Manx shearwaters can experience a form of jet lag when flying long distances across the North Atlantic, according to a new study published in Science. The disruption to their internal clocks appears to affect the birds’ ability to use the Sun as a compass.
The seabirds can travel hundreds of kilometers per day during trips from their breeding colonies to feeding grounds. They nest in burrows on coastal islands around the North Atlantic, with most breeding populations located around the United Kingdom and Ireland. About half of the species’ population lives in Wales.
Shearwaters may travel from a few dozen to more than 1,000 kilometers into the Atlantic before returning. Researchers believe they first estimate their location using a map-like sense that may involve smells, then use the Sun to determine their direction.
That method depends on an accurate internal clock because the Sun changes position throughout the day. A bird traveling south, for example, must adjust its direction relative to the Sun from sunrise through midday and sunset. Patrick Lewin, a behavioral and sensory ecologist at the University of Oxford and the study’s lead author, explained that the birds’ built-in clocks are not perfect.
The research indicates that long-distance journeys can leave the shearwaters’ clocks out of sync with the time of day. Because their navigation relies on the Sun, this internal misalignment produces a measurable skew in their compass.
Sources: Ars Technica.