Oecologia

, Volume 95, Issue 2, pp 164–170

Feeding-patch choice by red deer in relation to foraging efficiency

An experiment
  • Rolf Langvatn
  • Thomas A. Hanley
Original Papers

DOI: 10.1007/BF00323486

Cite this article as:
Langvatn, R. & Hanley, T.A. Oecologia (1993) 95: 164. doi:10.1007/BF00323486

Abstract

We tested the idea that ruminants allocate their feeding time to habitat patches in relation to foraging efficiency. We used five tame red deer (Cervus elaphus) in an enclosure planted with four treatment of timothy grass (Phleum pratense) differing in their stage of growth. Older swards offered higher biomass but lower nutritional quality than younger swards. We observed time spent feeding in each treatment during each of seven trials. We measured goodness-of-fit between observed times and predictions from two alternative hypotheses differing in optimization strategy (maximizing versus matching), and a third, null hypothesis. We tested the hypotheses using two alternative currecies: digestible protein, and digestible dry matter or energy. Although digestible protein concentration and dry-matter digestibility were highly correlated (r=0.763, P<0.001), the wider range of digestible protein made it the much more sensitive measure of forage quality. Distributions of feeding time closely matched estimated intake rates of digestible protein (RinfPredsup2=0.899) across all animals and trials. The other hypotheses were rejected. The results have important ecological implications in showing the underlying role of food in the selection of habitat by ruminants, and that simple, mechanistic models of forage intake and digestion can be scaled up to the level of animal behavioural choices.

Key words

Herbivore-plant interactionsForaging ecologyHabitat selectionRuminantsCervus elaphus

Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • Rolf Langvatn
    • 1
  • Thomas A. Hanley
    • 2
  1. 1.Norwegian Institute for Nature ResearchTrondheimNorway
  2. 2.Pacific Northwest Research Station, Forestry Sciences LaboratoryUSDA Forest ServiceJuneauUSA