Modeling trade‐offs between plant fiber and toxins: a framework for quantifying risks perceived by foraging herbivores. Issue 12 (1st December 2015)

• Record Type: Journal Article
• Authors: Camp, Meghan J.; Shipley, Lisa A.; Johnson, Timothy R.; Forbey, Jennifer Sorensen; Rachlow, Janet L.; Crowell, Miranda M.
• Is Part Of: Ecology. Volume 96:Issue 12(2015)
• Page Start: 3292
• Page End: 3302
• Publication Date: 2015-12-01
• Subjects: Brachylagus idahoensis -- equivalence point -- fiber -- marginal rate of substitution -- method of paired comparisons -- monoterpene -- mountain cottontail -- plant secondary metabolite -- pygmy rabbit -- sagebrush -- Sylvilagus nuttallii; Ecology -- Periodicals; Ecology -- Periodicals; Écologie -- Périodiques; Ecologie; Écologie; Écologie animale; Écologie végétale; Ecology; Periodicals; 577.05
• DOI: 10.1890/14-2412.1
• Languages: English
• ISSNs: 0012-9658

Abstract

Abstract : When selecting habitats, herbivores must weigh multiple risks, such as predation, starvation, toxicity, and thermal stress, forcing them to make fitness trade‐offs. Here, we applied the method of paired comparisons (PC) to investigate how herbivores make trade‐offs between habitat features that influence selection of food patches. The method of PC measures utility and the inverse of utility, relative risk, and makes trade‐offs and indifferences explicit by forcing animals to make choices between two patches with different types of risks. Using a series of paired‐choice experiments to titrate the equivalence curve and find the marginal rate of substitution for one risk over the other, we evaluated how toxin‐tolerant (pygmy rabbit Brachylagus idahoensis ) and fiber‐tolerant (mountain cottontail rabbit Sylviagus nuttallii ) herbivores differed in their hypothesized perceived risk of fiber and toxins in food. Pygmy rabbits were willing to consume nearly five times more of the toxin 1, 8‐cineole in their diets to avoid consuming higher levels of fiber than were mountain cottontails. Fiber posed a greater relative risk for pygmy rabbits than cottontails and cineole a greater risk for cottontails than pygmy rabbits. Our flexible modeling approach can be used to (1) quantify how animals evaluate and trade off multiple habitat attributes when the benefits and risks are difficult to quantify, and (2) integrate diverse risks that influence fitness and habitat selection into a single index of habitat value. This index potentially could be applied to landscapes to predict habitat selection across several scales.