Limited potential for bird migration to disperse plants to cooler latitudes

This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData availability: All data used in the analyses are available through the Dryad Digital Repository (https://doi.org/10.5061/dryad.15dv41nx3). The dated phylogeny of seed plants (Spermatophyta) used to obtain our phylogenetic tree is available through GitHub (https://github.com/FePhyFoFum/big_seed_plant_trees/releases). Data on bird body weight used for size classification (Supplementary Fig. 2) were obtained from EltonTraits 1.0 available through Figshare (https://doi.org/10.6084/m9.figshare.c.3306933).Code availability: The R scripts used to generate all results and figures are available through the Dryad Digital Repository (https://doi.org/10.5061/dryad.15dv41nx3).Climate change is forcing the redistribution of life on Earth at an unprecedented velocity1,2. Migratory birds are thought to help plants to track climate change through long-distance seed dispersal3,4. However, seeds may be consistently dispersed towards cooler or warmer latitudes depending on whether the fruiting period of a plant species coincides with northward or southward migrations. Here we assess the potential of plant communities to keep pace with climate change through long-distance seed dispersal by migratory birds. To do so, we combine phenological and migration information with data on 949 seed-dispersal interactions between 46 bird and 81 plant species from 13 woodland communities across Europe. Most of the plant species (86%) in these communities are dispersed by birds migrating south, whereas only 35% are dispersed by birds migrating north; the latter subset is phylogenetically clustered in lineages that have fruiting periods that overlap with the spring migration. Moreover, the majority of this critical dispersal service northwards is provided by only a few Palaearctic migrant species. The potential of migratory birds to assist a small, non-random sample of plants to track climate change latitudinally is expected to strongly influence the formation of novel plant communities, and thus affect their ecosystem functions and community assembly at higher trophic levels.European Union Horizon 2020Regional Government of AsturiasSpanish ‘Ramón y Cajal’ fellowshipSpanish MICINNSpanish ‘Juan de la Cierva Incorporación’ fellowshipPortuguese Foundation for Science and TechnologyRoyal Commission for the Exhibition of 1851Arcadi