Nutritional ecophysiology of the Andean mouse Abrothrix andinus: energy requirements, food quality and turnover time.

1. Abrothrix andinus (Rodentia: Cricetidae) is a small winter active mammal inhabiting the Andes range, enduring seasonal changes in food quality and ambient temperatures. 2. This species responds to seasonal changes in food quality and energy need by seasonal changes in nutrient transport by the small intestine. 3. Here I document significant increased digestive turnover time of individuals maintained under low food quality and high energy needs (Anova, P < 0.001). 4. Contrary to predictions, multifactorial Anova revealed that food quality did not explain the higher than expected turnover time. In this case, increased energy needs (low ambient temperature) appears to be of greatest importance. 5. Exposed to cold environmental conditions and/or under limitations in food quality and abundance, winter active small mammals may enhance their digestive efficiency by retaining food in their digestive tract for as long as possible.