Biometals

, Volume 13, Issue 4, pp 325–331

Superparamagnetic Magnetite in the Upper Beak Tissue of Homing Pigeons

  • Marianne Hanzlik
  • Christoph Heunemann
  • Elke Holtkamp-Rötzler
  • Michael Winklhofer
  • Nikolai Petersen
  • Gerta Fleissner
Article

Abstract

Homing pigeons have been subject of various studies trying to detect magnetic material which might be involved in magnetic field perception. Here we focus on the upper-beak skin of homing pigeons, a region that has previously been shown to contain nerves sensitive to changes of the ambient magnetic field. We localized Fe3+ concentrations in the subcutis and identified the material by transmission electronmicroscopy (TEM) as aggregates of magnetite nanocrystals (with grain sizes between 1 and 5 nm). The particles form clusters of 1–3 μm diameter, which are arranged in distinct coherent elongated structures, associated with nervous tissue and located between fat cells. Complementary low-temperature magnetic measurements confirm the microscopic observations of fine-grained superparamagnetic particles in the tissue. Neither electron-microscopic nor magnetic measurements revealed any single-domain magnetite in the upper-beak skin tissue.

homing pigeon magnetoreception SAED analysis SQUID magnetometer ZFC-FC curves 

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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Marianne Hanzlik
    • 1
  • Christoph Heunemann
    • 1
  • Elke Holtkamp-Rötzler
    • 2
  • Michael Winklhofer
    • 1
  • Nikolai Petersen
    • 1
  • Gerta Fleissner
    • 2
  1. 1.Institut für Allgemeine und Angewandte GeophysikLudwig-Maximilians-UniversitätMunichGermany
  2. 2.Zoologisches InstitutJohann-Wolfgang-Goethe-UniversitätFrankfurt a. M.Germany

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