Data from: Seasonal contrasts in individual consistency of oriental honey buzzards’ migration

Individual consistency in migration can shine light on the mechanisms of
migration. Most studies reported that birds are more consistent in the
timing than in the routes or stopover sites during migration, but some
specialist species showed the opposite patterns, being more consistent in
spatial than temporal aspects of migration. One possible explanation for
this contrast is that specialists rely on particular food or habitat
resources, which restrict the migratory routes they can take, leading to
high spatial consistency. If this is the case, the effect of specialist
foraging should become apparent only when birds forage, instead of fasting
and flying continuously. To test this effect, we analysed individual
consistency in migration of the oriental honey buzzard (Pernis
ptilorhynchus), a specialist raptor that feeds on honeybees and wasps,
using a long-term tracking data set. As honey buzzards make extended
stopovers during which they forage in spring but not in autumn, the
spatial consistency should be higher in spring than in autumn. Honey
buzzards were highly consistent in both their migratory routes and
stopover sites in Southeast Asia, but only during spring migration. Our
results highlight an important link between species’ migratory consistency
and foraging ecology.