Tracking animals to their death


  • Graeme C. Hays

    Corresponding author
    1. School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Warrnambool, Vic, Australia
    2. Department of Biosciences, Swansea University, Swansea, UK
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Satellite tracking is a tool for not only recording the long-distance movements of a range of species, but also for revealing animal mortality. (a) An osprey equipped with a satellite tag to record its migration from Europe to Sub-Saharan Africa. Photo: Raymond Klaassen. (b) A dead osprey. Satellite tracking can identify when and where animals die and also sometimes the cause of death. Photo: Ewan Weston. (c) This technique can also be used with other taxa. A loggerhead turtle satellite-tracked to its death in Greece. Propeller marks indicated that this individual had been hit by a boat before washing ashore dead. Photo: Gail Schofield. In Focus: Klaassen, R.H.G., Hake, M., Strandberg, R., Koks, B.J., Trierweiler, C., Exo, K.-M., Bairlein, F. & Alerstam, T. (2014) When and where does mortality occur in migratory birds? Direct evidence from long-term satellite tracking of two raptors. Journal of Animal Ecology, 83, 176–184.Migration may be a high-risk period. In a study involving three species of raptor migrating from Europe to Sub-Saharan Africa, Klaassen et al. (2014) satellite-tracked 51 out of 69 birds to their deaths and showed that rate of mortality during migration was 6x that during stationary phases when birds were on their winter and summer grounds. Travel across the Sahara was particularly risky. Satellite tracking has also been used to infer mortality in other taxa (e.g. sea turtles) and may allow high-risk hotspots to be identified for wide-ranging species.