Data for: Early-life behavior predicts first-year survival in a long-distance avian migrant

Early-life conditions have critical, long-lasting effects on the fate of
individuals, yet early-life activity has rarely been linked to subsequent
survival of animals in the wild. Using high-resolution GPS and
body-acceleration data of 93 juvenile white storks (Ciconia ciconia), we
examined the links between behavior during both pre-fledging and
post-fledging (fledging-to-migration) periods and subsequent first year
survival. Juvenile daily activity (based on overall dynamic body
acceleration) showed repeatable between-individual variation, the
juveniles’ pre and post-fledging activity levels were correlated, and both
were positively associated with subsequent survival. Daily activity
increased gradually throughout the post-fledging period, and the
relationship between post-fledging activity and survival was stronger in
individuals who increased their daily activity level faster (an
interaction effect). We suggest that high activity profiles signified
individuals with increased pre-migratory experience, higher individual
quality and perhaps more proactive personality, which could underlie their
superior survival rates. The duration of individuals’
fledging-to-migration periods had a hump-shaped relationship with
survival: higher survival was associated with intermediate rather than
short or long durations. Short durations reflect lower pre-migratory
experience, whereas very long ones were associated with slower increases
in daily activity level which possibly reflects slow behavioral
development. In accordance with previous studies, heavier nestlings and
those that hatched and migrated earlier had increased survival. Using
extensive tracking data, our study exposed new links between early-life
attributes and survival, suggesting that early activity profiles in
migrating birds can explain variation in first-year survival.