Direct evidence for intercontinental dispersal of a snail via a bird

Abstract

Long-distance dispersal (LDD) is a critical process in the distribution of less-migratory organisms. Migratory birds are considered the principal vector of LDD, especially over extremely long distances such as between continents. However, there has been no evidence of LDD spanning thousands of kilometers, even via birds. In this study, we collected a freshwater snail attached to a Latham's snipe. This snail was identified as the genus Glyptophysa through morphological and molecular identification based on four genetic regions. Considering the migration route of the bird and the distribution of the molluscan genus, we conclude that the snail was attached to a bird which migrated over 4000 km across the ocean. This finding demonstrates the LDD on an intercontinental scale of an organism via a migratory bird, which many biologists have long presumed to occur.