Avian navigation

Many species of birds can very reliably navigate over large distances, even from places they have never been to, and return to their desired destination, often over hundreds or even thousands of kilometres.

Homing pigeons, for example, can very consistently 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

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)

A 2024 study from Bangor University, UK, found that a species of Reed Warbler (Acrocephalus scirpaceus) appears to predominantly be using fine-detail variations in the Earth's magnetic field to navigate.

Eurasian reed warblers (Acrocephalus scirpaceus), can determine their position based on two magnetic field components that are also associated with direction finding, i.e. magnetic inclination and magnetic declination.

[…]

Based on our current results, it appears that birds can use a combination of magnetic inclination and magnetic declination to locate their position, even when the values of these cues do not match the geospatial variation of the total intensity of the Earth’s magnetic field. This suggests that a majority rule may apply, or possibly that the total intensity of the magnetic field does not form a part of the navigational map of birds."

See: Proceedings of the Royal Society, B, Volume 291 Issue 2034

Note that the way(s) in which the birds (and other animals) somehow sense the Earth's magnetic field in very fine detail is currently unclear. 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.

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.