Animal navigation: A noisy magnetic compass?
Johnsen, Sönke ; Lohmann, Ken and Warrant, Eric LU
(2020)
In Journal of Experimental Biology
223(18).
- Abstract
- Diverse organisms use Earth’s magnetic field as a cue in
orientation and navigation. Nevertheless, eliciting magnetic
orientation responses reliably, either in laboratory or natural
settings, is often difficult. Many species appear to preferentially
exploit non-magnetic cues if they are available, suggesting that the
magnetic sense often serves as a redundant or ‘backup’ source of
information. This raises an interesting paradox: Earth’s magnetic field
appears to be more pervasive and reliable than almost any other
navigational cue. Why then do animals not rely almost exclusively on
the geomagnetic field, while ignoring or downplaying other cues?
Here, we explore a possible explanation: that the... (More) - Diverse organisms use Earth’s magnetic field as a cue in
orientation and navigation. Nevertheless, eliciting magnetic
orientation responses reliably, either in laboratory or natural
settings, is often difficult. Many species appear to preferentially
exploit non-magnetic cues if they are available, suggesting that the
magnetic sense often serves as a redundant or ‘backup’ source of
information. This raises an interesting paradox: Earth’s magnetic field
appears to be more pervasive and reliable than almost any other
navigational cue. Why then do animals not rely almost exclusively on
the geomagnetic field, while ignoring or downplaying other cues?
Here, we explore a possible explanation: that the magnetic sense of
animals is ‘noisy’, in that the magnetic signal is small relative to
thermal and receptor noise. Magnetic receptors are thus unable to
instantaneously acquire magnetic information that is highly precise or
accurate. We speculate that extensive time-averaging and/or other
higher-order neural processing of magnetic information is required,
rendering the magnetic sense inefficient relative to alternative cues
that can be detected faster and with less effort. This interpretation is
consistent with experimental results suggesting a long time course for
magnetic compass and map responses in some animals. Despite
possible limitations, magnetoreception may be maintained by natural
selection because the geomagnetic field is sometimes the only
source of directional and/or positional information available. (Less) - Abstract (Swedish)
- Diverse organisms use Earth’s magnetic field as a cue in orientation and navigation. Nevertheless, eliciting magnetic orientation responses reliably, either in laboratory or natural settings, is often difficult. Many species appear to preferentially exploit non-magnetic cues if they are available, suggesting that the magnetic sense often serves as a redundant or ‘backup’ source of information. This raises an interesting paradox: Earth’s magnetic field appears to be more pervasive and reliable than almost any other navigational cue. Why then do animals not rely almost exclusively on the geomagnetic field, while ignoring or downplaying other cues? Here, we explore a possible explanation: that the magnetic sense of animals is ‘noisy’, in that... (More)
- Diverse organisms use Earth’s magnetic field as a cue in orientation and navigation. Nevertheless, eliciting magnetic orientation responses reliably, either in laboratory or natural settings, is often difficult. Many species appear to preferentially exploit non-magnetic cues if they are available, suggesting that the magnetic sense often serves as a redundant or ‘backup’ source of information. This raises an interesting paradox: Earth’s magnetic field appears to be more pervasive and reliable than almost any other navigational cue. Why then do animals not rely almost exclusively on the geomagnetic field, while ignoring or downplaying other cues? Here, we explore a possible explanation: that the magnetic sense of animals is ‘noisy’, in that the magnetic signal is small relative to thermal and receptor noise. Magnetic receptors are thus unable to instantaneously acquire magnetic information that is highly precise or accurate. We speculate that extensive time-averaging and/or other higher-order neural processing of magnetic information is required, rendering the magnetic sense inefficient relative to alternative cues that can be detected faster and with less effort. This interpretation is consistent with experimental results suggesting a long time course for magnetic compass and map responses in some animals. Despite possible limitations, magnetoreception may be maintained by natural selection because the geomagnetic field is sometimes the only source of directional and/or positional information available. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/42255b7f-7a45-44cf-8902-d7d15c48682c
- author
- Johnsen, Sönke
; Lohmann, Ken
and Warrant, Eric
LU
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Magnetoreception, Orientation, Migration, Signal-to-noise
- in
- Journal of Experimental Biology
- volume
- 223
- issue
- 18
- article number
- jeb164921
- pages
- 7 pages
- publisher
- The Company of Biologists Ltd
- ISSN
- 1477-9145
- project
- Hunting for the elusive "sixth" sense: navigation and magnetic sensation in a nocturnal migratory moth (MagneticMoth)
- language
- English
- LU publication?
- yes
- additional info
- This work was funded by the European Union (EU) and the Horizon 2020 program: European Research Council (ERC) Advanced Grant MagneticMoth (grant no. 741298)
- id
- 42255b7f-7a45-44cf-8902-d7d15c48682c
- date added to LUP
- 2022-06-01 08:44:20
- date last changed
- 2023-05-10 14:00:57
@article{42255b7f-7a45-44cf-8902-d7d15c48682c,
abstract = {{Diverse organisms use Earth’s magnetic field as a cue in<br/>orientation and navigation. Nevertheless, eliciting magnetic<br/>orientation responses reliably, either in laboratory or natural<br/>settings, is often difficult. Many species appear to preferentially<br/>exploit non-magnetic cues if they are available, suggesting that the<br/>magnetic sense often serves as a redundant or ‘backup’ source of<br/>information. This raises an interesting paradox: Earth’s magnetic field<br/>appears to be more pervasive and reliable than almost any other<br/>navigational cue. Why then do animals not rely almost exclusively on<br/>the geomagnetic field, while ignoring or downplaying other cues?<br/>Here, we explore a possible explanation: that the magnetic sense of<br/>animals is ‘noisy’, in that the magnetic signal is small relative to<br/>thermal and receptor noise. Magnetic receptors are thus unable to<br/>instantaneously acquire magnetic information that is highly precise or<br/>accurate. We speculate that extensive time-averaging and/or other<br/>higher-order neural processing of magnetic information is required,<br/>rendering the magnetic sense inefficient relative to alternative cues<br/>that can be detected faster and with less effort. This interpretation is<br/>consistent with experimental results suggesting a long time course for<br/>magnetic compass and map responses in some animals. Despite<br/>possible limitations, magnetoreception may be maintained by natural<br/>selection because the geomagnetic field is sometimes the only<br/>source of directional and/or positional information available.}},
author = {{Johnsen, Sönke and Lohmann, Ken and Warrant, Eric}},
issn = {{1477-9145}},
keywords = {{Magnetoreception; Orientation; Migration; Signal-to-noise}},
language = {{eng}},
number = {{18}},
publisher = {{The Company of Biologists Ltd}},
series = {{Journal of Experimental Biology}},
title = {{Animal navigation: A noisy magnetic compass?}},
url = {{https://lup.lub.lu.se/search/files/119436178/JEXBIO164921_R1.pdf}},
volume = {{223}},
year = {{2020}},
}