COS 81-3 - The influence of social cues on timing of animal migrations

Background/Question/Methods

Animal migration plays a central role in many ecological and evolutionary processes, yet migratory populations worldwide are increasingly threatened. Adjusting migration timing to match ecosystem phenology is key to survival in dynamic and changing ecosystems, especially in an era of human-induced rapid environmental change. Social cues are increasingly recognized as major components of migratory behavior, yet a comprehensive understanding of how social cues influence the timing of animal migrations remains elusive. Here, we introduce a framework for assessing the role that social cues play in animals’ temporal migration decisions across a range of scales. This framework allows for assessment of the role of social cues on migration along two gradients: (1) across temporal scales ranging from sub-daily to whether or not to migrate at all in and individual's lifetime; and (2) across several categories of social cues ranging from explicit (e.g., active cueing) to implicit (e.g., density dependency, conspecific competition). We apply this framework to 45 case studies identified via systematic review of published literature to elucidate the influence of social cues on timing of animal migrations.

Results/Conclusions

We find that a broad range of social cues frequently mediate migration timing at a range of temporal scales and across highly diverse migratory taxa (including mammals, birds, insects, fish, amphibians, and crustaceans) in both marine, terrestrial, and freshwater ecosystems. We further highlight that while rarely documented, several social cue mechanisms play important adaptive roles in timing migrations in two distinct ways: (1) matching migration timing with ecosystem dynamics across scales; and (2) reducing risk of predation during migration. Thus, social cues play a fundamental role in migration timing, with potentially widespread ecological consequences and implications for the conservation of migratory species. Further, our analysis establishes a framework to evaluate future findings at this intersection of behavioral ecology and global change biology.