Gulls contribute to olive seed dispersal within and among islands in a Mediterranean coastal area

Aim: To analyse the role of non-frugivorous birds on seed dispersal, seed dispersal by gulls is expected to be especially instrumental in island ecosystems, as these have a smaller subset of frugivores when compared to the mainland, and because long-distance dispersal is required for plant colonization. Here we investigated the seed dispersal of olives by gulls among ten islands of the same archipelago to reveal if gulls contribute to long-distance seed dispersal including different islands, and how gulls’ adaptation to domestic olives and individual differences in foraging activities affect their seed dispersal pattern.
Location: Balearic Islands in the Western Mediterranean Sea, Spain
Taxon: Yellow-legged gulls ( Larus michahellis), Domestic and wild Olives ( Olea europaea and O. europaea var. sylvestris)
Methods: We developed seed dispersal models of the two ecotypes of olives dispersed by gulls across an archipelago, based on GPS tracking data, gut passage time, and seed viability.
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