Skip to main content
SLU publication database (SLUpub)

Conference abstract2007Peer reviewed

Free-ranging moose (Alces alces) in winter: Testing a general model of herbivore foraging on a large ungulate

Lundmark, Caroline; Ball, John

Abstract

Wildlife biologists have increasingly relied on testing models to improve their understanding of the animals and ecosystems they manage. The use of foraging models specific to herbivores has increased dramatically in the last decades, and they are now a central part of wildlife management because they provide reasonably simple models to understand why animals select certain foods or habitats. We cannot manage herbivores or their habitats in the best way unless we truly understand their behaviour. For herbivores, one of the milestones in foraging theory was the mechanistic model developed by Spalinger and Hobbs in 1992. The model has been supported in several experiments on numerous captive herbivore species, often accounting for much of the variability in short term intake rate and providing insight into which foods are preferred and why. In most studies however, the measurements of the needed model parameters were confined to only a few minutes in the beginning of a foraging bout, which is a remarkably short duration for larger herbivores which may have foraging bouts exceeding an hour. In addition, most previous studies have used captive food-deprived animals, which are likely to feed more rapidly than if feeding normally in their natural environments. We used free ranging moose (Alces alces) in the Swedish mountains to test if feeding rates varied during a full feeding bout. Our analysis revealed that, over a foraging bout, bite and chew rates varied, as did bite size, which resulted in declining intake rates. Our results thus suggest that the existing model (parameterized over short durations with food-deprived animals) is probably adequate for small herbivores with short feeding bouts, but not for large herbivores with long foraging bouts like moose. We may thus need to modify the Spalinger - Hobbs foraging model, or better yet, parameterize it over a full foraging bout to faithfully reflect the longer time scales experienced by these larger herbivores

Published in

Title: Proceedings of the International Union of Game Biologists

Conference

International Union of Game Biologists XXVIII Congress