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Foster and Kreitzman - Seasons of Life - The sun, the stars, magnetic fields and the migration of animals

Identifier

020348

Type of Spiritual Experience

Background

A description of the experience

Seasons of Life – Russell G Foster and Leon Kreitzman

The sun not only moves across the sky as the earth rotates, but its apparent position also varies with latitude and time of year.  It is not known how animals compensate for this additional variance.  Furthermore, many species such as insects, fish and amphibians do not even have to view the sun directly but can infer its position because of the pattern of polarised light in the sky.  This is possible because the properties of skylight polarisation change predictably with the changing position of the sun.

Birds also use the stars, when visible, to provide compass information.  … Stephen Emlen provided the proof for this when he published his planetarium experiments on indigo buntings showing that they can orient in a non directional magnetic field by using directional cues from the stars…..

Birds also orient themselves by detecting magnetic fields.  In the mid twentieth century the German scientists Fritz Merkel placed European robins in a large cement cage that screened out all environmental clues; the birds were able to orient their ‘zugenruhe’ properly.  But when he put the birds into a large steel cage, which interrupted magnetic lines of force around the cage, the birds oriented randomly (Merkel and Wiltschko 1965).  Species as diverse as loggerhead turtle hatchlings and migratory birds can detect and orient within a magnetic field

The source of the experience

Foster and Kreitzmann

Concepts, symbols and science items

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Science Items

Activities and commonsteps

Activities

Commonsteps

References