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No. 55: Jan-Feb 1988

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Migrating Birds Collide With Magnetic Bump

Do birds utilize the earth's magnetic field for navigation? Many have so surmised; and there exists anecdotal evidence for it. A Swedish ecologist, T. Almberstam, decided to attempt scientific observations. At Norberg, in central Sweden, a huge deposit of magnetite creates a powerful magnetic anomaly. The deposit is 12 kilometers long by several wide. At low altitudes, the total magnetic intensity of the earth's field is 60% higher than normal. What happens when migrating birds fly into this magnetic bump?

"Although Almerstam found that many migrating birds showed no signs of avoiding the Norberg anomaly, and often managed to keep on the right course as they passed through it, there were definite indications that the birds' orientation might be affected under special circumstances. Some migrants flying at low altitudes, where the magnetic intensity was greatest and the inclination and declination distorted greatly, became disoriented briefly. They nervously landed and then circled around before taking off again. Other birds changed their altitude abruptly, dropping 100 metres in two minutes and breaking up their flock formations."

Certainly something is happening, but no one knows what.

(Anonmous; "Magnetic Anomaly Upsets Migrating Birds," New Scientist, p. 32, November 5, 1987.)

From Science Frontiers #55, JAN-FEB 1988. 1988-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987