Objectives: Little is known about the absolute pool of energy primates use in the wild and how this pool varies seasonally. It is also not fully understood why some species facing unpredictable changes in food supply and risks of energy imbalance show high breeding seasonality. We examined these issues in a folivorous gregarious lemur (Propithecus coronatus) in a dry forest of Madagascar.
Methods: We assessed energy input and activity budget in males and females from three groups during dry and wet months. Diet composition and daily food intake were determined using focal animal sampling and continuous recording of mouthfuls. Locomotion types and daily distances traveled were recorded. Time budget was determined using scan sampling, supplemented with a preliminary analysis of the energy budget using the factorial method.
Results: The macronutrient composition of the diet did not change markedly between seasons but a large increase in energy input arose during the early wet season. Activity was highest at this period but entailed only moderate increase in energy expenditure. Females did not ingest more energy than males despite female dominance. Both sexes exhibited a thrifty energy strategy and, possibly, fat storage.
Conclusions: Seasonal increase of daily energy input was likely related to male-male mating competition and females' need to reach physical condition prior to the dry season sufficient for reproducing. Sifakas may time their reproductive cycle according to the seasonal variation in day-length because recurrent patterns of low (dry season) versus high (wet season) food production occur despite years of food shortage. Am J Phys Anthropol, 2015. © 2015 Wiley Periodicals, Inc. Am J Phys Anthropol 158:269-278, 2015. © 2015 Wiley Periodicals, Inc.
Keywords: bioenergetics; energy input; food intake; primate; sexual competition.
© 2015 Wiley Periodicals, Inc.