Navigating the flow: individual and continuum models for homing in flowing environments

Area of Science:

• Ecology
• Biophysics
• Mathematical Biology

Background:

• Animal navigation occurs in dynamic aquatic and airborne environments with complex flow patterns.
• Individual-based models (IBMs) simulate species movement in flows but are computationally intensive.
• Traditional continuous models offer broader insights but lack individual-level detail.

Purpose of the Study:

• To formulate an individual-based model for navigation in flowing fields.
• To derive a corresponding macroscopic, continuous model using scaling.
• To apply the model to diverse movement strategies and 'homing' behaviors.

Main Methods:

• Development of a novel individual-based model for navigation in fluid dynamics.
• Application of mathematical scaling techniques to transition from individual-based to continuous models.
• Testing the model with simulated drifters and cue-responding navigators.

Main Results:

• The derived continuous model effectively captures navigation dynamics across different movement types.
• The model successfully simulates 'homing' behaviors, demonstrating its practical utility.
• Specific application to the navigation of green turtles (Chelonia mydas) to Ascension Island.

Conclusions:

• The new modeling approach integrates the strengths of individual-based and continuous methods.
• This framework provides a computationally tractable yet detailed tool for studying animal dispersal and navigation.
• The model offers valuable insights into marine species' responses to oceanic currents and environmental cues.