Uncovering how animals use combinations of magnetic field properties to navigate: a computational approach

Pizzuti, Susan; Bernish, Margaret; Harvey, Andrew S.; Tourangeau, Luc; Shriver, Cassandra; Kehl, Catherine; Taylor, Brian K.

doi:10.1007/s00359-021-01523-0

Cited by 6 publications

(5 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For actual migration systems, this has only been assessed for migration based on correlated random walks—per definition less directed than compass courses—with supplemental navigational abilities based on geomagnetic information [ 38 ]. While gradient-based navigation using innate or early-learned information offers the possibility to correct for imprecision or displacement [ 88 ], e.g., by currents, it could also produce inefficient migrations when gradients in field components are closely aligned [ 9 , 29 , 38 , 90 ]. Our results suggest that constant-heading migration modulated by magnetic signposts could be sufficiently robust to variable and changing geomagnetic fields, at least given suitable compass precision and intrinsic variability in inherited headings.…”

Section: Discussionmentioning

confidence: 99%

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

2023

View full text Add to dashboard Cite

Background For many migratory species, inexperienced (naïve) individuals reach remote non-breeding areas independently using one or more inherited compass headings and, potentially, magnetic signposts to gauge where to switch between compass headings. Inherited magnetic-based migration has not yet been assessed as a population-level process, particularly across strong geomagnetic gradients or where long-term geomagnetic shifts (hereafter, secular variation) could create mismatches with magnetic headings. Therefore, it remains unclear whether inherited magnetic headings and signposts could potentially adapt to secular variation under natural selection. Methods To address these unknowns, we modelled migratory orientation programs using an evolutionary algorithm incorporating global geomagnetic data (1900–2023). Modelled population mixing incorporated both natal dispersal and trans-generational inheritance of magnetic headings and signposts, including intrinsic (stochastic) variability in inheritance. Using the model, we assessed robustness of trans-hemispheric migration of a migratory songbird whose Nearctic breeding grounds have undergone rapid secular variation (mean 34° clockwise drift in declination, 1900–2023), and which travels across strong geomagnetic gradients via Europe to Africa. Results Model-evolved magnetic-signposted migration was overall successful throughout the 124-year period, with 60–90% mean successful arrival across a broad range in plausible precision in compass headings and gauging signposts. Signposted migration reduced trans-Atlantic flight distances and was up to twice as successful compared with non-signposted migration. Magnetic headings shifted plastically in response to the secular variation (mean 16°–17° among orientation programs), whereas signpost latitudes were more constrained (3°–5° mean shifts). This plasticity required intrinsic variability in inheritance (model-evolved σ ≈ 2.6° standard error), preventing clockwise secular drift from causing unsustainable open-ocean flights. Conclusions Our study supports the potential long-term viability of inherited magnetic migratory headings and signposts, and illustrates more generally how inherited migratory orientation programs can both mediate and constrain evolution of routes, in response to global environmental change.

show abstract

Section: Discussionmentioning

confidence: 99%

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

2023

View full text Add to dashboard Cite

show abstract

“…Alternatively, more advanced naïve migrant abilities beyond compass-based movement have been proposed to explain enhanced orientation correction following displacement 4 , or control of naïve trans-oceanic migration routes 72 . Naïve migrants are accordingly proposed to gauge gradients in both geomagnetic intensity and inclination along their inaugural route, to either adjust (inherited) compass headings as a corrective measure 4 , 69 , or else perform gradient-based navigation towards (inherited) geomagnetic goal signatures 73 , 74 . Apart from perceptive and cognitive feasibility, the efficacy of the former ability and the efficiency of the latter remains to be established, in particular given the overall N–S gradients in both geomagnetic intensity and inclination 74 , 75 .…”

Section: Discussionmentioning

confidence: 99%

Predicting performance of naïve migratory animals, from many wrongs to self-correction

2022

View full text Add to dashboard Cite

Migratory orientation of many animals is inheritable, enabling inexperienced (naïve) individuals to migrate independently using a geomagnetic or celestial compass. It remains unresolved how naïve migrants reliably reach remote destinations, sometimes correcting for orientation error or displacement. To assess naïve migratory performance (successful arrival), we simulate and assess proposed compass courses for diverse airborne migratory populations, accounting for spherical-geometry effects, compass precision, cue transfers (e.g., sun to star compass), and geomagnetic variability. We formulate how time-compensated sun-compass headings partially self-correct, according to how inner-clocks are updated. For the longest-distance migrations simulated, time-compensated sun-compass courses are most robust to error, and most closely resemble known routes. For shorter-distance nocturnal migrations, geomagnetic or star-compass courses are most robust, due to not requiring nightly cue-transfers. Our predictive study provides a basis for assessment of compass-based naïve migration and mechanisms of self-correction, and supports twilight sun-compass orientation being key to many long-distance inaugural migrations.

show abstract

“…For actual migration systems, this has only been assessed for migration based on correlated random walks – per definition less directed than compass courses – with supplemental navigational abilities based on geomagnetic information (32). While an innate or early-learned navigational ability offers the possibility to correct for imprecision or displacement, e.g., by currents, it could also produce inefficient migrations whenever gradients in field components are closely aligned (29,90). Our results suggest that constant-heading migration modulated by magnetic signposts could be sufficiently robust to variable and changing geomagnetic fields, at least given suitable intrinsic variability in inherited headings.…”

Section: Discussionmentioning

confidence: 99%

“…Experimental evidence suggests that naïve oceanic (9) and avian (10,28) migrants indeed can use geomagnetic information to mediate orientation shifts, but is inconclusive regarding which magnetic components are used and the extent to which updated headings are either extrapolated in situ or predetermined, i.e., inherited. If the former, naïve migrants have been proposed to reach inherited magnetic “signature” locations by following perceived or extrapolated gradients in bi-coordinate geomagnetic components, e.g., inclination and intensity, (9,29). Alternatively, naïve migrants could potentially mediate switches ( Zugknicks ) between a fixed sequence of inherited headings upon passing inherited magnetic signposts, e.g., a threshold value of inclination or intensity (6,9,10).…”

Section: Introductionmentioning

confidence: 99%

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

McLaren

Schmaljohann²,

Blasius³

2022

Preprint

View full text Add to dashboard Cite

For many migratory species, inexperienced (naïve) individuals reach remote non-breeding areas independently using inherited headings and geomagnetic compass cues. naïve migrants are also proposed to detour regions with unfavourable habitat or currents using inherited geomagnetic signposts to trigger changes in migratory headings. However, it remains unexplored whether migration based on inherited geomagnetic traits (headings and/or signposts) is viable at population levels, particularly in regions with strong spatial geomagnetic gradients or long-term geomagnetic changes. To address this unknown, we developed a migration model incorporating spatiotemporal geomagnetic data (1900-2015) and an evolutionary algorithm, accounting for trans-generational changes in inherited geomagnetic traits through population mixing and natal dispersal. Using this model, we assessed songbird migration from a highly unstable geomagnetic region (East-arctic North America and Greenland) via Europe to Africa. Model-evolved geomagnetic-based migration was (i) consistently successful over the 116-year period, (ii) up to twice as successful when geomagnetic-signposted compared with non-signposted migration, and (iii) consistent with records of detoured trans-Atlantic songbird migration in the wild. Our study supports the long-term viability of geomagnetic migratory headings, the benefit of inherited geomagnetic signposts, and illustrates how migratory orientation programs can mediate evolution of routes, in response to global environmental change.

show abstract

Uncovering how animals use combinations of magnetic field properties to navigate: a computational approach

Cited by 6 publications

References 40 publications

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

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

Predicting performance of naïve migratory animals, from many wrongs to self-correction

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

Contact Info

Product

Resources

About