Collaborative Research: Responses of Mammalian Herbivores to Spatial Heterogenetiry Expressed at Multiple Scales

Washington State University, Pullman WA

Investigators

Abstract

Collaborative Research: Responses of Mammalian Herbivores to Spatial Heterogeneity Expressed at Multiple Scales Project Summary Vertebrate herbivores (animals like deer and cattle and prairie dogs) are important parts of the earth's natural systems. These animals affect the types of plants that grow on landscapes, they influence the way that materials are cycled between soil and plants, and they control the behavior of important, large-scale processes like wildfire. Many of these effects of herbivores on ecosystems depend on the way they move while they are foraging. Herbivore movement, in turn, seems to respond to spatial patterns in vegetation. However, although responses of herbivores to spatial heterogeneity in plants is fundamental to understanding the role of herbivores in nature, these responses remain poorly understood. We propose experiments to understand how herbivores of various sizes (ranging from mice to elk) respond to complex patterns in the spatial arrangement of foods. These experiments will answer 3 basic questions: Are there particular sources of heterogeneity that exert a predominant influence on herbivore movement patterns? Does heterogeneity in foods allow herbivores to forage more efficiently, that is, to obtain more energy and nutrients per unit of foraging effort? Are there simple mathematical models that can faithfully represent the responses of herbivores to spatial patterns in plants? This work promises to reveal an important interaction in ecological systems. Describing this interaction will advance understanding of nature and will enhance our ability to manage processes that are vital to human economies.