Infrasound as a Cue for Seabird Navigation

Samantha C Patrick,Thomas A Clay,E Emiel Van Loon,Oliver Padget,Olivier F C Den Ouden,Mark K Prior,Mathieu Basille,Richard A Phillips,Lucía Martina Martín López,Christine Köppl,E Pascal Malkemper,Simon Benhamou,Rocío Joo,Jeffrey N Zeyl,Annette L Fayet,Läslo Evers ,Jakob Christensen‐Dalsgaard ,Pieter Smets ,Jelle Assink ,Susana Clusella‐Trullas

doi:10.3389/fevo.2021.740027

Abstract

Seabirds are amongst the most mobile of all animal species and spend large amounts of their lives at sea. They cross vast areas of ocean that appear superficially featureless, and our understanding of the mechanisms that they use for navigation remains incomplete, especially in terms of available cues. In particular, several large-scale navigational tasks, such as homing across thousands of kilometers to breeding sites, are not fully explained by visual, olfactory or magnetic stimuli. Low-frequency inaudible sound, i.e., infrasound, is ubiquitous in the marine environment. The spatio-temporal consistency of some components of the infrasonic wavefield, and the sensitivity of certain bird species to infrasonic stimuli, suggests that infrasound may provide additional cues for seabirds to navigate, but this remains untested. Here, we propose a framework to explore the importance of infrasound for navigation. We present key concepts regarding the physics of infrasound and review the physiological mechanisms through which infrasound may be detected and used. Next, we propose three hypotheses detailing how seabirds could use information provided by different infrasound sources for navigation as an acoustic beacon, landmark, or gradient. Finally, we reflect on strengths and limitations of our proposed hypotheses, and discuss several directions for future work. In particular, we suggest that hypotheses may be best tested by combining conceptual models of navigation with empirical data on seabird movements and in-situ infrasound measurements.

Highlights

Birds conduct some of the longest migrations in the animal kingdom (e.g., Croxall et al, 2005; Egevang et al, 2010), and are considered model organisms for the study of animal navigation (Wallraff, 2005; Guilford et al, 2011)
We provide an overview of infrasound source types in Supplementary Material Appendix 1
A beacon is a detectable feature with a characteristic, but not necessarily unique, signature that stands at a target location and provides information linked to its direction, assuming the source is stable over time, like a light bulb for a moth (Figure 4A)

Summary

Introduction

Birds conduct some of the longest migrations in the animal kingdom (e.g., Croxall et al, 2005; Egevang et al, 2010), and are considered model organisms for the study of animal navigation (Wallraff, 2005; Guilford et al, 2011). Island infrasound array generally greater than 50 dB relative to 20 μPa sound level pressure (SPL), and increase toward lower frequencies, this varies across species (see Figure 1 in Zeyl et al, 2020).

Results

Conclusion