A major direction of our research focuses on an examination of individuals’ trophic niches using novel stable isotope-based metrics and direct stomach content analysis.  For example, we are able to conduct hundreds of stomach content analyses on individual fishes (snapper, Nassau grouper) in tidal creeks using a stomach regurgitation technique.  Such large sample sizes, including repeated sampling of individual fishes through time, allows for unique insight into diets of fishes.  We use these data to examine the incidence of individual specialists within populations.  Despite a tradition that considered individual specialization within a species to be rare or weak, recent studies have suggested it is widespread and can play a critical role in ecological and evolutionary processes.  Bolnick et al. (2003) defined an “individual specialist” as an individual whose niche is substantially narrower than its population’s niche for reasons not attributable to sex, age, or discrete morphological group.  Populations with a relatively large niche width may reflect the incidence of individual trophic specialists.  That is, particular individuals specialize on a sub-set of the diverse prey items available, and thus have a unique niche.  Alternatively, theremay be no scope for individual specialization in areas with low prey diversity, such as fragmented creeks, and thus all individuals converge on the same trophic role/niche.  The creek fragmentation gradient in the Bahamas provides a unique opportunity to examine how a human activity (fragmentation of landscapes) may affect the incidence of individual specialization wthin populations of ecologically critical fish species.

Layman, C.A., Quattrochi, J.P., Peyer, C.M., and Allgeier, J.E. 2007. Niche width collapse in a resilient top predator following ecosystem fragmentation. Ecology Letters..