Manx shearwaters race back to their nests after spending weeks hunting at sea. New research suggests they suffer from jet lag on the journey home. Birdsonline/Getty Images hide title toggle title i birdsonline/Getty Images New research shows that humans are not the only species that suffers from jet lag: some birds seem to experience it too. A study published in the journal Science found that a type of seabird known as the Manx shearwater appears to become slightly disoriented during long flights across the Atlantic Ocean. That disorientation, the authors say, is because the bird’s internal clock is not synchronized with the position of the sun in the sky. The Manx shearwater is a common bird in the British Isles. They look a bit like gulls, but “they’re actually very closely related to an albatross,” said Patrick Lewin, a behavioral ecologist at the University of Oxford. Shearwaters mate for life and when they reproduce, the pair lays only one egg. Then they take turns incubating it: “One member will sit on the egg non-stop while the other goes out to sea,” Lewin said. For up to two weeks, hunting companions scour the North Atlantic in search of fish and squid, often traveling hundreds of kilometers from their nests. Once these birds’ stomachs are full, “they absolutely bombard them back to their colony,” Lewin said. They often make the long trip home in about a day. Which raised an interesting question: do Manx shearwaters feel jet lag (or perhaps more accurately, flap lag)? To see if these little birds were really feeling the effects of flying across time zones like humans, Lewin used a remarkable tool: For 20 years, his colleagues had been tagging birds with GPS trackers and collecting data on their flights to the Atlantic and back. He thought he could see the jet lag in his flights. This is because Manx shearwaters are believed to use the sun to navigate. “To use the sun as a compass you have to know what time of day it is,” Lewin said. In the morning, the sun is in the east, at noon it is slightly south (if you are in the northern hemisphere), and then in the afternoon it is in the west. If shearwaters had the wrong time of day, they would fly in the wrong direction. That’s exactly what Lewin and his colleagues saw. When the birds ran back to their mates and their eggs, they veered slightly off course. It wasn’t much: An error of seven degrees, the maximum deviation observed, only diverted a bird from its path about three miles on a 600-mile trip. “It’s a really small addition,” he said. “This paper is great,” said Alice Boyle, a biologist at the Center for Animals on the Move at Western University in Ontario, Canada, who was not involved in the study. Boyle said virtually every creature on the planet, from corals to chipmunks, has to navigate their environment, but it’s rare to see a study that shows navigational decisions in action. That’s what makes this type of GPS work so valuable. “You use these wild birds that travel to completely remote places and we can learn a lot about how they do it,” he said.
