Overview
- The study, published Thursday Oct. 29 in Science, used 20 years of GPS data from 1,045 Manx shearwaters and thousands of foraging trips to test navigation in the wild.
- Researchers found rapid longitudinal travel can leave birds’ internal clocks out of sync with local solar time and cause predictable sun‑compass deviations of up to about 15 degrees.
- Statistical models showed the time‑shift explanation matched the observed directional errors better than alternatives based on changes in Earth’s magnetic field.
- The orientation errors were small enough to add only a few kilometres to typical trips and did not stop adult shearwaters returning, yet they persisted even when coastlines and landmarks were visible.
- Authors say the next steps are to study whether these clock mismatches build up for inexperienced migrants and whether physiological effects analogous to human jet lag affect behavior or survival.