Data from: Ecological release from aquatic predation is associated with the emergence of marine blenny fishes onto land

An ecological release from competition or predation is a frequent adaptive explanation for the colonisation of novel environments, but empirical data is limited. On the island of Rarotonga, several blenny fish species appear to be in the process of colonising land. Anecdotal observations have implied aquatic predation is an important factor in prompting such amphibious fish behavior. We provide evidence supporting this hypothesis by demonstrating amphibious blennies shift their abundance up and down the shoreline to remain above predatory fishes that periodically move into intertidal areas during high tide. A predation experiment using blenny mimics confirmed a high risk of aquatic predation for blennies; significantly higher than predation experienced on land. These data suggest predation has played an active role in promoting terrestrial activity in amphibious blennies, and provide a rare example of how ecological release from predation could drive the colonisation of a
novel environment.