Manx shearwaters return to their nests after spending weeks hunting at sea. New research suggests they experience jet lag on their journey home.
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birdsonline/Getty images
New research shows that humans aren’t the only species to suffer from jet lag: some birds appear to suffer from it too.
A study published in the journal Science have discovered that a type of seabird known as the Manx shearwater appears to be slightly disoriented during long flights across the Atlantic Ocean. This disorientation, the authors say, is due to the fact that the bird’s internal clock is not synchronized with the position of the sun in the sky.
Manx shearwaters are a common bird in the British Isles. They look a bit like seagulls, but “they’re actually very close to albatrosses,” said Patrick Lewin, a behavioral ecologist at the University of Oxford.
Shearwaters mate for life and when they breed, a pair lays only one egg.
Then they take turns incubating it: “One partner will sit on the egg nonstop while the other goes out to sea,” Lewin said.
For up to two weeks, hunting partners scour the North Atlantic in search of fish and squid, often traveling hundreds of kilometers from their nests.
Once these birds’ bellies are full, “they completely bombard it back to their colony,” Lewin said. Often they make the long journey home in just a day or two.
Which raised an interesting question: do Manx shearwaters feel jet lag (or perhaps more aptly, flap lag)?
To see if these little birds actually felt the effects of flying across time zones the way humans do, Lewin used a remarkable tool: For 20 years, his colleagues marked the birds with GPS trackers and collected data on their flights back and forth across the Atlantic.
He thought he could see the time difference in their flights. This is because Manx shearwaters are thought to use the sun to navigate.
“To use the sun as a compass, you need to know what time of day it is,” Lewin said.
In the morning the sun is in the east, at noon it is slightly to the south (if you are in the northern hemisphere) and in the evening it is in the west. If shearwaters had the wrong time of day, they would fly in the wrong direction.
This is exactly what Lewin and his colleagues saw. As the birds rushed toward their mates and eggs, they veered slightly off course. It wasn’t much: An error of seven degrees, the maximum deviation observed, only moved a bird about three miles away on a 600-mile journey. “It’s a very small addition,” he said.
“This paper is so cool,” said Alice Boyle, a biologist at the Center for Moving Animals at Western University in Ontario, Canada, who was not part of the study.
Boyle said almost every creature on the planet, from corals to chipmunks, must navigate their environment, but it’s rare to see a study showing navigation decisions in action. This is what makes this type of GPS work so valuable.
“It’s about using these wild birds that travel to completely remote places and we can learn a lot about how they do that,” she said.
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