by Gennady SHVETSOV, Cand. Sc. (Biol.), Head of the Section on Problems of Biological Navigation, RADUGA State R&D Center of the Russian Federation (town of Raduzhny, Vladimir Region)
Articles in this rubric reflect the opinion of the author.-Ey.
The problem of space orientation of animals-the mechanism of navigation and homing in more common terms-has been in the focus of attention at least ever since the time of Aristotle. Migration is best known among birds which periodically travel from north to south and back over vast distances. And the really amazing thing is, as proved by the results of experiments with the ringing of birds' legs, migratory birds usually return to their original, or native, breeding grounds.
The polar gull (Sterna paradisaea), for example, covers a distance of 60 thousand kilometers one way from the Arctic isles to the cliffs of Antarctica which takes it nearly three months one way. The golden plover (Charadrius apricarius) flies non- stop over the Pacific from Alaska to the Hawaiis for some 40 hours, rain or shine, covering a distance of three and a half thousand kilometers. This seems to be the record performance of this kind known to ornithologists today. To add color to the drama one also has to bear in mind that as often as not such overflights occur even despite the odds of heavy clouds and/or thick fog (blind flying) without even the slightest chance of sighting any visible landmarks on earth or up in heaven.
Or take the example of cuckoo fledglings which, brought up by foster parents, can fly all by themselves to the tropics over thousands of kilometers landing exactly in their traditional wintering grounds where they mix with birds of the feather from other places. A similar situation is observed with young starlings (with the only difference that they now fly to their wintering grounds earlier than their forefathers).
Or take another example-of the North American monarch or milkweed butterflies (Danaidae) which ... Read more