# Jet Lag Disrupts Navigation in Foraging Manx Shearwaters Oxford study reveals how internal clock desynchronization impacts migratory bird navigation accuracy. - **Source:** [Science | The Guardian](https://www.theguardian.com/science) - **Published:** 2026-10-29 - **Topic:** [Business](https://brifing.si/c/business) - **Original article:** - **On Brifing:** https://brifing.si/s/12ac87c3-2568-4598-8bbc-272c1807dd36 ## Biological Clock and Navigation Manx shearwaters rely heavily on the sun as a primary compass for long-distance navigation. Because the sun shifts position as the Earth rotates, these birds must synchronize their internal body clocks with local time. This study investigates how rapid eastward flights disrupt this synchronization, effectively causing a form of avian jet lag. ## Twenty Years of Tracking Dr. Patrick Lewin and his colleagues at the University of Oxford analyzed two decades of GPS tracking data from wild birds. This research moves beyond traditional laboratory settings to observe how shearwaters behave in their natural environment. The data specifically highlights navigation patterns during return flights across various lines of longitude. ## Impact on Adult Birds Adult shearwaters demonstrate a remarkable ability to correct their bearings while in flight. Even when their internal clocks lag by approximately one hour, they only veer off course by about 15 degrees. This minimal deviation adds roughly 3 miles to a 600-mile journey, showing that experienced birds possess effective compensatory mechanisms. ## Vulnerability of Inexperienced Foragers The study identifies a significant disparity between adult birds and first-time foragers. While adults can reorient themselves, inexperienced birds lack the necessary map sense to correct course errors. Consequently, these younger birds are at a much higher risk of flying hundreds of miles off course during their initial migratory return trips. ## Sun Compass Mechanism Failure The birds' reliance on the sun compass creates a specific vulnerability when local time and internal clocks mismatch. When the sun appears farther across the sky than expected, the birds drift from their intended path. This error persists even when birds follow coastlines, suggesting the sun remains their primary navigational anchor. ## Evidence from Coastal Landmarks Surprisingly, the navigation errors remained consistent even when birds followed recognizable coastlines. This finding reinforces the theory that the sun compass plays a central role in their orientation, overriding visual landmarks. The data suggests that internal timing is a more critical factor for these birds than previously understood in wild settings. ## Expert Perspective on Findings Prof. Richard Holland of Bangor University notes that this study confirms findings from controlled experiments within wild animal populations. While the consequences of these small errors for returning birds remain unclear, the research underscores the vital importance of biological rhythms in managing complex animal behaviors across various ecological and migratory contexts. ## Broader Implications for Biology This research highlights the necessity of understanding biological rhythms across multiple environmental contexts. As scientists continue to map these behaviors, the role of internal clocks in animal survival becomes increasingly evident. Future studies may further clarify how these navigational shifts impact the long-term fitness and survival rates of migratory seabird populations. ## Sources covering this story - https://www.theguardian.com/science/2026/oct/29/jet-lag-throws-seabirds-off-course-nature — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._