North Atlantic winter cyclones starve seabirds

Area of Science:

• Marine Ecology
• Avian Biology
• Climate Change Impacts

Background:

• North Atlantic winter cyclones cause seabird mass-mortality events ("winter wrecks"), impacting population dynamics.
• The origins and causes of death for seabirds in these events remain largely unknown.
• Understanding seabird vulnerability to cyclones is crucial, especially with changing climate patterns.

Purpose of the Study:

• To conduct the first ocean-basin scale assessment of cyclone exposure in North Atlantic seabirds.
• To investigate the energetic consequences of cyclonic conditions on seabird survival.
• To determine the primary drivers of seabird mortality during winter storms.

Main Methods:

• Coupled tracking data of ~1,500 individuals from five key seabird species with cyclone locations.
• Utilized a mechanistic bioenergetics model to explore energetic consequences of cyclonic conditions.
• Assessed seabird species and colony exposure to high-intensity cyclones across the North Atlantic.

Main Results:

• High-intensity cyclones impacted all studied seabird species and breeding colonies.
• Specific areas like the Labrador Sea, Davis Strait, Iceland, and Barents Sea showed higher impacts.
• Cyclones did not increase seabird energy requirements, suggesting prey-related mortality.

Conclusions:

• Seabird mortality during winter wrecks is primarily driven by prey unavailability or inability to feed during cyclones.
• This study provides critical data on seabird cyclone exposure amidst changing climate and cyclone regimes.
• Findings are essential for seabird conservation in the face of global warming.