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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]

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.

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.

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]

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]

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.

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]

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]

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]

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]

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]

Phylogeographic studies around the world have identified refugia where fauna were able to persist during unsuitable climatic periods, particularly during times of glaciation. In Australia the effects of Pleistocene climate oscillations on rainforest taxa have been well studied but less is known about the effects on mesic-habitat fauna, such as the eastern grey kangaroo (Macropus giganteus). The eastern grey kangaroo is a large mammal that is common and widespread throughout eastern Australia, preferring dry mesic habitat, rather than rainforest. As pollen evidence suggests that the central-eastern part of Australia (southeast Queensland and northern New South Wales) experienced cycles of expansion in mesic habitat with contraction in rainforests, and vice versa during glacial and interglacial periods, respectively, we hypothesise that the distribution of the eastern grey kangaroo was affected by these climate oscillations and may have contracted to mesic habitat refugia. From 375 mitochondrial DNA control region sequences from across the distribution of eastern grey kangaroos we obtained 108 unique haplotypes. Phylogenetic analysis identified two clades in Queensland, one of which is newly identified and restricted to a small coastal region in southern Queensland north of Brisbane, known as the Sunshine Coast. The relatively limited geographic range of this genetically isolated clade suggests the possibility of a mesic habitat refugium forming during rainforest expansion during wetter climate cycles. Other potential, although less likely, reasons for the genetic isolation of the highly distinct clade include geographic barriers, separate northward expansions, and strong local adaptation. [ABSTRACT FROM AUTHOR]

The Trivers-Willard hypothesis predicts that, in polygynous and sexually dimorphic mammals, mothers able to provide a large amount of care should produce more sons. Tests of this prediction, however, have generated equivocal results, possibly because multiple factors, including environmental conditions, simultaneously influence progeny sex ratio. We tested the influence of maternal mass, condition, size, previous reproduction and age class on offspring sex ratio in two populations of eastern grey kangaroos ( Macropus giganteus). In one population, heavier and taller mothers produced more sons than did lighter mothers, but maternal condition had no effect on progeny sex ratio. Primiparous females, however, produced an even offspring sex ratio despite being smaller than multiparous females. A strong year effect on progeny sex ratio suggested a likely effect of environmental conditions. In the second population, none of the variables tested influenced progeny sex ratio. Different environmental conditions between the two populations could partly explain these results. Because maternal size and mass likely correlate with reproductive potential, we suggest that our results support the Trivers-Willard hypothesis, but other variables likely also influence progeny sex ratio. [ABSTRACT FROM AUTHOR]

Personality and behavioral syndromes are of significant interest to a wide range of biological disciplines. Recent research using network analysis techniques has revealed widespread variation among individuals in sociability, which is a major axis of personality that creates the social microenvironment in which individuals express all other behaviors. We investigated the relationship between sociability and boldness, another fundamental personality axis, using a wild population of eastern grey kangaroos (Macropus giganteus) tested in their natural environment. We studied 2 dimensions of sociability (grouping behavior and association patterns). Over 2 years we found significant within-individual consistency and interindividual variation in the foraging group sizes of 171 females. Network analysis comparisons of 103 females between the years, using HWIG (an association index that controls for gregariousness), showed that individuals were also highly consistent in their social network measures. We tested the boldness of 51 of these females 6-21 times each over 18 months, using flight initiation distance tests; individuals were also highly consistent in this measure of personality. Shy females had significantly larger mean foraging group sizes. After controlling for gregariousness and space use, shy females had fewer preferred associates than bolder females. Therefore, boldness can have an important influence on the size and composition of foraging groups and thus social networks, in wild mammals. [ABSTRACT FROM AUTHOR]

Background To date, Cryptosporidium cuniculus has been found exclusively in rabbits and humans. The present study provides the first published molecular evidence for C. cuniculus in an Australian human patient as well as a kangaroo. Findings Using PCR-based sequencing of regions in the actin, 60 kDa glycoprotein (gp60) and small subunit of ribosomal RNA (SSU) genes, we identified a new and unique C. cuniculus genotype (akin to VbA25) from a human, and C. cuniculus genotype VbA26 from an Eastern grey kangaroo (Macropus giganteus) in Australia. Conclusions The characterisation of these genotypes raises questions as to their potential to infect humans and/or other animals in Australia, given that C. cuniculus has been reported to cause cryptosporidiosis outbreaks in Europe. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

For many herbivorous mammal species across the world, geophagy, the consumption of soil, is an important method for obtaining minerals, especially sodium. However, this behavior has not been recorded in marsupials. The eastern grey kangaroo (Macropus giganteus), an intensively studied macropod species, is known to use physiological and micromorphological adaptations to conserve sodium. We present results of another adaptation, the use of natural licks, by this species and 3 other macropod species at Sundown National Park, Australia. Natural licks had significantly higher levels of sodium, magnesium, and sulfur than surrounding soils. We examined patterns of lick use by kangaroos to test 3 possible proximate causes of geophagy: whether lick use was affected by dietary mineral content, life-history stage, and thermoregulation. The number of kangaroos visiting the licks increased with temperature and mean cloud cover, varied among months, and was marginally significantly influenced by dietary mineral content. Visit durations to one lick increased with temperature and were influenced by month and life-history stage; females with high lactation demand and large males spent the most time at the lick. The proportion of time spent in geophagy when at a focal lick varied with month and reproductive state. Therefore geophagy is not restricted to eutherian mammals, and kangaroos, like many eutherian species, appear to adjust this behavior in response to their mineral demand. Geophagy in kangaroos is facultative, rather than obligative, and has not been detected in other intensively studied populations. In areas of Australia with low levels of sodium, high temperatures, and suitable lick sites, geophagy may play a key role in marsupial ecology. [ABSTRACT FROM AUTHOR]

The article offers information on a study conducted by researchers Julian Motha, Nino Ficorilli and Carol Anne Hartley from University of Melbourne and Centre for AgriBioscience, to isolate and characterize the novel herpesvirus from a free-ranging eastern grey kangaroo which displayed signs of neurologic and respiratory diseases. It discusses the sequence analysis of the virus that is related to macropodid herpesvirus 2, which is capable of infecting the kangaroos.

Abstract: Australian marsupials are unique fauna that have evolved and adapted to unique environments and thus it is likely that their detoxification systems differ considerably from those of well-studied eutherian mammals. Knowledge of these processes in marsupials is therefore vital to understanding the consequences of exposure to xenobiotics. Cytochromes P450 (CYPs) are critically important in the oxidative metabolism of a diverse array of both xenobiotics and endogenous substrates. In this study we have cloned and characterized CYP3A70, the first identified member of the CYP3A gene subfamily from Eastern gray kangaroo (Macropus giganteus). A 1665 base pair kangaroo hepatic CYP3A complete cDNA, designated CYP3A70, was cloned by reverse transcription-polymerase chain reaction approaches, which encodes a protein of 506 amino acids. The CYP3A70 cDNA shares approximately 71% nucleotide and 65% amino acid sequence homology to human CYP3A4 and displays high sequence similarity to other published mammalian CYP3As from human, monkey, cow, pig, dog, rat, rabbit, mouse, hamster, and guinea pig. Transfection of the CYP3A70 cDNAs into 293T cells resulted in stable cell lines expressing a CYP3A immuno-reactive protein that was recognized by a goat anti-human CYP3A4 polyclonal antibody. The anti-human CYP3A4 antibody also detected immunoreactive proteins in liver microsomes from all test marsupials, including the kangaroo, koala, wallaby, and wombat, with multiple CYP3A immunoreactive bands observed in kangaroo and wallaby tissues. Relatively, very low CYP catalytic activity was detected for the kangaroo CYP3A70 cDNA-expressed proteins (19.6 relative luminescent units/μg protein), which may be due to low protein expression levels. Collectively, this study provides primary molecular data regarding the Eastern kangaroo hepatic CYP3A70 gene and enables further functional analyses of CYP3A enzymes in marsupials. [Copyright &y& Elsevier]

Aggregation is thought to enhance an animal's security through effective predator detection and the dilution of risk. A decline in individual vigilance as group size increases is commonly reported in the literature and called the group size effect. However, to date, most of the research has only been directed toward examining whether this effect occurs at the population level. Few studies have explored the specific contributions of predator detection and risk dilution and the basis of individual differences in the use of vigilance tactics. We tested whether male and female (non-reproductive or with young) eastern grey kangaroos (Macropus giganteus) adopted different vigilance tactics when in mixed-sex groups and varied in their reliance on predator detection and/or risk dilution as group size changed. This species exhibits pronounced sexual dimorphism with females being much smaller than males, making them differentially vulnerable toward predators. We combined field observations with vigilance models describing the effects of detection and dilution on scanning rates as group size increased. We found that females with and without juveniles relied on predator detection and risk dilution, but the latter adjusted their vigilance to the proportion of females with juveniles within their group. Two models appeared to equally support the data for males suggesting that males, similarly to females, relied on predator detection and risk dilution but may also have adjusted their vigilance according to the proportion of mothers within their group. Differential vulnerability may cause sex differences in vigilance tactic use in this species. The presence of males within a group that do not, or only partially, contribute to predator detection and are less at risk may cause additional security costs to females. Our results call for reexamination of the classical view of the safety advantages of grouping to provide a more detailed functional interpretation of gregariousness. [ABSTRACT FROM AUTHOR]

Lactation is the most energetically expensive component of reproduction in mammals. Theory predicts that reproducing females will adjust their behaviour to compensate for increased nutritional demands. However, experimental tests are required, since comparisons of the behaviour of naturally reproducing and non-reproducing females cannot distinguish between true costs of reproduction, individual differences or seasonal variation. We experimentally manipulated reproduction in free-ranging, eastern grey kangaroos (Macropus giganteus), using a fertility control agent. Our novel field experiment revealed that females altered their behaviour in direct response to the energetic demands of reproduction: reproducing females increased bite rates, and thus food intake, when the energetic demands of lactation were highest. Reproducing females did not reduce the time spent on vigilance for predators, but increased their forage intake on faecal-contaminated pasture, thereby increasing the risk of infection by gastrointestinal parasites-a largely unrecognized potential cost of reproduction. [ABSTRACT FROM AUTHOR]

Kangaroos (Macropus spp.) are one of the most abundant native macrofauna on Australian floodplains with a positive relationship between their density and the deposition of faecal pellets that contain nutrients and carbon.We tested whether kangaroo faecal pellets are a source of nutrients and carbon during flooding in the Macquarie Marshes, an inland floodplain wetland, in south-eastern Australia.The faecal pellets of kangaroos, most likely of Red Kangaroo (M. rufus), were found on the dry floodplain adjacent to Bora Channel (-30.6433°SI-.- 147.535 I °E) at a density of 142±54 m2 (mean±SE, n3). Following artificial inundation, we monitored the release of total nitrogen (TN), total phosphorus (TP) and dissolved organic carbon (DOC) five times over a six-day period from mesocosms deployed in situ.Three mesocosms contained faecal pellets and three mesocosms contained marsh floodplain sediments (top 5 cm of sediment consisting of soils and plant material) with faecal pellets removed. The concentrations (mean±SE, n3) of TN,TP and DOC in the mesocosms containing the pellets were 0.037±0.017, 0.22±0.060 and 0.69±0.14 g m2 at day 6, while the mesocosms containing only the marsh floodplain sediments were 1.03±0.23, 0.49±0.083 and 7.27±1.02 g m2. On average, the kangaroo faecal pellets contributed -6% of TN, -31% of TP and - 8% of DOC of the total amounts respectively released from the inundated floodplain over the six-day experiment. Nutrient and carbon depositions to floodplains in the form of faecal pellets from large terrestrial animals such as kangaroos are an important process of cycling these elements in inland floodplain wetlands, especially where large populations of these animals occur. [ABSTRACT FROM AUTHOR]

1. High densities of vertebrate herbivores can be a significant barrier to ecological restoration in many parts of the world because of their impact on vegetation biomass. A common method for managing vertebrate herbivores is the use of exclosure fences, but very few studies have examined how small-scale structural refugia (e.g. logs) can mitigate grazing impacts. We examined how beetles responded to experimentally manipulated kangaroo Macropus giganteus grazing levels using both exclosure fences and addition of logs over a 16-month period. 2. We analysed beetle responses across (a) one-hectare sites, by focusing on the interaction between grazing level and log volume, and (b) microhabitats, by focusing on the interaction between grazing level and microhabitat structure (in open ground or at experimental logs). 3. At the site scale, we detected significant negative effects of grazing and positive effects of logs on beetle abundance and species richness. Beetle trophic groups responded in the same direction across grazing levels with herbivores, detritivores and predators all having higher abundance and species richness at low grazing levels. Logs applied at 20 t ha [ABSTRACT FROM AUTHOR]

Using implanted temperature loggers, we measured core body temperature in nine western grey kangaroos every 5min for 24 to 98days in spring and summer. Body temperature was highest at night and decreased rapidly early in the morning, reaching a nadir at 10:00h, after ambient temperature and solar radiation had begun to increase. On hotter days, the minimum morning body temperature was lower than on cooler days, decreasing from a mean of 36.2°C in the spring to 34.0°C in the summer. This effect correlated better with the time of the year than with proximate thermal stressors, suggesting that either season itself or some factor correlated with season, such as food availability, caused the change. Water saving has been proposed as a selective advantage of heterothermy in other large mammals, but in kangaroos the water savings would have been small and not required in a reserve with permanent standing water. We calculate that the lower core temperature could provide energy savings of nearly 7%. It is likely that the heterothermy that we observed on hot days results either from decreased energy intake during the dry season or from a seasonal pattern entrained in the kangaroos that presumably has been selected for because of decreased energy availability during the dry season [ABSTRACT FROM AUTHOR]

Group size is known to affect both the amount of time that prey animals spend in vigilance and the degree to which the vigilance of group members is synchronized. However, the variation in group-size effects reported in the literature is not yet understood. Prey animals exhibit vigilance both to protect themselves against predators and to monitor other group members, and both forms of vigilance presumably influence group-size effects on vigilance. However, our understanding of the patterns of individual investment underlying the time sharing between anti-predator and social vigilance is still limited. We studied patterns of variation in individual vigilance and the synchronization of vigilance with group size in a wild population of eastern grey kangaroos (Macropus giganteus) subject to predation, in particular focusing on peripheral females because we expected that they would exhibit both social and anti-predator vigilance. There was no global effect of group size on individual vigilance. The lack of group-size effect was the result of two compensating effects. The proportion of time individuals spent looking at other group members increased, whereas the proportion of time they spent scanning the environment decreased with group size; as a result, overall vigilance levels did not change with group size. Moreover, a degree of synchrony of vigilance occurred within groups and that degree increased with the proportion of vigilance time peripheral females spent in anti-predator vigilance. Our results highlight the crucial roles of both social and anti-predator components of vigilance in the understanding of the relationship between group size and vigilance, as well as in the synchronization of vigilance among group members. [ABSTRACT FROM AUTHOR]

Green leaves of six grass species in temperate Australia showed considerable circadian variation (especially in summer) in water content, which peaked late in the night and fell from sunrise to an afternoon minimum. In summer, water content of a set of ‘wetter’ species ( Axonopus affinis, Pennisetum clandestinum and Paspalum dilatatum) was consistently higher and varied less profoundly through the 24 h than that of a ‘drier’ set ( Imperata cylindrica, Poa labillardieri and Themeda triandra). Hour-to-hour and day-to-day variation in leaf water content of P. dilatatum in summer partly but imperfectly reflected ambient temperature. Recognizing the risks for herbivores of visiting water sources, we considered leaf water content as a source of free water for leaf-grazing herbivores, eastern grey kangaroos Macropus giganteus and common wombats Vombatus ursinus. Using known field metabolic rates, energy requirements and digestive efficiencies, we calculated these two species' free-water intakes when satisfying their energy needs with these grasses but distributing their grazing in different schedules. Both species would obtain more free water by their observed foraging schedules than by random or daytime-only schedules. We calculated that the measured grasses could satisfy the water requirements of wombats but not always those of kangaroos, who would need to drink when forage water content was less than about 70%. Water content of grass leaf could rise above and fall below this value within a day, creating some scope for kangaroos to manage their need to visit water by adjusting foraging schedules or choice of grass species. In future studies, circadian variation in leaf water content should be considered as a factor (together with their thermal physiology) driving herbivores' activity scheduling, and affecting their dietary selection. [ABSTRACT FROM AUTHOR]

Large mammalian herbivores must balance foraging efficiency with multiple constraints, including the risk of gastrointestinal parasitism. The costs imposed by gastrointestinal parasites are likely to exert selective pressure on hosts to develop aversion behaviors. Fecal aversion, or the avoidance of foraging patches contaminated by feces, is one mechanism by which herbivores can reduce their exposure to gastrointestinal parasites transmitted through the fecal contamination of foraging grounds. As feces also fertilize the surrounding pasture, herbivores may face a choice between the benefits of increased nutrient intake and an increased risk of parasitism. We investigated fecal aversion in free-ranging eastern grey kangaroos (Macropus giganteus), including the potential conflict between fecal aversion and increased nutrient intake, through a combination of field observations and a field experiment. Kangaroos exhibited fecal aversion by moving through contaminated patches as they were encountered. The experiment revealed that both sward height and fecal contamination affected the kangaroos’ choice of foraging patches: kangaroos preferred taller grass but would not accept a higher risk of parasitism for increased nutrient intake. [ABSTRACT FROM PUBLISHER]

In group-forming prey species, theory assumes that individuals within groups should scan independently of one another, with vigilance sequences being relatively unpredictable, making interscan durations highly variable. We attempted to detect any divergence from randomness in the scanning process in three mammalian prey species phylogenetically and geographically separated and exposed to different levels of predation: waterbuck, Kobus ellipsiprymnus defassa, under a high observed predation risk, eastern grey kangaroo, Macropus giganteus, still experiencing occasional predation and European roe deer, Capreolus capreolus, under a very low natural predation risk. Our results revealed that the focal interscan duration increased when the duration of the preceding interscan increased, whatever the studied species and the predation risk that its individuals experienced, and decreased with the preceding scan duration in two species under, respectively, occasional and low predation risks. The exponential distribution was the tested model that fitted the observed distributions of interscan durations least well. We discuss what can trigger non-randomness in scanning, through a non-homogenous Poisson process, at both intra-individual and inter-individual levels, particularly with regard to previous studies that have demonstrated synchronisation of vigilance in such mammals. Our results suggest the need to reconsider any assumption of randomness in scanning in the basic model predicting form and frequency of scanning behaviour by prey species. [ABSTRACT FROM AUTHOR]

The mean vigilance of animals in a group often decreases as their group size increases, yet nothing is known about whether there is individual variability in this relationship in species that change group sizes frequently, such as those that exhibit fission–fusion social systems. We investigated variability in the relationship between group size and vigilance in the eastern grey kangaroo ( Macropus giganteus) by testing whether all individuals showed decreased vigilance with increased group size, as has been commonly assumed. We carried out both behavioural observations of entire groups of kangaroos and focal observations of individually recognised wild female kangaroos. As in other studies, we found a collective group-size effect on vigilance; however, individuals varied in their vigilance patterns. The majority (57%) of the identified individual kangaroos did not show significant group-size effects for any of the recorded measures of vigilance. The females that did not show a negative group-size effect were, on average, more vigilant than those females that did show a group-size effect, but this difference was not significant. We propose that some females exhibit higher levels of social vigilance than others, and that this social vigilance increases with group size, cancelling out any group-size effect on anti-predator vigilance for those females. Our results therefore suggest that only some prey individuals may gain anti-predator benefits by reducing their time spent scanning when in larger groups. The large amount of variation that we found in the vigilance behaviour of individual kangaroos highlights the importance of collecting and analysing vigilance data at the individual level, which requires individual recognition. [ABSTRACT FROM AUTHOR]

The relevance of vigilance activity to predator detection has been demonstrated in numerous studies. However, few studies have investigated the effect of one group member being vigilant on the probability of others being vigilant in group-forming prey species. Thus, we studied vigilance activity of eastern gray kangaroos Macropus giganteus that still experience occasional predation. We video recorded the behavior of all group members simultaneously and investigated the probability of a focal group member being vigilant (or nonvigilant) in relation to other individuals vigilant and nonvigilant behaviors. Our results show that the decision of an individual to exhibit a vigilant posture depended on what it and other group members had been doing (scanning or foraging) at the preceding second and on group size. The probability of an individual being vigilant was positively affected by the proportion of companions that were vigilant at the previous second, confirming the existence in this species of a tendency for synchronization of individual vigilance. Group size affected individuals vigilance in 3 ways. First, individuals were more likely to be vigilant if the proportion of their group mates that was vigilant was high, and this was strengthened with increasing group size. Second, the effect of the individuals own vigilance state (vigilant or not) at the previous second also increased with group size. Third, the probability of an individual being vigilant decreased with group size. These findings increase our understanding of the much-studied relationship between vigilance and group size. [ABSTRACT FROM AUTHOR]

The future impacts of climate change are predicted to significantly affect the survival of many species. Recent studies indicate that even species that are relatively mobile and/or have large geographic ranges may be at risk of range contractions or extinction. An ecologically and evolutionary significant group of mammals that has been largely overlooked in this research is Australia's large marsupial herbivores, the macropodids (kangaroos). The aims of our investigation were to define and compare the climatic conditions that influence the current distributions of four sympatric large macropodids in northern Australia (Macropus antilopinus, Macropus robustus, Macropus giganteus, and Macropus rufus) and to predict the potential future impact of climate change on these species. Our results suggest that contemporary distributions of these large macropodids are associated with well-defined climatic gradients (tropical and temperate conditions) and that climatic seasonality is also important. Bioclimatic modeling predicted an average reduction in northern Australian macropodid distributions of 48 %± 16.4% in response to increases of 2.0°C. At this temperature, the distribution of M. antilopinus was reduced by 89% ± 0.4%. We predict that increases of 6.0°C may cause severe range reductions for all four macropodids (96% ± 2.1%) in northern Australia, and this range reduction may result in the extinction of M. antilopinus. [ABSTRACT FROM AUTHOR]

1. Viggers & Hearn (2005) examined the encroachment of native herbivores on to farmland. They presented kangaroo home range estimates and pasture biomass data for three sites in south-eastern Australia, then made broad management recommendations regarding the preservation of remnant habitat. 2. While Viggers & Hearn identified potentially important patterns, we believe that their data were neither sufficient nor appropriate to reveal the processes that underlie these patterns. 3. Specifically, their study was unreplicated at the land-use level, used inappropriate density estimates for their study populations, failed to measure resources adequately, used flawed methods of home range analysis, and demonstrated limited understanding of key concepts and of their study species and thus could not draw valid conclusions. 4. Synthesis and applications. In view of these fundamental problems, we recommend that decisions on the management of kangaroos and remnant vegetation not be based on the work reported by Viggers & Hearn. [ABSTRACT FROM AUTHOR]

Models of kangaroo populations have primarily focused on the prediction of population growth and distribution in relation to environmental variation at broad geographic scales. Current understanding of small-scale patterns in distribution, habitat breadth, and niche occupation is less complete. A powerful model of dispersion is ideal free distribution (IFD) theory. In plant-herbivore grazing systems, the most appropriate IFD models are those that allow for the incorporation of a standing crop of resources. Using eastern grey kangaroos (Macropus giganteus). we test the predictions of a previously described standing-crop IFD model where the number of consumers on a patch is proportional to the resource input rate, the standing crop of resources on all patches at equilibrium are equal (in the absence of interference), and the resource mortality rate is directly equivalent to the resource input rate, and is independent of the resource density (in the absence of interference). We make these comparisons at both the habitat and patch scale. At the habitat scale, we observed significant departures from these predictions that are consistent with the commonly reported occurrence of undermatching, whereas at the patch scale. little concordance with the predictions was observed. These results suggest that eastern grey kangaroos select for resources at the habitat scale but not at the level of the patch. [ABSTRACT FROM AUTHOR]

Genetic information has played an important role in the development of management units by focusing attention on the evolutionary properties and genetics of populations. Wildlife authorities cannot hope to manage species effectively without knowledge of geographical boundaries and demic structure. The present investigation provides an analysis of mitochondiral DNA and microsatellite data, which is used to infer both historical and contemporary patterns of population structuring and dispersal in the eastern grey kangaroo (Macropus giganteus) in Australia. The average level of genetic variation across sample locations was one of the highest observed for marsupials (h = 0.95, H[SUBE] = 0.82). Contrary to ecological studies, both genic and genotypic analyses reveal weak genetic structure of populations, where high levels of dispersal may be inferred up to 230 km. The movement of individuals was predominantly male-biased (average N[SUBe]m = 22.61, average N[SUBf]m = 2.73). However, neither sex showed significant isolation by distance. On a continental scale, there was strong genetic differentiation and phylogeographic distinction between southern (TAS, VIC and NSW) and northern (QLD) populations, indicating a current and/or historical restriction of gene flow. In addition, it is evident that northern populations are historically more recent, and were derived from a small number of southern founders. Phylogenetic comparisons between M. g. giganteus and M. g. tasmaniensis indicated that the current taxonomic status of these subspecies should be revised as there was a lack of genetic differentiation between the populations sampled. [ABSTRACT FROM AUTHOR]

Summary In southeastern Australia ecological burning is frequently used to maintain a number of plant and animal populations. However, many of these prescribed fires are small, and may focus intense grazing activity on new regrowth. At Reef Hills Regional Park, Victoria shrub species have senesced, presumably due to the absence of fire. Ecological burning may be necessary to promote regeneration, however, the population density of the Eastern Grey Kangaroo (Macropus giganteus ) is high (approx 38 per km2), and grazing pressure presents a significant risk to postfire vegetation recovery. An assessment of grazing patterns and their effects on postfire recovery was carried out at Reef Hills Regional Park through grazing exclusion plots. Preferential grazing by Eastern Grey Kangaroos occurred on small burnt plots compared to adjacent unburnt areas as determined by faecal pellet counts. On burnt areas, there was a significant reduction in shrub diversity on grazed plots compared to ungrazed plots. Most observations of kangaroos were of animals grazing on farmland surrounding the Park, and it is likely that any burning might shift grazing from farmland to burnt areas when new growth occurs. This needs to be considered before any ecological burn plan is applied to manage vegetation communities, particularly if the plan requires small areas to be burnt. We recommended that a large area up to 200 ha area be burnt and monitored to determine whether burning larger areas disperses grazing pressure from macropods to a level where impacts on vegetation are reduced and localized plant extinctions do not occur. [ABSTRACT FROM AUTHOR]

For a free-ranging forager, the suitability of a patch is dependent on population density, resource supply, resource quality, and the costs of foraging or dispersal. We quantified differences among three foraging habitats and compared this variation to temporal patterns of habitat preference by free-ranging eastern grey kangaroos, Macropus giganteus. We investigated selection on a fine-grained spatial scale, and asked whether habitat preference is constrained by density-dependent mechanisms. Variation in the quantity and quality of resources among habitats was greatest during spring, when biomass and quality were highest, and differences among habitats were most pronounced. However, consistent and discernable differences among habitats were not obtained, indicating that the system fluctuated around an equilibrium state. Using isodar regressions to examine the consumer-density relationships among habitats, open-woodland habitat was favoured over the two open-forest habitats for foraging. Seasonal isodars indicated that density dependence regulated preference between the three foraging habitats during autumn, spring and summer, but not during winter, when variability in resources among habitats was lowest. [ABSTRACT FROM AUTHOR]