Top-down effects of foraging decisions on local, landscape and regional
biodiversity of resources (DivGUD)
Abstract
Foraging by consumers acts as a biotic filtering mechanism for
biodiversity at the trophic level of resources. Variation in foraging
behaviour have cascading effects on abundance, diversity, and functional
trait composition of the community of resource species. Here we propose
diversity at giving-up density (DivGUD), when foragers quit exploring a
patch, as a novel concept and simple measure to quantify these effects
at multiple spatial scales. In experimental landscapes, patch residency
of wild rodents decreased local α-DivGUD (via elevated mortality of
species with large seeds) and regional γ-DivGUD, while dissimilarity
among patches in a landscape (ß-DivGUD) increased. Thus, DivGUD provides
a framework linking theories of adaptive foraging behaviour with
community ecology allowing to investigate cascading indirect predation
effects across multiple trophic levels e.g. the ecology-of-fear
framework; feedbacks between functional trait composition of resource
species and consumer communities; and effects of inter-individual
differences among foragers on the biodiversity of resource communities.