• DOI:10.1007/s00442-015-3328-0
• Corpus ID: 17050304

When to initiate torpor use? Food availability times the transition to winter phenotype in a tropical heterotherm

@article{Vuarin2015WhenTI,
  title={When to initiate torpor use? Food availability times the transition to winter phenotype in a tropical heterotherm},
  author={Pauline Vuarin and Melanie Dammhahn and Peter M. Kappeler and Pierre-Yves Henry},
  journal={Oecologia},
  year={2015},
  volume={179},
  pages={43-53}
}

• Pauline Vuarin, Melanie Dammhahn, +1 author P. Henry
• Published 8 May 2015
• Environmental Science
• Oecologia

Timing of winter phenotype expression determines individual chances of survival until the next reproductive season. Environmental cues triggering this seasonal phenotypic transition have rarely been investigated, although they play a central role in the compensation of climatic fluctuations via plastic phenotypic adjustments. Initiation of winter daily torpor use—a widespread energy-saving phenotype—could be primarily timed according to anticipatory seasonal cues (anticipatory cues hypothesis), or flexibly fine-tuned according to actual energy availability (food shortage hypothesis). We conducted a food supplementation experiment on wild heterothermic primates (grey mouse lemurs, Microcebus murinus) at the transition to the food-limited dry season, i.e. the austral winter. As expected under the food shortage hypothesis, food-supplemented individuals postponed the seasonal transition to normal torpor use by 1–2 month(s), spent four times less torpid, and exhibited minimal skin temperature 6 °C higher than control animals. This study provides the first in situ experimental evidence that food availability, rather than abiotic cues, times the launching of torpor use. Fine-tuning of the timing of seasonal phenotypic transitions according to actual food shortage should provide heterotherms with a flexible adaptive mechanism to survive unexpected environmental fluctuations.