The ease with which aquatic snails can colonize new ponds and lakes, and their widespread distributions throughout suitable habitat suggest they frequently disperse over large areas. However, snails cannot cross land to reach another waterbody by themselves. In my PhD project, I investigate the hypothesis that waterbirds transport aquatic snails between waterbodies. Experimentally, we concluded that many snail species are able to be transported by waterbirds, both externally (adhering to feet or bill) or internally (in the digestive system).
However, this does not guarantee actual dispersal in the field. Therefore, we here propose to analyse potential gene flow due to waterbirds, therefore requiring Donana as a unique area for our study. By comparing gene flow between those isolated waterbodies that are visited by many birds to those hardly visited by birds, we can determine wether or not birds are actually able to disperse aquatic snails in the field.