Manx shearwaters can travel up to 1,000 kilometres from their nests in search of food, even though these trips are short compared with their annual migration of roughly 25,000 kilometres over the sea. Researchers have now identified an unexpected consequence of these journeys: the seabirds can experience jet lag.
The study, published in Science on Thursday, 29 October, analysed GPS data from 3,688 foraging trips made by 1,045 Manx shearwaters during the breeding season. Most colonies nest along the western coasts of Great Britain between February and July.
The research team, led by Tim Guilford, a professor at Oxford and director of the Navigation research group, focused on the birds’ frequent journeys rather than their winter migration. During the latter period, Manx shearwaters commonly travel along the coast of Argentina as far as the 50th parallel.
The researchers examined how the birds find their way back to their nests after crossing open ocean without visual landmarks. Previous research had shown that the species uses the Sun for navigation. The new findings indicate that, after travelling westward to feed, the birds return with a slight deviation from their course. This appears to produce a difference between their biological clock and solar time.
Sources: Le Monde Sciences.