Dispersal is the movement of organisms from one patch of habitat to another. This can have major consequences for ecological processes such as predator-prey interactions, as well as evolutionary processes such as local adaptation. Despite the recognition of the importance of dispersal, little is known about how this process actually occurs in biological systems. In this project, we will investigate how an individual’s traits and the environmental conditions it experiences determine whether or not that individual disperses to a different patch. We will perform field experiments in artificial ponds using backswimmers, an aquatic insect common to the ponds in and around the Koffler Scientific Reserve. We will ask whether an individual’s quality (i.e. size, energy reserves, etc.) influences its propensity to disperse away from a patch when it is exposed to a predator, the pumpkinseed sunfish.
Additional Scientific Information
Most studies of the proximate causes of dispersal consider only one factor independently of any others; however, we know from observing patterns of movement across landscapes that dispersal is a complex process that is likely influenced by several factors working simultaneously. In this project, we will conduct a mesocosm experiment to determine whether interactions between individual phenotype and environmental condition play a role in individual dispersal decisions in backswimmers, a flight-capable aquatic insect. Each mesocosm will be stocked with plankton and artificial vegetation to simulate natural pond environments. One caged pumpkinseed sunfish predator will be added to half of these mesocosms so that backswimmers will be able to detect visual and olfactory cues from the fish, but the fish will not be able to consume the backswimmers. Juvenile backswimmers will be reared in the laboratory under two different diet conditions to produce individuals of high and low quality. Once these backswimmers develop into adults, they will be added to the mesocosms. We will measure dispersal rates out of mesocosms to determine whether individual phenotype (individual quality) interacts with environmental condition (predation risk), to determine dispersal rates.
Principal Investigator: Locke Rowe
Researcher(s): Celina Baines