Hunt exhaustion

The low oxygen levels on the altiplano affect how viscachas and foxes lead their lives. The air is so thin that there is not enough oxygen for a sustained chase. A red fox (a culpeo or coloured fox) must be sneaky rather than swift to get close to prey. The viscachas never stray far from safety and run to a bolt hole when they spot the fox. Even after such a short dash, both fox and viscachas are gasping for breath.