Revisitation analysis uncovers spatio-temporal patterns in animal movement data
3 February 2018Bracis, Chloe; Bildstein, Keith L.; Mueller, Thomas
Animals regularly return to locations such as foraging patches, nests, dens, watering holes, or movement corridors, and these revisited locations are often sites of ecological significance. Analyzing the temporal and spatial pattern of revisitation can lead to important insights into the life history and ecology of populations. We introduce the R package recurse to calculate revisitations to locations in the movement trajectory or other locations for one or multiple individuals. The package also calculates metrics such as residence time and time between visits. It can be used to quantitatively identify frequently used sites (e.g., dens, nests, foraging locations), to examine patterns of revisitation and link them with covariates such as habitat features or climatic data, and to address conservation questions of interest about specific locations. We present an example application with movement trajectory data from a Turkey Vulture (Cathartes aura) during the breeding season and demonstrate analyzing recursions, specific locations, seasonal and daily temporal patterns, and visit timing. The recurse package should be of interest both to ecologists looking to analyze their movement data and to conservationists needing site-specific information for management and conservation actions.