Bioinspired magnetoreception and navigation in nonorthogonal environments using magnetic signatures

Abstract

Diverse taxa use Earth's magnetic field in conjunction with other sensory modalities to accomplish navigation tasks ranging from local homing to long-distance migration across continents and ocean basins. However, despite extensive research, the mechanisms that underlie animal magnetoreception are not clearly understood, and how animals use Earth's magnetic field to navigate is an active area of investigation. Concurrently, Earth's magnetic field offers a signal that engineered systems can leverage for navigation in environments where man-made systems such as GPS are unavailable or unreliable. Using a proxy for Earth's magnetic field, and inspired by migratory animal behavior, this work implements a behavioral strategy that uses combinations of magnetic field inclination and intensity as rare or unique signatures that mark specific locations. Specifically, to increase the realism of previous work, in this study, a simulated agent uses a magnetic signatures based strategy to migrate in magnetic environments where lines of constant inclination and intensity are not necessarily orthogonal. The results further support existing notions that some animals may use combinations of magnetic properties as navigational markers, and provide insights into features and constraints that could enable navigational success or failure in either a biological or engineered system.

Gauge-and-compass migration: inherited magnetic headings and signposts can adapt to changing geomagnetic landscapes

“…As an alternative to a clock-and-compass migratory orientation program, it has been proposed that naïve migrants might be able to perform navigation by following gradients in the geomagnetic field (4,28). However, this would result either tend to produce nearly N-S routes following large-scale inclination or intensity gradients, or else involve interpolation between often nearly-parallel inclination and intensity gradients (27,86).…”

“…For example, laboratory experiments with naïve oceanic migrants such as hatchling turtles and salmon fry, geomagnetic-induced shifts in headings seem to induce headings which would facilitate travel through supportive current systems (4), and there is evidence that naïve migratory bird orientation sometimes co-varies with the geomagnetic field (25,26). However, the geomagnetic component or combination of components which naïve migrants are able to perceive and respond to remains unclear, and the efficacy of geomagnetic-signposted migration, while theoretically feasible (27,28), has not been assessed for actual migration systems. In particular, we currently lack any information about the necessary precision in inheritance of migratory traits, such as headings or geomagnetic signposts, to track geomagnetic drift, which can occur rapidly in some areas such as currently near the geomagnetic North Pole (29,30).…”

Magnetic maps in animal navigation

“…13 ). Simulations of navigation based on magnetic signatures have provided evidence that such a strategy is plausible (Taylor 2018 ; Taylor and Corbin 2019 ). An interesting speculation is that the repeated circling of penguins, sea turtles, whales and other ocean migrants observed at some locations (Narazaki et al 2021 ) facilitates learning the magnetic field of that area, so that animals can remember the field and use it as a navigational marker on subsequent trips.…”

Long-distance transequatorial navigation using sequential measurements of magnetic inclination angle

“…Some works have focused on theoretical moment-to-moment (i.e. sequential) modelling approaches that would account for detailed decision-making along a trajectory [31][32][33][34][35]. Others have examined the ecological impacts of high-level navigation behaviours, such as actively swimming at specific locations or waypoints along a migratory route versus passively drifting the rest of the time [20,29,30,36,37].…”