New model to track animal paths from solar geolocators

Date:December 7, 2015

Source:Kazan Federal University

The ability to track animal movements across long distances has revolutionized our understanding of animal ecology and has been helpful to conservation. Until recently, our ability to record this information was limited to larger animals that could carry satellite transmitters. However, recent technological advances have developed miniaturized devices that extend our ability to track much smaller animals, especially migratory songbirds.

Solar archival tags (henceforth called geolocators) are tracking devices deployed on animals to reconstruct their long-distance movements on the basis of locations inferred post hoc with reference to the geographical and seasonal variations in the timing and speeds of sunrise and sunset. The increased use of geolocators has created a need for analytical tools to produce accurate and objective estimates of migration routes that are explicit in their uncertainty about the position estimates.

The model developed for the analysis of geolocator data estimates tracks for animals with complex migratory behaviour by combining: a shading-insensitive, template-fit physical model, an uncorrelated random walk movement model that includes migratory and sedentary behavioural states, and spatially explicit behavioural masks.

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