Data from: How far can frugivorous birds disperse seeds during migration?

Long-distance seed dispersal plays a crucial role in shaping plant
distributions. The annual migration of millions of frugivorous birds holds
substantial potential for the long-distance dispersal of fleshy-fruited
plants, which are a major component of forests and woodlands globally.
However, quantitative estimations of seed-dispersal distances mediated by
migrant frugivorous birds are still lacking. Here, we uniquely combine
GPS-tracked movement data of thrushes migrating across Europe (n = 38
individuals) with empirical data on fruit consumption, flight departure
and speed, and seed retention times in the birds’ gut to mechanistically
simulate dispersal events. Our results reveal that, during migratory
flights, frugivorous birds can disperse seeds over tens to hundreds of
kilometres, depending on the plant species (range across species: mean =
9–45 km; P99.9 = 42–221 km; max. = 58–521 km). In contrast, most dispersal
distances (P99.9) by non-migratory movements were within 1 km.
Smaller-seeded species disperse farther due to their longer seed retention
times. Our study fills an important knowledge gap on the large-scale
dispersal of fleshy-fruited plants by migratory birds and uncovers
interspecific, trait-based differences in their long-distance dispersal
capacity.