Seabirds returning from foraging trips can be thrown hundreds of miles off course by a form of jet lag that arises when their body clocks fall out of sync with local time, according to The Guardian. Tracking data from Manx shearwaters on the west coast of the UK showed that rapid eastward flights home after trips over the Atlantic disrupted their sense of time and navigation.
The impact was limited on adult shearwaters because the birds were able to correct their bearings in flight. At most, they veered off course by about 15 degrees, adding an estimated 3 miles to a 600-mile journey. Less experienced birds were likely to fare worse, with first-time foragers at risk of flying off course by hundreds of miles.
Dr Patrick Lewin, a behavioural and sensory ecologist at the University of Oxford, set out to investigate wild birds with colleagues and analysed 20 years of GPS tracking data. The analysis revealed a clear effect when the birds flew east across lines of longitude as they returned home, leaving their clocks running up to an hour or so behind local time. Lewin said the bird's internal clock could be subject to a jet lag phenomenon, manifesting as birds flying off course.
Like many animals, shearwaters use the sun as a compass, relying on their body clock to track the time of day. Writing in Science, Lewin said the mismatch could make them drift off course. Prof Richard Holland of Bangor University, who was not involved in the study, called it a significant finding.