Study
Regional magnetic fields as navigational markers for sea turtles
Lohmann, Kenneth J.; Cain, Shaun D.; Dodge, Sarah A.; Lohmann, Catherine M. F.
Science, 2001
Hatchling loggerhead turtles were tethered in a water arena surrounded by coils reproducing the magnetic field found at specific locations along their migratory route. The direction each turtle swam was recorded.
- Studied in
- Caretta caretta
- Sample size
- hatchling loggerhead turtles tested in a magnetic coil system
Turtles swam in directions appropriate to the location whose magnetic signature they were exposed to, orienting differently for fields matching different points on the route — without ever having been there.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Hatchling turtles inherit responses to regional magnetic signatures, functioning as an inherited navigational map.
How NatureHQ reads it
This is the strongest single result in the map-versus-compass debate, and the reason it is persuasive is that the animals were naive: a hatchling that has never migrated cannot have learned these responses. It shows position-appropriate orientation rather than a map in any richer sense, and the magnitude of the field changes used is larger than a turtle would meet in a short journey.
- Tethered hatchlings in a tank, which constrains the behaviour available.
- Shows appropriate orientation, not that the animal knows where it is.
- Field manipulations are coarse relative to natural gradients.
Putting a newly hatched turtle in a magnetic field from a thousand miles away
Does a turtle that has never left the beach already know what to do at a place it has never been?
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Animal navigation
Hatchling turtles that have never migrated still swim the right way for where they are
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.
Sea turtles
Put a turtle in a tank and reproduce the magnetic field of a place hundreds of kilometres north of where it actually is, and it swims south — towards where it would need to go if it really were there.
Published by: American Association for the Advancement of SciencePublished in Science or Science Advances (AAAS).
doi.org/10.1126/science.1064557
Checked against Crossref and OpenAlex 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 2026-08-09.