|Nubian ibex planning his next climb|
photo: Chmee2, WikimediaCommons
In this setting, their fitness depends on their balance, agility, fearlessness, and some superior eye-hoof coordination.
Have a look at this amazing BBC film clip (David Attenborough narrating!) to watch this nearly newborn kid show off his fitness as he tries to outfox a fox. A definite cliff hanger!