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Understanding wildlife-vehicle collision risk is critical to mitigating its negative impacts on wildlife conservation, human health and economy. Research often focuses on collisions between wildlife and road vehicles, but collision risk factors for other types of vehicles, less examined in the literature, may also be informative. We studied spatial and temporal variation in wildlife-train collision risk in the State of Victoria, Australia. We quantified train movements in space and time, and mapped species occurrence likelihood, across the railway network. Using spatially- and temporally-resolved collision data, we fitted a model to analyse collisions between trains and kangaroos; accounting for time of day, train frequency and speed, and kangaroo occurrence. We then predicted collision rates on the passenger railway network under three management scenarios relating to train speed and occurrence of kangaroos near the railway lines. Temporal variation in animal activity was the strongest predictor of collision risk. Train speed was the second most influential variable, followed by spatial variation in likelihood of species occurrence. Reducing speeds in areas of high predicted species occurrence and during periods of peak animal activity (early morning and evening for kangaroos) was predicted to reduce collision risk the most. Our results suggest mechanisms that might improve existing wildlife-transport collision analyses. The model can help managers decide where, when and how best to mitigate collisions between animals and transport. It can also be used to predict high-risk locations or times for (a) timetable/schedule changes (b) proposals for new routes or (c) disused routes considered for re-opening. [ABSTRACT FROM AUTHOR]

Progressive body-size dwarfing of animal populations is predicted under chronic mortality stress, such as that inflicted by human harvesting. However, empirical support for such declines in body size due to elevated mortality is lacking. In fact, the size of three macropodid species - the two grey kangaroo species, Macropus fuliginosus and M. giganteus, and the Red-necked Wallaby, M. rufogriseus - appears to have increased since European settlement in Australia, despite these species being subjected to size-selective harvesting over this period. To test whether this unexpected trend also characterises other species, we sought evidence of humaninduced body-size changes in the two most widely distributed kangaroo species, the Euro Macropus robustus and Red Kangaroo M. rufus, from the late 19th Century onwards. Spatial autoregressive models controlling for age, sex and island effects were first used to identify environmental predictors of body size and to evaluate multi-causal explanations for spatial body-size patterns. Primary productivity emerged as the key driver of body size in both species, while heat conservation was supported as a further mechanism explaining the large body size of M. robustus in cold climatic regions. After controlling for these environmental factors, we find that the size of M. rufus has been stable over time and limited support for a small increase in the size of M. robustus. Hence, there is no empirical evidence that contemporary size-selective harvesting has reduced body size in these species. Rather, the latter result supports the possibility that pasture improvement and/or dingo control (and associated reduction in predation pressure) facilitated body-size increases following European settlement in Australia. [ABSTRACT FROM AUTHOR]

Culling kangaroos, Australia's most abundant marsupial, is a controversial practice in the Australian Capital Territory (ACT). The ACT government introduced a kangaroo management plan in response to the growing kangaroo population causing damage in grassland ecosystems. Although some groups (e.g., local government, some researchers) support implementation of this plan, critics claim it is inhumane and lacks concrete evidence. To examine media portrayal of this debate, this study conducted a content analysis of newspaper coverage between 2006 and 2016. Although ACT newspapers were impartial in their presentation of the debate, sources that previous studies found were typically considered trustworthy to speak on the scientific validity of the program were found to have conflicting messages and be less represented in the media. Thus, future research should explore if the messenger is more important than the message in determining influences on public perceptions about the use of lethal control. [ABSTRACT FROM AUTHOR]

There are environmental advantages to the commercial harvesting of kangaroo over domestic stock. Kangaroo, however, are able to jump fences and move among properties with ease. Consequently, questions of ownership and the equitable distribution of profits arise. We model a cooperative where two neighboring ranches experience rainfall equally but asynchronously each year. A kangaroo population roams freely among the properties to graze. Through harvesting, the population can be regarded as constant. In a cooperative, the location at which harvesting occurs is irrelevant but significant differences in the consumption of resources will affect the profit sharing arrangements between the property owners. Results indicate that the resources consumed on each property with the same total primary production may differ depending on the timing of rainfall. On average, however, the population consumption on each property is independent of the intra-annual differences in rainfall distribution and hence primary production. Recommendations for Resource Managers The mobile nature of kangaroos should not be an impediment to their sustainable utilization for commercial purposes., Spatial differences in the timing of the first rainfall in a season will affect the time a roving kangaroo population spends at each location. Hence in a cooperative these differences will affect the contribution of each ranch to the total secondary production of the cooperative., Over the long term if there is no mean difference in the start of the rainfall season between two ranches then the annual fluctuations in this difference will not affect the contribution of each ranch to the cooperative enterprise., For the purpose of distributing profits, a cooperative should focus attention on any differences in the longer-term primary production of each property. [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]

The article reports that over-grazing by herbivores (especially Kangaroos) reducing vegetation cover and diversity, increasing soil degradation, and driving biodiversity loss. Topics include detection of the vulnerable striped legless lizard declines dramatically with high kangaroo densities; factors for high density comprising due to absence of predators and ready access to permanent water in farm dams, and management of grazing required to prevent biodiversity loss and ecosystem degradation.

The pathogenesis of synucleinopathies, common neuropathological lesions normally associated with some human neurodegenerative disorders such as Parkinson's disease, dementia with Lewy bodies and multiple system atrophy, remains poorly understood. In animals, ingestion of the tryptamine-alkaloid-rich phalaris pastures plants causes a disorder called Phalaris staggers, a neurological syndrome reported in kangaroos. The aim of the study was to characterise the clinical and neuropathological changes associated with spontaneous cases of Phalaris staggers in kangaroos. Gross, histological, ultrastructural and Immunohistochemical studies were performed to demonstrate neuronal accumulation of neuromelanin and aggregated α-synuclein. ELISA and mass spectrometry were used to detect serum-borne α-synuclein and tryptamine alkaloids respectively. We report that neurons in the central and enteric nervous systems of affected kangaroos display extensive accumulation of neuromelanin in the perikaryon without affecting neuronal morphology. Ultrastructural studies confirmed the typical structure of neuromelanin. While we demonstrated strong staining of α-synuclein, restricted to neurons, intracytoplasmic Lewy bodies inclusions were not observed. α-synuclein aggregates levels were shown to be lower in sera of the affected kangaroos compared to unaffected herd mate kangaroos. Finally, mass spectrometry failed to detect the alkaloid toxins in the sera derived from the affected kangaroos. Our preliminary findings warrant further investigation of Phalaris staggers in kangaroos, potentially a valuable large animal model for environmentally-acquired toxic synucleinopathy. [ABSTRACT FROM AUTHOR]