Estimating behavioral parameters in animal movement models using a state‐augmented particle filter

Data on fine‐scale animal movement are being collected worldwide, with the number of species being tagged and the resolution of data rapidly increasing. In this study, a general methodology is proposed to understand the patterns in these high‐resolution movement time series that relate to marine animal behavior. The approach is illustrated with dive data from a northern fur seal ( Callorhinus ursinus ) tagged on the Pribilof Islands, Alaska, USA. We apply a state‐space model composed of a movement model and corresponding high‐resolution vertical movement data. The central goal is to estimate parameters of this movement model, particularly their variation on appropriate time scales, thereby providing a direct link to behavior. A particle filter with state augmentation is used to jointly estimate the movement parameters and the state. A multiple iterated filter using overlapping data segments is implemented to match the parameter time scale with the behavioral inference. The time variation in the auto‐covariance function facilitates identification of a movement model, allows separation of observation and process noise, and provides for validation of results. The analysis yields fitted parameters that show distinct time‐evolving changes in fur seal behavior over time, matching well what is observed in the original data set.