Influence of temperature on energy intake and food selection by macaques

I examined the influence of temperature on food intake in 4 captive macaques in a room with controlled temperature. I gave then? two types of artificial food pellets which were different in energy content per weighs in 6 conditions of air temperature. Total energy intake of macaques increased as temperature decreased Intake of low quality pellets increased significantly with decreasing temperature in 3 of 4 subjects. The other macaque, whose food intake was almost constant, decreased his body weight as ambient temperature decreased. These results suggest that energy requirements of macaques change with temperature as a result of changes in energy required for ther thermoregulation. Moreover temperature influenced the selectivity of lower quality food. I discuss the pattern of food selection found in this experiment from the view-point of optimal foraging strategy.