Multispecies migratory connectivity indicates hemispheric-scale risk to bird populations from global change

Area of Science:

• Ecology
• Conservation Biology
• Environmental Science

Background:

• Global biodiversity conservation relies on understanding migratory species' extinction risks.
• Migratory connectivity, the seasonal linking of populations, is crucial for assessing these risks.
• Environmental changes interact with migratory patterns, posing significant threats.

Purpose of the Study:

• To develop a novel ecological risk assessment framework for migratory species.
• To quantify the relative risk of population declines across the Western Hemisphere.
• To identify high-risk migratory connections and vulnerable regions.

Main Methods:

• Integrated movement data from over 329,000 birds across 112 species.
• Developed a "multispecies migratory connectivity" parameter to represent exposure to global change.
• Combined exposure, projected climate/land-cover change (hazard), and species vulnerability scores to estimate risk.

Main Results:

• Multispecies migratory connectivity was the strongest driver of extinction risk.
• Connections between Canadian breeding grounds and South American non-breeding grounds face the greatest risk.
• Over half of very high-risk connections involved breeding regions in the eastern United States.

Conclusions:

• A three-part risk assessment framework effectively evaluates threats to migratory species.
• Long-distance migrants, particularly those utilizing eastern North American breeding grounds, are highly susceptible.
• Findings support international collaboration for year-round conservation of migratory bird populations.