【動物学】ライオンとチーターはどのように獲物を追い詰めるのか

A detailed analysis of how lions chase down zebras and cheetah hunt impala is published online in Nature this week. The study reveals that, although the predators in each predator-prey pair are more athletic in terms of muscle power and capacity to speed up and slow down, the prey species can slip away at lower speeds at which they are more manoeuvrable.

Alan Wilson and colleagues studied locomotion in two predator-prey pairs - lion-zebra and cheetah-impala - in their natural savannah habitat in Botswana. The authors used specially designed collars to collect velocity and acceleration data from free-living wild animals (five cheetah, seven impala, nine lions and seven zebra) undertaking a combined total of over 5,000 high-speed runs in northern Botswana. They also measured muscle power by studying biopsies from the hind-leg biceps femoris muscle of six cheetah, five impala, eight lions and eight zebra.

The authors found that cheetah and impala were universally more athletic than lion and zebra, in terms of speed, acceleration and turning, but within each predator-prey pair, the predators had 20% higher muscle fibre power, 37% greater acceleration capacity and 72% greater deceleration capacity than their prey. Using these data, the authors simulated hunt dynamics and found that at lower speeds, the prey can use their maximum manoeuvring performance to elude the predator, while predators must be more athletic than their prey in order to sustain a viable success rate.

The findings also provide insights into predators’ preferred prey and hunting style. The authors’ model predicts a low success rate for lions hunting impala, for example, supporting the observation that they catch impala opportunistically rather than in an open pursuit.