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Journal of Chemical Ecology

, Volume 41, Issue 12, pp 1059–1068 | Cite as

Using the Specialization Framework to Determine Degree of Dietary Specialization in a Herbivorous Woodrat

  • Michele M. Skopec
  • Kevin D. Kohl
  • Katharina Schramm
  • James R. Halpert
  • M. Denise Dearing
Article

Abstract

To be considered a dietary specialist, mammalian herbivores must consume large quantities of a plant species considered “difficult” with respect to nutrient or toxin content, and possess specialized adaptations to deal with plant defensive compounds or low nutritional content. Populations of Neotoma lepida in the Great Basin consume Juniperus osteosperma, a plant heavily defended by terpenes, but a detailed dietary analysis of this population is lacking. Therefore, we investigated the extent of dietary specialization in this species in comparison with the better-studied specialist species, N. stephensi. Microhistological analysis of feces from N. lepida revealed that greater than 90 % of their diet in nature was comprised of juniper. In laboratory tolerance trials, N. lepida tolerated a diet of 80 % J. osteosperma, similar to that observed for N. stephensi. There was no difference in the abilities of N. lepida and N. stephensi to metabolize hexobarbital, a proxy compound for terpene metabolism. In preference tests of native and non-native juniper species, N. lepida did not exhibit a preference for its native or co-occurring juniper, J. osteosperma, over the non-native species, J. monosperma, whereas N. stephensi preferred its native or co-occurring juniper J. monosperma over non-native J. osteosperma. Behavioral and habitat differences between these woodrat species lead to the categorization of N. stephensi as an obligate juniper specialist with a small range that overlaps that of its preferred food, J. monosperma, and N. lepida as a facultative juniper specialist with a large range, and only a portion of its distribution containing populations that feed extensively on J. osteosperma.

Keywords

Dietary specialization Neotoma Juniper Herbivory 

Notes

Acknowledgments

We thank Andrew Corbin for his adept technical assistance. Support for this research came from NSF (IOS 1256383 and IOS 1461359).

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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Michele M. Skopec
    • 1
  • Kevin D. Kohl
    • 2
  • Katharina Schramm
    • 1
    • 2
  • James R. Halpert
    • 3
  • M. Denise Dearing
    • 2
  1. 1.Department of ZoologyWeber State UniversityOgdenUSA
  2. 2.Department of BiologyUniversity of UtahSalt Lake CityUSA
  3. 3.School of PharmacyUniversity of ConnecticutStorrsUSA

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