Journal of Comparative Physiology B

, Volume 176, Issue 3, pp 213–222

Field metabolic rates of phytophagous bats: do pollination strategies of plants make life of nectar-feeders spin faster?

  • Christian C. Voigt
  • Detlev H. Kelm
  • G. Henk Visser
Original Paper

DOI: 10.1007/s00360-005-0042-y

Cite this article as:
Voigt, C.C., Kelm, D.H. & Visser, G.H. J Comp Physiol B (2006) 176: 213. doi:10.1007/s00360-005-0042-y


Recently, it was argued that extrinsic factors, such as high foraging costs, lead to elevated field metabolic rates (FMR). We tested this suggestion by comparing the FMR of nectar-feeding and fruit-eating bats. We hypothesized that the foraging effort per energy reward is higher for nectar-feeding mammals than for fruit-eating mammals, since energy rewards at flowering plants are smaller than those at fruiting plants. Using the doubly labelled water method, we measured the FMR of nectar-feeding Glossophaga commissarisi and fruit-eating Carollia brevicauda, which coexisted in the same rainforest habitat and shared the same daytime roosts. Mass-specific FMR of G. commissarisi exceeded that of C. brevicauda by a factor of almost two: 5.3±0.6 kJ g−1 day−1 for G. commissarisi and 2.8±0.4 kJ g−1 day−1 for C. brevicauda. Since nectar-feeding bats imbibe nectar droplets of only 193 J energy content during each flower visit, a G. commissarisi bat has to perform several 100 flower visits per night to meet its energy requirement. The fruit-eating C. brevicauda, on the other hand, needs to harvest only 3–12 Piper infructescenses per night, as the energy reward per Piper equals ca. 6–30 kJ. We argue that the flowering and fruiting plants exert different selective forces on the foraging behaviour and energetics of pollinators and the seed dispersers, respectively. A comparison between nectar-feeding and non-nectar-feeding species in various vertebrate taxa demonstrates that pollinators have elevated FMRs.


Carollia Doubly labelled water Glossophaga Field metabolic rate Diet 



Body mass


Basal metabolic rate


Basal isotope enrichment


Initial isotope enrichment


Final isotope enrichment


Doubly labelled water


Hourly energy expenditure


Field metabolic rate


Fractional turnover of deuterium


Fractional turnover of 18O


Body water pool

\( r_{{{\text{CO}}_{2} }} \)

Rate of carbon dioxide production

\( r_{{{\text{H}}_{2} {\text{O}}}} \)

Rate of water flux


Respiratory quotient


Standard deviation


Time between the initial and final sample

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Christian C. Voigt
    • 1
  • Detlev H. Kelm
    • 1
  • G. Henk Visser
    • 2
  1. 1.Institute for Zoo and Wildlife Research, Evolutionary Ecology Research GroupBerlinGermany
  2. 2.Centre for Isotope ResearchAG GroningenThe Netherlands

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