ANDRÉANNE BEARDSELL

Effects of indirect trophic interactions on Arctic insectivorous birds

Indirect trophic interactions, between prey sharing a predator, can influence the abundance and coexistence of species at the community level. These interactions are widespread in the natural environment and despite a large body of work on them, it is difficult to determine the resulting interaction between prey sharing a predator. One reason for this is the difficulty of defining a realistic functional and numerical response of the predator. Arctic terrestrial vertebrate communities provide a context for studying indirect interactions due to the relative simplicity of the food web and the ability to directly observe predator-prey interactions. This project integrates mechanistic functional responses and numerical predator response scenarios to improve our understanding of indirect interactions in a system characterized by a generalist predator (fox), a cyclic prey (lemmings), a non-predator regulated prey (goose), and an incidental prey (shorebirds).