Strong Anomalous Diffusion for Free-ranging Birds
- đ¤ Speaker: Ohad Vilk (Hebrew University of Jerusalem)
- đ Date & Time: Thursday 11 September 2025, 15:50 - 15:55
- đ Venue: External
Abstract
Diffusion and anomalous diffusion are widely observed and used to study movement across organisms, resulting in extensive use of the mean and mean-squared displacement (MSD). However, these measures—corresponding to specific displacement moments—do not capture the full complexity of movement behavior. Using high-resolution data from over 70 million localizations of young and adult free-ranging Barn Owls (\textit{Tyto alba}), we reveal strong anomalous diffusion as nonlinear growth of displacement moments. The moment spectrum function $\lambda_t(q)$—defined by $\left<|\bm{x}(t)|q\right> \sim t{\lambda_t(q)}$—displays piecewise linearity in $q$, with a critical moment marking the crossover between scaling regimes. This highlights the need of a broad spectrum of displacement moments to characterize movement, which we link to age-specific ecological drivers. Furthermore, a characteristic timescale of five minutes marks an unexpected transition from a convex to a concave $\lambda_t(q)$. Using two stochastic models—a bounded Lévy walk and a multi-mode behavioral model—we account for the observed phenomena, showing good agreement with data, relating age-specific behavioral states to environmentally confined movement, and demonstrating how Lévy walk-like patterns can arise from underlying behavioral structure. Finally, we discuss the ecological significance of our results, arguing that strong anomalous diffusion may be widespread in animal movement.
Series This talk is part of the Isaac Newton Institute Seminar Series series.
Included in Lists
- All CMS events
- bld31
- dh539
- External
- Featured lists
- INI info aggregator
- Isaac Newton Institute Seminar Series
- School of Physical Sciences
Note: Ex-directory lists are not shown.
![[Talks.cam]](/static/images/talkslogosmall.gif)

Ohad Vilk (Hebrew University of Jerusalem)
Thursday 11 September 2025, 15:50-15:55