Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide. We evaluate the success rate in obtaining GPS fixes as well as in transferring these fixes to the user and we evaluate failure rates. Average fix success and data transfer rates were high and were generally better predicted by species and unit characteristics, while environmental characteristics influenced the variability of performance. However, 48% of the unit deployments ended prematurely, half of them due to technical failure. Nonetheless, this study shows that the performance of satellite telemetry applications has shown improvements over time, and based on our findings, we provide further recommendations for both users and manufacturers.

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Declining availability of prey is potentially a major factor limiting snow leopard Panthera uncia populations in Tajikistan and neighbouring states. Conservation initiatives to develop community-based trophy hunting programmes for ibex Capra sibirica and argali Ovis ammon polii aim to provide financial incentives for communities to limit poaching of wild ungulates. Such programmes could help to reverse local declines in ibex and argali populations, and consequently snow leopard populations, while simultaneously improving the economic status of local people. However, in practice the desired effect may not materialize. To investigate the premise, we estimated the population density of the snow leopard, using a spatial capture-recapture model based on camera trapping in two study areas (each c. , km  ) in the Tajik Pamirs: a wellmanaged trophy hunting concession and an otherwise similar area where grazing and poaching are unmanaged. We used distance-truncated counts to assess relative densities of wild and domestic ungulates between sites, and faecal analyses to compare the dietary habits of snow leopards. Our data were limited in scope but suggested that the density of snow leopards and the relative density of wild and domestic ungulates may have been greater in the hunting concession, where wild ungulates accounted for a greater proportion of prey items. Our results provide preliminary evidence that trophy hunting of ungulates may be a viable tool for achieving snow leopard conservation goals; however, we conclude that further investigation is necessary to adequately address the question.