Digestive Plasticity in Avian Energetics and Feeding Ecology

Abstract

This chapter focuses on changes in gastrointestinal (GI) structure and function and how they influence the supply of energy and nutrients for maintenance and production (growth, storage, and reproduction). There is considerable evidence that digestive features are influenced by factors such as diet quality and quantity in species from many avian orders including the Anseriformes (Ankney 1977; Drobney 1984; Prop and Vulink 1992), Galliformes (Gasaway 1976; Moss 1983), Columbiformes (Kenward and Sibly 1977), and Passeriformes (Davis 1961; Al- Dabbagh et al. 1987; Brugger 1991; Walsberg and Thompson 1990). The likely ecological importance of digestive adjustments is suggested by a number of theoretical arguments and some observations.