers to interpret in a way that will help them reduce collision risk. We introduce a novel method to predict collision risk by modeling hazard (presence and movement of vehicles) and exposure (animal presence) across geographic space. To estimate the hazard, we predict relative traffic volume and speed along road segments across southeastern Australia using regression models based on human demographic variables. We model exposure by predicting suitable habitat for our case study species (Eastern Grey Kangaroo Macropus giganteus) based on existing fauna survey records and geographic and climatic variables. Records of reported kangaroo-vehicle collisions are used to investigate how these factors collectively contribute to collision risk. The species occurrence (exposure) model generated plausible predictions across the study area, reducing the null deviance by 30.4%. The vehicle (hazard) models explained 54.7% variance in the traffic volume data and 58.7% in the traffic speed data. Using these as predictors of collision risk explained 23.7% of the deviance in incidence of collisions. Discrimination ability of the model was good when predicting to an independent dataset. The research demonstrates that collision risks can be modeled across geographic space with a conceptual analytical framework using existing sources of data, reducing the need for expensive or time-consuming field data collection. The framework is novel because it disentangles natural and anthropogenic effects on the likelihood of wildlife-vehicle collisions by representing hazard and exposure with separate, tunable submodels. [ABSTRACT FROM AUTHOR]

Lancefield Swamp, south-eastern Australia, was one of the earliest sites to provoke interest in Pleistocene faunal extinctions in Sahul (Pleistocene Australia-New Guinea). The systematic investigation of the deposit in the early 1970s identified megafaunal remains dominated by the 100–200 kg kangaroo Macropus giganteus titan . Associated radiocarbon ages indicated that the species was extant until c.30,000 BP, suggesting significant overlap with human settlement of Sahul. This evidence was inconsistent with contemporary models of rapid human-driven extinctions. Instead, researchers inferred ecological tethering of fauna at Lancefield Swamp due to intense drought precipitated localised mass deaths, consistent with Late Pleistocene climatic variability. Later investigations in another part of the swamp, the Mayne Site, remote to the initial investigations, concluded that mass flow disturbed this area, and Electron Spin Resonance (ESR) analyses on megafauna teeth returned wide-ranging ages. To clarify site formation processes and dating of Lancefield Swamp, we excavated new test-pits next to previous trenches in the Classic and Mayne Sites. We compared absolute chronologies for sediments and teeth, sedimentology, palaeo-topography, taphonomy, and macropod age at death across the swamp. Luminescence dating of sediments and ESR analysis of teeth returned ages between c.80,000 and 45,000 years ago. We found no archaeological remains in the bone beds, and evidence of carnivore activity and fluvial action, in the form of reactivated spring flow. The latter disturbed limited parts of the site and substantial areas of the bone beds remained intact. The faunal assemblage is dominated by megafaunal adult Macropus , consistent with mass die-offs due to severe drought. Such droughts appear to have recurred over millennia during the climatic variability of Marine Isotope Stages 4 and 3. These events began tens of millennia before the first appearance of Aboriginal people in Sahul and only the very youngest fossil deposits could be coeval with the earliest human arrivals. Therefore, anthropogenic causes cannot be implicated in most if not all of mass deaths at the site. Climatic and environmental changes were the main factors in site formation and megafauna deaths at Lancefield Swamp. [ABSTRACT FROM AUTHOR]

Atmospheric fluorides (gaseous and particulate) are deposited on, and absorbed by, vegetation. Ingested fluoride accumulates in calcified tissues of vertebrates, and if it is excessive, it may lead to dental and skeletal fluorosis. The prevalence, form and severity of the effects vary greatly between species. Foraging strategy can be an important determinant of fluoride exposure in herbivores, because foliar fluoride concentrations vary between plant species, for example, according to vertical and lateral position in the vegetation. We combined microhistological analysis of diet and analysis of foliar fluoride levels to examine interspecific variation in dietary fluoride exposure of macropodid marsupials (swamp wallaby Wallabia bicolor, red-necked wallaby Notamacropus rufogriseus and eastern grey kangaroo Macropus giganteus), in the buffer zone of an aluminium smelter in Victoria, Australia. Dietary niche differentiation between species was evident. The swamp wallaby and the red-necked wallaby were browsers or mixed feeders, depending on the classification system used. The eastern grey kangaroo was a grazer, consuming almost entirely grasses. However, foliar fluoride did not vary significantly between the main plant groups consumed. Our results indicate that interspecific variation in diet at this site is unlikely to explain variation in fluoride exposure. [ABSTRACT FROM AUTHOR]

Trace element profiling in the incrementally formed dentine of mammalian teeth can be applied to reconstruct temporal variation of incorporation of these elements into the tissue. Using an electron microprobe, this study analysed fluoride distribution in dentine of first and third mandibular molars of free-ranging eastern grey kangaroos inhabiting a high-fluoride area, to assess temporal variation in fluoride uptake of the animals. Fluoride content in the early-formed dentine of first molars was significantly lower than in the late-formed dentine of these teeth, and was also lower than in both, the early and the late-formed dentine of third molars. As early dentine formation in M 1 takes place prior to weaning, this finding indicates a lower dentinal fluoride uptake during the pre-weaning compared to the post-weaning period. This is hypothetically attributed to the action of a partial barrier to fluoride transfer from blood to milk in lactating females and a low bioavailability of fluoride ingested together with milk. Another factor contributing to lower plasma fluoride levels in juveniles compared to adults is the rapid clearance of fluoride from blood plasma in the former due to their intense skeletal growth. The combined action of these mechanisms is considered to explain why in kangaroos from high-fluoride areas, the (early-formed) first molars are not affected by dental fluorosis while the (later-formed) third and fourth molars regularly exhibit marked to severe fluorotic lesions. [ABSTRACT FROM AUTHOR]

We surveyed eastern grey kangaroos at four locations at the Northern Beaches region of Coffs Harbour, New South Wales, to estimate densities in this growing peri-urban region. This region is considered a regional hotspot for human–kangaroo conflict, with numerous kangaroo-related incidents in recent years. Direct counts of kangaroos were undertaken every two months during 2016. Kangaroo densities varied between sites, ranging from 0.2 individuals ha[sup –1] to 4.9 individuals ha[sup –1]. Because no estimates of population density exist for the Northern Beaches, our results assisted the development of a regional kangaroo management plan, and contribute to a broader understanding of eastern grey kangaroo densities in peri-urban areas. [ABSTRACT FROM AUTHOR]

Social relationships established early in life can have effects on social structure and influence individual fitness. Eastern grey kangaroos, Macropus giganteus , nurse their young for at least 18 months, allowing for a strong bond to develop between mothers and young. Because most female kangaroos are philopatric, the mother-offspring relationship established during lactation could persist into adulthood, resulting in clusters of female kin. Strong social bonds, however, are based on affiliative behaviours and frequent interactions. In particular, one might not expect strong bonds among related individuals unless there are advantages to interacting with relatives compared to associating with unrelated conspecifics. We examined development of the mother-offspring relationship in eastern grey kangaroos from permanent emergence from the pouch to the time of weaning. We studied a high-density population at Wilsons Promontory National Park, Victoria, Australia. There were few differences in the behaviour of sons and daughters towards mothers. However, daughters foraged slightly closer than sons to their mothers and daughters were weaned approximately 2 months later than sons if the mother did not have a surviving large pouch young. Mothers associated more closely with their daughters than their sons when offspring were aged 10–29 months but neither sex associated closely with their mothers beyond 33 months of age. Mothers never intervened to defend their young from aggressive individuals and it was the offspring that maintained spatial proximity to their mothers. Kangaroo mothers had few interactions with their juvenile offspring other than nursing. Females may be philopatric and settle near close kin as adults but kangaroos appear to have few of those early affiliative interactions necessary for social bonds to develop. [ABSTRACT FROM AUTHOR]

Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface) enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species. [ABSTRACT FROM AUTHOR]

Large mammalian herbivores are commonly infected with gastrointestinal helminths. Heavily parasitised hosts are likely to have increased nutritional requirements and would be predicted to increase their food intake to compensate for costs of being parasitised, but experimental tests of the impacts of these parasites on the foraging efficiency of hosts are lacking, particularly in free-ranging wildlife. We conducted a field experiment on a population of free-ranging eastern grey kangaroos (Macropus giganteus) to test this prediction, removing nematodes from one group of adult females using an anthelmintic treatment. We then carried out observations before and following treatment to assess the influence of parasites on foraging behaviour. Contrary to our predictions, the manipulation of parasite burdens did not result in changes in any of the key foraging variables we measured. Our results suggest that despite carrying large burdens of gastrointestinal parasites, the foraging strategy of female kangaroos is likely be driven by factors unrelated to parasitism, and that kangaroos in high nutritional environments may be able acquire sufficient nutrients to offset the costs of parasitism. We conclude that the drivers of forage intake likely differ between domesticated and free-ranging herbivores, and that free-ranging hosts are likely more resilient to parasitism. [ABSTRACT FROM AUTHOR]

The accuracy of population abundance estimates of mammalian herbivores from faecal pellet counts is potentially affected by pellet decay. We collected fresh pellet groups from hog deer (Axis porcinus), European rabbit (Oryctolagus cuniculus), eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus) (n = 300 per species) at Wilsons Promontory National Park, Victoria, Australia. We deposited five pellet groups per species per month within each of five vegetation types in the park, then monitored pellet group decay over 24 months. We demonstrate that age estimation of pellet groups was inaccurate and is unlikely to improve the efficiency of pellet counts. We present habitat- and species-specific estimates of pellet and pellet group decay using two measures: decay rate (the proportion of pellets surviving per unit of time); and mean time to decay. We explain how our data can be used to optimise faecal pellet count design, and to improve the accuracy of both indices and estimates of abundance from pellet counts. The variability observed in the decay of pellet groups among vegetation types, and for species among seasons, suggests that caution should be used if applying pellet decay rates over long time-frames or to locations with differing environmental conditions. [ABSTRACT FROM AUTHOR]

Infection with the introduced trematode Fasciola hepatica was associated with anemia, mild to moderate azotemia, hypoalbuminemia, and elevated liver enzymes and creatine kinase values in two free-ranging eastern grey kangaroos ( Macropus giganteus). Both kangaroos were euthanized because of the severity of clinical signs associated with infection. Histopathologic changes included severe cholangiohepatitis, biliary hyperplasia, and fibrosis. Hepatic, splenic, and intestinal amyloidosis was present in one kangaroo and hepatic abscessation in the other; neither histologic change has been reported in macropodids with fascioliasis previously. [ABSTRACT FROM AUTHOR]

During a long-term study on the breeding ecology of a raptor guild in the Australian Southern Tablelands of the Australian Capital Territory and New South Wales, on two occasions we observed a pair of Wedge-tailed Eagles Aquila audax killing male Eastern Grey Kangaroos Macropus giganteus. We also observed two attacks on an adult female kangaroo: one inconclusive, and one that resulted in the Eagle killing a young kangaroo expelled from the female's pouch. These observations shed some light on the way that Eagles use this food resource [ABSTRACT FROM AUTHOR]

Summary Significantly elevated bone fluoride concentrations have been reported in a population of eastern grey kangaroos ( Macropus giganteus ) resident near a fluoride-emitting aluminum smelter in southeastern Australia. This paper describes the skeletal and synovial joint lesions observed post mortem in the same sample of kangaroos ( n = 76). The prevalence and severity of skeletal lesions, specifically the formation of multiple, large, smooth exostoses over the diaphysis of long bones (especially, but not exclusively, on the tibia, fibula and metatarsi), were positively associated with bone fluoride concentration. So too were lesions of degenerative joint disease, including periarticular osteophytosis, articular cartilage erosion/ulceration, synovial hyperplasia and joint capsular fibrosis. Joint lesions were most commonly seen in the knee, hock and metatarsophalangeal joints. This is the first study to describe in detail the full range of lesions induced by chronic fluorosis in a marsupial species. [ABSTRACT FROM AUTHOR]

Adoption is rare in animals and is usually attributed to kin selection. In a 6-year study of eastern grey kangaroos (Macropus giganteus), 11 of 326 juveniles were adopted. We detected eight adoptions by observing behavioural associations and nursing between marked mothers and young and three more by analysing the relatedness of mothers and young using microsatellite DNA. Four adoptions involved reciprocal switches and three were by mothers whose own pouch young were known to subsequently disappear. Adoptive mothers were not closely related to each other or to adoptees but adoptive mothers and young associated as closely as did biological pairs, as measured by half-weight indices. Switch mothers did not associate closely. Maternal age and body condition did not influence the likelihood of adoption but females were more likely to adopt in years with high densities of females with large pouch young. Adoption did not improve juvenile survival. We conclude that adoptions in this wild population were potentially costly and likely caused by misdirected care, suggesting that eastern grey kangaroos may have poorly developed mother-offspring recognition mechanisms. [ABSTRACT FROM AUTHOR]