Literaturdatenbank
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Murray, I. W., & Wolf, B. O. (2013). Desert tortoise (gopherus agassizii) dietary specialization decreases across a precipitation gradient. PLoS ONE, 28(8), e66505.
Added by: Admin (06 Jan 2014 18:25:03 UTC) |
| Resource type: Journal Article DOI: 10.1371/journal.pone.0066505 BibTeX citation key: Murray2013 View all bibliographic details  |
Categories: General Keywords: Ernährung - nutrition, Gopherus agassizii, Habitat - habitat, Nordamerika - North America, Schildkröten - turtles + tortoises, Testudinidae Creators: Murray, Wolf Collection: PLoS ONE |
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| Abstract |
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Testudinidae We studied the plant resource use between and within populations of desert tortoise (Gopherus agassizii) across a precipitation gradient in the Sonoran Desert of Arizona. The carbon and nitrogen stable isotope values in animal tissues are a reflection of the carbon and nitrogen isotope values in diet, and consequently represent a powerful tool to study animal feeding ecology. We measured the δ(13)C and δ(15)N values in the growth rings on the shells of tortoises in different populations to characterize dietary specialization and track tortoise use of isotopically distinct C4/CAM versus C3 plant resources. Plants using C3 photosynthesis are generally more nutritious than C4 plants and these trait differences can have important growth and fitness consequences for consumers. We found that dietary specialization decreases in successively drier and less vegetated sites, and that broader population niche widths are accompanied by an increase in the dietary variability between individuals. Our results highlight how individual consumer plant resource use is bounded under a varying regime of precipitation and plant productivity, lending insight into how intra-individual dietary specialization varies over a spatial scale of environmental variability
Added by: Admin |