Greylag geese (Anser anser) initiate group flight based on the number and identities of callers

In a free-living greylag goose population of 133 birds, the number and identities of flock members in the calling chorus predicted both successful flight initiation and the size of the resulting flying group.

• Why it matters: Collective movement requires coordination, yet the specific vocal cues and who answers them are unclear for how cohesion is maintained during departures.
• What they did: The study recorded flight-initiation attempts, counting Locomotion and Pre-flight callers and tracking outcomes, then related caller composition to success and to flying group size and composition.
• The result: More Locomotion callers was linked to higher success and larger flying groups, including family and non-family fliers; more Pre-flight callers also predicted success, with only a marginal effect on group size, and family vocal responses increased departure probability.

AI summary of the abstract · may contain errors · not medical advice · read the paper.