Oecologia

, Volume 156, Issue 2, pp 333–340

Consumption of grass endophytes alters the ultraviolet spectrum of vole urine

  • Otso Huitu
  • Marjo Helander
  • Päivi Lehtonen
  • Kari Saikkonen
Plant-Animal Interactions - Original Paper

DOI: 10.1007/s00442-008-0984-3

Cite this article as:
Huitu, O., Helander, M., Lehtonen, P. et al. Oecologia (2008) 156: 333. doi:10.1007/s00442-008-0984-3

Abstract

Fungal endophytes of grasses are known to benefit their hosts directly by increasing resistance to herbivores through mycotoxins. We propose and test assumptions of a novel hypothesis according to which fungal endophytes of grasses may benefit their hosts also indirectly by increasing the conspicuousness of a mammalian herbivore, the field vole (Microtus agrestis), to its avian predators by enhancing the ultraviolet visibility of vole urine. We found that field voles feeding on endophyte-infected meadow ryegrass (Lolium pratense) lost body mass, while voles feeding on non-infected meadow ryegrass gained mass. More interestingly, the maximum peak intensity of ultraviolet fluorescence in the urine of voles feeding on endophyte-infected grass shifted from over 380 nm to circa 370 nm, which is the suggested maximum sensitivity of the ultraviolet pigments in the eyes of vole-eating raptors. Therefore, grazing on endophyte-infected grass alters the ultraviolet spectrum of vole urine, thus potentially enhancing its visibility to avian predators.

Keywords

Fluorescence Lolium pratense Microtus agrestis Predation Reflectance 

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Otso Huitu
    • 1
  • Marjo Helander
    • 2
    • 3
  • Päivi Lehtonen
    • 2
    • 3
  • Kari Saikkonen
    • 4
    • 5
  1. 1.Suonenjoki Research UnitFinnish Forest Research InstituteSuonenjokiFinland
  2. 2.Section of EcologyUniversity of TurkuTurkuFinland
  3. 3.Plant Production ResearchMTT Agrifood Research FinlandJokioinenFinland
  4. 4.Plant Production Research, Plant ProductionMTT Agrifood Research FinlandMikkeliFinland
  5. 5.Kevo Subarctic Research InstituteUniversity of TurkuTurkuFinland