The extraordinary athletic performance of leaping gibbons

The distance that animals leap depends on their take-off angle and velocity. The velocity is generated solely by mechanical work during the push-off phase of standing-start leaps. Gibbons are capable of exceptional leaping performance, crossing gaps in the forest canopy exceeding 10 m, yet possess none of the adaptations possessed by specialist leapers synonymous with maximizing mechanical work. To understand this impressive performance, we recorded leaps of the gibbons exceeding 3.7 m. Gibbons perform more mass-specific work (35.4 J kg−1) than reported for any other species to date, accelerating to 8.3 ms−1in a single movement and redefining our estimates of work performance by animals. This energy (enough for a 3.5 m vertical leap) is 60 per cent higher than that achieved by galagos, which are renowned for their remarkable leaping performance. The gibbons' unusual morphology facilitates a division of labour among the hind limbs, forelimbs and trunk, resulting in modest power requirements compared with more specialized leapers.