Study
Magnetic compass of European robins
Wiltschko, Wolfgang; Wiltschko, Roswitha
Science, 1972
Robins showing migratory restlessness were tested in orientation cages inside coil systems that could alter the direction and inclination of the surrounding magnetic field, with the sky excluded. Horizontal direction and vertical inclination were manipulated separately.
- Studied in
- Erithacus rubecula
- Sample size
- European robins in orientation cages under altered fields
Birds reoriented when the horizontal component was turned, showing they use the magnetic field for direction. Reversing the horizontal component alone did not reverse their heading; reversing the vertical inclination did. The compass reads the angle the field makes with gravity, not which end points north.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Birds possess an inclination compass, distinguishing poleward from equatorward rather than north from south.
How NatureHQ reads it
This is the finding that should replace "birds have a compass in their heads" wherever that sentence appears. A magnetic compass reads polarity; a bird reads the angle of the field lines against the ground, which is a different instrument giving a different answer. It works perfectly well and it would be useless at the magnetic equator, and it explains why a bird carried across the equator has to reinterpret the same field.
- Cage orientation is intention rather than flight, with all the caveats that carries.
- One species; the inclination compass is now known widely among migrants but was established here in robins.
- The receptor mechanism is not identified by the behavioural result and remains contested.
Reversing a magnetic field the wrong way round on purpose
Birds orient by the magnetic field in total darkness. Is their compass the kind in a hiker’s pocket?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Bird migration
A bird’s magnetic compass tells poleward from equatorward, not north from south
Magnetoreception
That animals steer by the Earth’s magnetic field is not in doubt. What physically detects it has been argued for fifty years and is still unresolved.
Magnetoreception
Knowing which way is north is a different problem from knowing where you are, and the evidence for the two is very different in strength.
Published by: American Association for the Advancement of SciencePublished in Science or Science Advances (AAAS).
doi.org/10.1126/science.176.4030.62
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-10.