Pigeon navigation

Homing pigeons can very reliably find their way back to their adopted roosting place - even when they have been physically removed hundreds of kilometres away - and often without any knowledge of the removal route.

It's known that they use a variety of methods to navigate - including

• Detection of the Earth's magnetic field (see Magnetoreceptionplugin-autotooltip__plain plugin-autotooltip_bigMagnetoreception
  
  A number of animal species, including bacteria, arthropods, molluscs, fish, birds and mammals are known to be able to sense magnetic fields.
  
  "Animals use geomagnetic fields for navigational cues, yet the sensory mechanism underlying magnetic perception remains poorly understood.)
• Olfactory clues
• Star patterns (at night)
• Visual 'map' memories,
• Ambient light polarisation
• Low-frequency sound identification
• Landmark following (e.g. man-made roads etc)

No consensus exists amongst biologists, however, regarding which systems dominate, their interactions, and how the birds maintain the extreme accuracy that they have.

See : Wikipedia

Also see Marine Turtle Migrationplugin-autotooltip__plain plugin-autotooltip_bigMarine Turtle Migration

Several species of marine turtle accurately migrate thousands of kilometers for nesting. Some species return to the exact beach where they were hatched. There are various proposed explanations for the behaviour, including magnetic navigation. But an experiment by and Monarch Butterfly migrationplugin-autotooltip__plain plugin-autotooltip_bigMonarch Butterfly migration

"Monarch butterfly migration is the phenomenon, mainly across North America, where the subspecies Danaus plexippus plexippus migrates each summer and autumn to and from overwintering sites on the West Coast of California or mountainous sites in Central Mexico.