Factors affecting intraspecific diet variation of ducklings

Variability in resource use within populations of free-ranging animals can influence demographic and evolutionary processes. Yet in many systems, the extent of intra-population trophic niche variation and the environmental factors that contribute to this variance remain poorly understood. For example, dietary studies commonly group individuals and jointly classify the study population along the generalist to specialist continuum, even though diets of sub-populations and individuals can deviate significantly from the population average, particularly in heterogeneous environments. To evaluate the degree of intraspecific diet variation in a population of wild birds and to test potential linkages between dietary specialization and environmental gradients in relative resource abundance, we used hierarchical Bayesian stable isotope mixing models to estimate (i) assimilated diets of juvenile lesser scaup (Aythya affinis; hereafter scaup) and (ii) diet variation within and across lakes that harbor distinct assemblages of aquatic macroinvertebrates. We fount that lake-level variation in diet accounted for most of the variation across the study population, with little variation attributed…

Publisher

Environment and Climate Change Canada

Resources

3

Catalogue metadata updated

2024-12-10