Movement is the glue connecting home ranges and habitat selection
Van Moorter B., Rolandsen C. M., Basille M., Gaillard J.-M.
Animal space use has been studied by focusing either on geographic (e.g., home ranges, species’ distribution) or environmental (e.g., habitat use and selection) space. However, all patterns of space use emerge from individual movements, which are the primary means by which animals change their environment.
Individuals increase their use of a given area by adjusting two key movement components: the duration of their visit, and/or the frequency of re-visits. Thus, in spatially heterogeneous environments animals exploit known, high-quality resource areas by increasing their Residence Time (RT) in and/or decreasing their Time to Return (TtoR) to these areas. We expected that spatial variation in these two movement properties should lead to observed patterns of space use in both geographic and environmental spaces. We derived a set of 9 predictions linking spatial distribution of movement properties to emerging space use patterns. We predicted that, at a given scale, high variation in RT and TtoR among habitats leads to strong habitat selection, and that long RT and short TtoR result in a small home range size.
We tested these predictions using moose (Alces alces) GPS tracking data. We first modelled the relationship between landscape characteristics and movement properties. Then, we investigated how the spatial distribution of predicted movement properties (i.e., spatial autocorrelation, mean, and variance of RT and TtoR) influences home range size and hierarchical habitat selection.
In landscapes with high spatial autocorrelation of RT and TtoR, a high variation in both RT and TtoR occurred in home ranges. As expected, home range location was highly selective in such landscapes (i.e., 2nd-order habitat selection); RT was higher and TtoR lower within the selected home range than outside, and moose home ranges were small. Within home ranges, a higher variation in both RT and TtoR was associated to higher selectivity among habitat types (i.e., 3rd-order habitat selection).
Our findings show how patterns of geographic and environmental space use correspond to the two sides of a coin, linked by movement responses of individuals to environmental heterogeneity. By demonstrating the potential to assess the consequences of altering RT or TtoR (e.g., through human disturbance or climatic changes) on home range size and habitat selection, our work sets the basis for new theoretical and methodological advances in movement ecology.
Reference: Van Moorter B., Rolandsen C. M., Basille
M. & Gaillard J.-M. (2016) Movement is the glue connecting home
ranges and habitat selection. Journal of Animal Ecology, 85: