Dispersal of aquatic invertebrates by lesser black-backed gulls and white storks within and between inland habitats

Abstract Waterbirds can transport aquatic invertebrates internally, contributing to metapopulation dynamics between habitats in a terrestrial matrix. However, research into this dispersal process date has focused on individual field sites or laboratory studies. We investigated the dispersed by endozoochory lesser black-backed gull Larus fuscus wintering Andalusia, south-west Spain 2016–2017, comparing seven interconnected their movements, with different degrees of anthropogenization [three landfills, two saltpan complexes, natural lake, and large (370 km 2 ) ricefield area]. In ricefields, we also compared gulls those larger white stork Ciconia ciconia . A total 642 intact propagules (mainly plumatellid bryozoans, cladocerans, other branchiopods) were recorded excreta (faeces pellets) from storks. greater diversity abundance notably 43 individuals alien snail Physella acuta One was still alive pellet 3 weeks after being stored fridge. This represents first record within waterbird pellets. Viability confirmed for cladoceran Macrothrix rosea brine shrimp Artemia franciscana mainly saltpans. pellets had significantly fewer taxa per gram than storks faeces, respectively. Through high mobility, disperse artificial habitats, even landfills. They promote native bryozoans branchiopods, but spread invasive snails shrimp.