Orientation in the wandering albatross: interfering with magnetic perception does not affect orientation performance (original) (raw)
Related papers
Journal of The Royal Society Interface, 2013
The mechanisms by which migratory birds achieve their often spectacular navigational performance are still largely unclear, but perception of cues from the Earth's magnetic field is thought to play a role. Birds that possess migratory experience can use map-based navigation, which may involve a receptor that uses ferrimagnetic material for detecting gradients in the magnetic field. Such a mechanism can be experimentally disrupted by applying a strong magnetic pulse that re-magnetizes ferrimagnetic materials. In captivity, this treatment indeed affected bearings of adult but not of naive juvenile birds. However, field studies, which expose birds to various navigational cues, yielded mixed results. Supportive studies were difficult to interpret because they were conducted in spring when all age groups navigate back to breeding areas. The present study, therefore, applied a magnetic pulse treatment in autumn to naturally migrating, radio-tagged European robins. We found that, although overall bearings were seasonally correct, orientation of adult but not juvenile robins was compromised by a pulse. Pulsed adults that departed within 10 days of treatment failed to show significant orientation and deviated more from mean migration direction than adult controls and juveniles. Thus, our data give field-based support for a possible ferrimagnetic map-sense during bird migration.
Magnetic orientation and magnetoreception in birds and other animals
Journal of Comparative Physiology A, 2005
Animals use the geomagnetic field in many ways: the magnetic vector provides a compass; magnetic intensity and/or inclination play a role as a component of the navigational 'map', and magnetic conditions of certain regions act as 'sign posts' or triggers, eliciting specific responses. A magnetic compass is widespread among animals, magnetic navigation is indicated e.g. in birds, marine turtles and spiny lobsters and the use of magnetic 'sign posts' has been described for birds and marine turtles. For magnetoreception, two hypotheses are currently discussed, one proposing a chemical compass based on a radical pair mechanism, the other postulating processes involving magnetite particles. The available evidence suggests that birds use both mechanisms, with the radical pair mechanism in the right eye providing directional information and a magnetitebased mechanism in the upper beak providing information on position as component of the 'map'. Behavioral data from other animals indicate a lightdependent compass probably based on a radical pair mechanism in amphibians and a possibly magnetitebased mechanism in mammals. Histological and electrophysiological data suggest a magnetite-based mechanism in the nasal cavities of salmonid fish. Little is known about the parts of the brain where the respective information is processed.
No evidence for the use of magnetic declination for migratory navigation in two songbird species
PLOS ONE, 2020
Determining the East-West position was a classical problem in human sea navigation until accurate clocks were manufactured and sailors were able to measure the difference between local time and a fixed reference to determine longitude. Experienced night-migratory songbirds can correct for East-West physical and virtual magnetic displacements to unknown locations. Migratory birds do not appear to possess a time-different clock sense; therefore, they must solve the longitude problem in a different way. We showed earlier that experienced adult (but not juvenile) Eurasian reed warblers (Acrocephalus scirpaceus) can use magnetic declination (the difference in direction between geographic and magnetic North) to solve this problem when they were virtually displaced from Rybachy on the eastern Baltic coast to Scotland. In this study, we aimed to test how general this effect was. Adult and juvenile European robins (Erithacus rubecula) and adult garden warblers (Sylvia borin) under the same experimental conditions did not respond to this virtual magnetic displacement, suggesting significant variation in how navigational maps are organised in different songbird migrants.
Evidence that pigeons orient to geomagnetic intensity during homing
Proceedings of The Royal Society B: Biological Sciences, 2007
The influence of the Earth's magnetic field on locomotory orientation has been studied in many taxa but is best understood for homing pigeons (Columba livia). Effects of experimentally induced and naturally occurring perturbations in the geomagnetic field suggest that pigeons are sensitive to changes in geomagnetic parameters. However, whether pigeons use the Earth's magnetic field for position determination remains unknown. Here we report an apparent orientation to the intensity gradient of the geomagnetic field observed in pigeons homing from sites in and around a magnetic anomaly. From flight trajectories recorded by GPS-based tracking devices, we noted that many pigeons released at unfamiliar sites initially flew, in some cases up to several kilometres, in directions parallel and/or perpendicular to the bearing of the local intensity field. This behaviour occurred irrespective of the homeward direction and significantly more often than what was expected by random chance. Our study describes a novel behaviour which provides strong evidence that pigeons when homing detect and respond to spatial variation in the Earth's magnetic field-information of potential use for navigation.
Light-dependent magnetoreception: orientation behaviour of migratory birds under dim red light
Journal of Experimental Biology, 2008
Magnetic compass orientation in migratory birds has been shown to be based on radical pair processes and to require light from the short wavelength part of the spectrum up to 565 nm Green. Under dim red light of 645 nm wavelength and 1 mW m -2 intensity, Australian silvereyes and European robins showed a westerly tendency that did not change between spring and autumn, identifying it as a ʻfixed directionʼ response. A thorough analysis revealed that this orientation did not involve the inclination compass, but was a response based on the polarity of the magnetic field. Furthermore, in contrast to the orientation under shortwavelength light, it could be disrupted by local anaesthesia of the upper beak where iron-containing receptors are located, indicating that it is controlled by these receptors. The similarity of the response under dim red light to the response in total darkness suggests that the two responses may be identical. These findings indicate that the observed ʻfixed directionʼ response under dim red light is fundamentally different from the normal compass orientation, which is based on radical pair processes.
Avian magnetic compass can be tuned to anomalously low magnetic intensities
Proceedings of the Royal Society B: Biological Sciences, 2013
The avian magnetic compass works in a fairly narrow functional window around the intensity of the local geomagnetic field, but adjusts to intensities outside this range when birds experience these new intensities for a certain time. In the past, the geomagnetic field has often been much weaker than at present. To find out whether birds can obtain directional information from a weak magnetic field, we studied spontaneous orientation preferences of migratory robins in a 4 mT field (i.e. a field of less than 10 per cent of the local intensity of 47 mT). Birds can adjust to this low intensity: they turned out to be disoriented under 4 mT after a pre-exposure time of 8 h to 4 mT, but were able to orient in this field after a total exposure time of 17 h. This demonstrates a considerable plasticity of the avian magnetic compass. Orientation in the 4 mT field was not affected by local anaesthesia of the upper beak, but was disrupted by a radiofrequency magnetic field of 1.315 MHz, 480 nT, suggesting that a radical-pair mechanism still provides the directional information in the low magnetic field. This is in agreement with the idea that the avian magnetic compass may have developed already in the Mesozoic in the common ancestor of modern birds.
Scientific Reports, 2020
The magnetic compass is an important element of the avian navigation system, which allows migratory birds to solve complex tasks of moving between distant breeding and wintering locations. The photochemical magnetoreception in the eye is believed to be the primary biophysical mechanism behind the magnetic sense of birds. It was shown previously that birds were disoriented in presence of weak oscillating magnetic fields (OMF) with frequencies in the megahertz range. The OMF effect was considered to be a fingerprint of the photochemical magnetoreception in the eye. In this work, we used miniaturized portable magnetic coils attached to the bird’s head to specifically target the compass receptor. We performed behavioural experiments on orientation of long-distance migrants, garden warblers (Sylvia borin), in round arenas. The OMF with the amplitude of about 5 nT was applied locally to the birds’ eyes. Surprisingly, the birds were not disoriented and showed the seasonally appropriate mig...