Manx Shearwaters Adjust Foraging Strategies Based on Wind Conditions

Seabirds are among the most threatened group of birds globally, facing challenges such as climate change, overfishing, and habitat destruction. In this context, understanding their behavior and survival strategies is crucial. A recent study led by researchers from Bangor University sheds light on the extraordinary decision-making abilities of Manx shearwaters, a species of seabird, and how they navigate the complexities of wind and ocean to find food.

The Challenge of Finding Food in a Vast Ocean

Manx shearwaters are pelagic birds, meaning they spend much of their lives far from land, soaring over open oceans. Their primary challenge is finding enough food, such as small fish and plankton, to sustain themselves and their offspring during long breeding seasons. However, the open ocean offers no visible markers, and prey can be sparsely distributed.

The study, published in Current Biology, examined how shearwaters balance the energetic cost of flying with the benefits of food acquisition. The findings reveal that these birds make sophisticated foraging decisions based on prevailing wind conditions. Dr. Stephanie Harris, the lead author, and her colleagues have shown that wind plays a vital role in shaping the shearwaters’ foraging strategies.

The Role of Wind in Foraging

Dr. Harris’s research demonstrated that shearwaters adjust their foraging behavior depending on wind conditions. On windy days, the birds opt to search for food in areas where flying requires less energy, strategically using the wind to reduce effort. In calmer weather, when wind assistance is minimal, the birds rely on their knowledge of high-probability feeding zones, targeting areas where they anticipate abundant prey.

“Seabirds are faced with a huge ocean in which to find food, and being able to plan where to go is important,” Dr. Harris explains. “The implication is that shearwaters have a plan for where they are going to feed and also an understanding of how much energy it will cost to get there based on the wind.”

This dual strategy showcases the shearwaters’ ability to weigh environmental factors against energetic costs, demonstrating remarkable adaptability in an unpredictable and challenging environment.

Technology Revolutionizing Research

To uncover these insights, the research team relied on advanced tracking technology that has only recently become viable. Using miniature devices weighing as little as seven grams, scientists could track not only the birds’ movements across vast stretches of ocean but also measure their wingbeat frequency. This technology is akin to the accelerometers found in smartphones, offering highly detailed data on the birds’ flight dynamics.

The fieldwork was conducted at Bardsey Bird Observatory in North Wales and Copeland Bird Observatory in Northern Ireland, both critical breeding sites for Manx shearwaters. The tracked data allowed researchers to compare foraging patterns between the two colonies, further emphasizing how local wind conditions influence feeding behavior.

Implications of Climate Change

One of the key takeaways from the study is how changes in climate could impact seabirds. Climate projections for the UK predict a reduction in summer wind speeds, a factor that may directly affect the foraging efficiency of wind-dependent seabirds like the Manx shearwater.

Dr. Line Cordes, a senior author of the study and now based at the Norwegian Institute for Nature Research, highlighted the importance of this finding. “Understanding the role of winds in how seabirds forage will be crucial to predicting how they may be affected by future environmental changes.”

With reduced wind speeds, Manx shearwaters and other seabird species may need to expend more energy searching for food, potentially leading to lower breeding success and population declines. Given that many seabird species are already threatened by human activities such as overfishing and plastic pollution, climate-induced changes in wind patterns could exacerbate existing challenges.

Manx Shearwaters as Ecological Sentinels

Manx shearwaters are more than just extraordinary navigators; they serve as ecological indicators of ocean health. Their ability to forage efficiently depends on abundant prey, which in turn relies on healthy marine ecosystems. The insights gained from studies like this one provide valuable information for conservation efforts, helping to prioritize actions to protect seabird populations and the ecosystems they depend on.

Researchers are optimistic that continued advances in tracking technology and ecological modeling will yield deeper insights into seabird behavior and adaptation. This understanding could inform policies aimed at mitigating the impact of climate change and other anthropogenic threats on seabird populations.

Reference: Stephanie M. Harris et al, Adjustable wind selectivity in shearwaters implies knowledge of the foraging landscape, Current Biology (2025). DOI: 10.1016/j.cub.2024.12.017