It is often assumed that only plants with a fleshy fruit disperse inside vertebrate guts, i.e. by “endozoochory”. However, only 8% of European angiosperms have a fleshy fruit, and endozoochory of other plants by herbivorous or granivorous birds and mammals is widespread in nature. Many terrestrial and aquatic plants disperse via endozoochory by migratory waterbirds, providing long-dispersal dispersal.

Modern literature on plant dispersal by birds focuses mainly on the importance of frugivory and scatter-hoarding, yet recent studies show that endozoochory by migratory waterbirds is an important mechanism of long-distance dispersal for a broad range of plants. Nevertheless, there is a lack of empirical field studies that identify the plants dispersed by waterbirds in a comprehensive manner. In particular, so far there are no detailed studies of the level of spatial variation in the plant...