Daytime calibration of magnetic orientation in a migratory bird requires a view of skylight polarization

  title={Daytime calibration of magnetic orientation in a migratory bird requires a view of skylight polarization},
  author={Kenneth P. Able and Mary A. Able},
THE orientation of migratory birds is based on a complex of interacting compass mechanisms (the geomagnetic field, stars, patterns of skylight polarization and, perhaps, the Sun)1,2. A magnetic compass develops in birds that have never seen the sky3–8, but the preferred direction of magnetic orientation may be modified during the first three months of life by exposing naive birds to either the clear daytime or night sky under conditions in which magnetic directions differ substantially from… 

Manipulations of polarized skylight calibrate magnetic orientation in a migratory bird

Abstract1.Young migratory birds enter the world with two representations of the migratory direction, one coded with respect to the magnetic field, the other with respect to celestial rotation. The

Interactions in the flexible orientation system of a migratory bird

MIGRATING birds rely on interacting compass senses: magnetic, star, polarized light and perhaps Sun compasses1,2. During the development of orientation mechanisms, celestial rotation of stars at

Evidence for calibration of magnetic migratory orientation in Savannah sparrows reared in the field

  • K. AbleM. A. Able
  • Environmental Science
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1999
The orientation system of migratory birds consists of a magnetic compass and compasses based upon celestial cues. In many places, magnetic compass directions and true or geographic compass directions

Magnetic compass of migratory Savannah sparrows is calibrated by skylight polarization at sunrise and sunset

Migratory birds use compass systems derived from the geomagnetic field, the stars, the sun and polarized light patterns. We tested whether birds use a single underlying reference system for

Development of sunset orientation in a migratory bird: no calibration by the magnetic field

Abstract The ontogeny of orientation mechanisms in migratory birds involves a complex of programmed learning rules and calibrations between the several compasses used during migration. Visual

The role of skylight polarization in the orientation of a day-migrating bird species

Results indicate that polarized skylight can be used for orientation when no other known cues are available, and in the hierarchy of cues of this species, the polarization pattern clearly ranks lower than information from the geomagnetic field.

Calibration of magnetic and celestial compass cues in migratory birds - a review of cue-conflict experiments

The analyses suggest that during the premigratory season, celestial information is given the greatest salience and used to recalibrate the magnetic compass by both juvenile and adult birds, and under natural conditions there may be a single calibration reference for all of the compass systems of migratory birds.

Response of a free-flying songbird to an experimental shift of the light polarization pattern around sunset

It is shown that both the experimental and the control birds being released after nautical twilight departed consistently towards south-southeast, a lacking difference in the departure direction of both groups may suggest that birds did not recalibrate any of the compass systems during the experiment.

The role of daytime cues in the development of magnetic orientation in a night-migrating bird

It is demonstrated that observing celestial rotation during daytime enables birds to choose the right end of the migratory axis for autumn migration at the Latvian test location.

Avian orientation at steep angles of inclination: experiments with migratory white–crowned sparrows at the magnetic North Pole

The experimental birds failed to select a meaningful magnetic compass course under overcast conditions at the magnetic North Pole, but could do so in geomagnetic fields deviating less than 3° from the vertical, while migratory orientation was successful at all sites when celestial cues were available.



Calibration of the magnetic compass of a migratory bird by celestial rotation

MIGRATORY birds use a variety of environmental stimuli in orientation. Species that migrate primarily at night can use compasses based on the geomagnetic field, stars, the Sun and patterns of

Skylight Polarization Patterns and the Orientation of Migratory Birds

The results reported here support the hypothesis that the relevant stimulus is the E-vector orientation rather than other parameters of skylight, e.g. intensity or colour patterns, degree of polarization.

Dynamic patterns of skylight polarization as clock and compass.

  • M. Brines
  • Physics
    Journal of theoretical biology
  • 1980

Skylight polarization patterns at dusk influence migratory orientation in birds

It is reported here that the migratory orientation of the white-throated sparrow (Zonotrichia albicollis), a nocturnal migrant, is affected by manipulations of the axis of skylight polarization, providing the first evidence that polarized light may be a relevant cue in migratory Orientation.

The development of migratory orientation mechanisms.

The processes and interactions of orientation mechanisms in migratory birds are synthesized into a framework that may help identify critical research questions and some problems of experimental design and the interpretation of results from experiments are discussed.

Magnetic Field Orientation of Migratory Savannah Sparrows With Different First Summer Experience

Three groups of hand-reared savannah sparrows (Passerculus sandwichensis) were given different exposure to the sky and an ambient magnetic field during their first summer to investigate the possible