What makes an individual move from a population? We are using stable isotopes and mark recapture techniques to test the hypothesis that individual variation in diet specialization (i.e. position on a niche axis of N and C) can predict the probability of that an individual remains in the population.
We predict that individuals feeding on the margins of the niche will be more likely to move from a population than individuals feeding on “common” resources. This work is applied to a community of fish that includes northern leatherside chub (Lepidomeda copei), a threatened fish in the Great Basin, USA.