Document Detail


Integrating the costs of plant toxins and predation risk in foraging decisions of a mammalian herbivore.
MedLine Citation:
PMID:  20652597     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Foraging herbivores must satisfy their nutrient requirements in a world of toxic plants while also avoiding predators. Plant toxins and perceived predation risk at food patches should both reduce patch residency time, but the relative strengths of these factors on feeding decisions has rarely been quantified. Using an arboreal generalist herbivore, the common brushtail possum Trichosurus vulpecula, we tested the effects on food intake of the plant toxin, cineole, and regurgitated pellets from one of its predators, the powerful owl Ninox strenua at the small spatial scale of the food patch. We used the giving-up density (GUD) framework, with animals harvesting food items (sultanas) in an inedible matrix (small pebbles). We ran two consecutive field experiments in a eucalypt woodland in eastern Australia, 1 month apart in the same location. In experiment 1, there was a significant interaction between cineole [at 17% of dry matter (DM)] and owl pellets. The GUD was lowest in the absence of both cineole and owl pellet, intermediate in the presence of owl pellet; and highest with cineole ± owl pellet. The effect of owl pellet diminished over time. In experiment 2, only cineole (at 10% DM) increased the GUD significantly. The difference in effect of owl pellet was probably due to both habituation and freshness of the cue. Our study demonstrates the importance of synthesising predator-prey and plant-herbivore ecology to better understand the complex set of constraints influencing foraging herbivores. The greater effect of toxin than fear on possums is likely to be due to its high, but ecologically relevant concentration. This highlights the need to explore the relative and net impacts of a range of concentrations of plant toxins and predation risks.
Authors:
Sahar N Kirmani; Peter B Banks; Clare McArthur
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-07-21
Journal Detail:
Title:  Oecologia     Volume:  164     ISSN:  1432-1939     ISO Abbreviation:  Oecologia     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-09-15     Completed Date:  2011-01-24     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0150372     Medline TA:  Oecologia     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  349-56     Citation Subset:  IM    
Affiliation:
School of Biological Sciences, The University of Sydney, Sydney, NSW, Australia.
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MeSH Terms
Descriptor/Qualifier:
Animals
Cyclohexanols / pharmacology*
Eating
Feeding Behavior / drug effects*,  physiology
Monoterpenes / pharmacology*
Plants, Toxic / chemistry*
Predatory Behavior
Strigiformes
Trichosurus / physiology*
Chemical
Reg. No./Substance:
0/Cyclohexanols; 0/Monoterpenes; 470-82-6/cineole

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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