Testing for the presence of magnetite in the upper-beak skin of homing pigeons
- 140 Downloads
We carried out magnetic and nonmagnetic experiments on fresh, upper-beak skin tissue samples isolated from six pairs of homing pigeons to test whether the tissue contains magnetite particles. Results of (1) room-temperature isothermal remanent magnetization (IRM) acquisition and alternating field (AF) demagnetization, (2) low-temperature demagnetization of saturation IRM acquired at 5 K in a field of 5 tesla (T) (SIRM5 K) after zero-field cooled (ZFC) and field cooled (FC) treatments, and (3) cycling of the saturation IRM acquired at 300 K in a field of 5 T (SIRM300 K) between 5 and 300 K, indicate the presence of magnetite in the measured samples. A significant loss of SIRM5 K below 20 K suggests the dominance of superparamagnetic (SPM) particles. The SIRM acquisition capacity of the female pigeon is stronger than that of the male pigeon in all four measured pairs, suggesting for the first time that the magnetite concentration is probably sex dependent. Light microscopic observation on the histological sections stained with Prussian Blue detected the presence of some tiny, dotted, dark-blue staining Fe3+ aggregates (size 1–4 µm) located directly beneath the subcutis within strands of connective tissue, nearby the rim of the regions full of red nuclei. The results of this study support the idea that homing pigeons may have a magnetite-based receptor, which potentially could be used for sensing the Earth’s magnetic field during navigation.
Keywordshoming pigeon Columbia livia magnetite SQUID magnetometer low-temperature magnetic property Prussian Blue reaction
Unable to display preview. Download preview PDF.
- Bunting H (1949) The histochemical detection of iron in tissue. Stain Technol 24:109–115Google Scholar
- Davila AF, Fleissner G, Winklhofer M, Petersen N (2003) A new model for a magnetoreceptor in homing pigeons based on interacting clusters of superparamagnetic magnetite. Phys Chem Earth 28:647–652Google Scholar
- Dunlop DJ, Özdemir Ö (1997) Rock magnetism: fundamentals and frontiers. Cambridge, Cambridge University Press. 573 ppGoogle Scholar
- Romeis B (1968) Miikroskopische Technik. Munich, Oldenbourg-Verlag. 183 ppGoogle Scholar
- Verwey EJW (1939) Electronic conduction of magnetite (Fe3O4) and its transition point at low-temperature. Nature 44:327–328Google Scholar
- Wang ZN, An N (2004) Encyclopaedia of pigeon cultivation (homing pigeon, ornamental pigeon and meat pigeon). Beijing, China Agriculture Press (in Chinese)Google Scholar
- Wiltschko R, Wiltschko W (1995) Magnetic orientation of animals. Berlin, Springer-VerlagGoogle Scholar