Smoothing Splines of Apex Predator Movement: Functional modeling
strategies for exploring animal behavior and social interactions
Abstract
The collection of animal position data via GPS tracking devices has
increased in quality and usage in recent years. Animal position and
movement, although measured discretely, follows the same principles of
kinematic motion, and as such, the process is inherently continuous and
differentiable. I demonstrate the functionality and visual elegance of
smoothing spline models. I discuss the challenges and benefits of
implementing such an approach, and I provide an analysis of movement and
social interaction of seven jaguars inhabiting the Taiamã Ecological
Station, Pantanal, Brazil. In the analysis, I derive measures for
pairwise distance, cooccurence and spatiotemporal associaton between
jaguars, borrowing ideas from density estimation and information theory.
These measures are feasible as a result of spline model estimation, and
they provide a critical tool for a deeper investigation of cooccurence
duration, frequency, and localized spatio-temporal relationships between
animals.