These arboreal monkeys are fast moving and shy, so very little is known about their behaviour in the wild. They move mainly in leaps and jumps of up to 10m have been recorded, native people call them 'flying monkeys' for this reason. They rarely come to the ground and prefer the middle level of forests. They can run upright along branches. They are active during the daytime (diurnal). While usually silent in zoos they can make a loud call. An aggressive Saki monkey signals his displeasure with body shaking, foot stamping, pouffed hair, arched posture and a loud growl. They can make chirping sounds.