Migration along orthodromic sun compass routes by arctic birds.

Flight directions of birds migrating at high geographic and magnetic latitudes can be used to test bird orientation by celestial or geomagnetic compass systems under polar conditions. Migration patterns of arctic shorebirds, revealed by tracking radar studies during an icebreaker expedition along the Northwest Passage in 1999, support predicted sun compass trajectories but cannot be reconciled with orientation along either geographic or magnetic loxodromes (rhumb lines). Sun compass routes are similar to orthodromes (great circle routes) at high latitudes, showing changing geographic courses as the birds traverse longitudes and their internal clock gets out of phase with local time. These routes bring the shorebirds from high arctic Canada to the east coast of North America, from which they make transoceanic flights to South America. The observations are also consistent with a migration link between Siberia and the Beaufort Sea region by way of sun compass routes across the Arctic Ocean.

[1]  J. Emlen,et al.  DISTANCE NAVIGATION IN THE ADELIE PENGUIN , 1964 .

[2]  Miss A.O. Penney (b) , 1974, The New Yale Book of Quotations.

[3]  K. Schmidt-Koenig,et al.  Animal Migration, Navigation, and Homing , 1978 .

[4]  W. Richardson Southeastward shorebird migration over Nova Scotia and New Brunswick in autumn: a radar study , 1979 .

[5]  B. Heller Circular Statistics in Biology, Edward Batschelet. Academic Press, London & New York (1981), 371, Price $69.50 , 1983 .

[6]  Philip K. Stoddard,et al.  Computer simulation of autumnal bird migration over the western North Atlantic , 1983, Animal Behaviour.

[7]  B. L. Olla,et al.  Shorebirds: migration and foraging behavior , 1984 .

[8]  T. Alerstam,et al.  Orientation along great circles by migrating birds using a sun compass , 1991 .

[9]  R. Robin Baker P. Berthold Orientation in Birds , 1992, Animal Behaviour.

[10]  Dr. Roswitha Wiltschko,et al.  Magnetic Orientation in Animals , 1995, Zoophysiology.

[11]  K. Able,et al.  Interactions in the flexible orientation system of a migratory bird , 1995, Nature.

[12]  W. Wiltschko,et al.  INTERACTION OF MAGNETIC AND CELESTIAL CUES IN THE MIGRATORY ORIENTATION OFPASSERINES , 1998 .

[13]  Backman,et al.  Orientation of snow buntings (Plectrophenax nivalis) close to the magnetic north pole , 1998, The Journal of experimental biology.

[14]  R. Wehner Navigation in context: grand theories and basic mechanisms , 1998 .

[15]  Thomas Alerstam,et al.  OPTIMAL MAP PROJECTIONS FOR ANALYSING LONG-DISTANCE MIGRATION ROUTES , 1998 .

[16]  T. Alerstam,et al.  Migration Patterns of Tundra Birds: Tracking Radar Observations along the Northeast Passage , 1999 .

[17]  T. Alerstam,et al.  Bird orientation at high latitudes: flight routes between Siberia and North America across the Arctic Ocean , 1999, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[18]  G. Gudmundsson,et al.  Sanderlings (Calidris alba) have a magnetic compass: orientation experiments during spring migration in Iceland. , 2000, The Journal of experimental biology.